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Prevention of Selenite-induced Cataractogenesis by Origanum vulgare Extract  

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Full Text Available The present study sought to assess antioxidant effect of Origanum vulgare extract in preventing selenite-induced cataractogenesis. This study was performed on Young white rats received sodium selenite (30 nmol g-1 birth weight subcutaneously on day 13 post partum during two months in 2009. Cataract formation and intensity was detected and measured by slit-lamp. Origanum vulgare (Ov extract (2 g kg-1 was given (1-2 times intraperitoneal at different times with respect to the selenite administration lens opacification was analyzed in selenite, selenite-Ov, Ov and control groups on day 7 after selenite administration. Ov extract have revealed a significant protective effect against selenite induced cataract when injected 1 and 2 day (2 times before selenite injection. There is a protective effect of Ov against selenite induced cataract formation. It is supposed that the anticataract effect of Ov extract could be based on direct or indirect antioxidant mechanisms.

M. Lashgari

2010-01-01

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The intrinsic apoptosis pathway mediates the pro-longevity response to mitochondrial ROS in C. elegans.  

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The increased longevity of the C. elegans electron transport chain mutants isp-1 and nuo-6 is mediated by mitochondrial ROS (mtROS) signaling. Here we show that the mtROS signal is relayed by the conserved, mitochondria-associated, intrinsic apoptosis signaling pathway (CED-9/Bcl2, CED-4/Apaf1, and CED-3/Casp9) triggered by CED-13, an alternative BH3-only protein. Activation of the pathway by an elevation of mtROS does not affect apoptosis but protects from the consequences of mitochondrial dysfunction by triggering a unique pattern of gene expression that modulates stress sensitivity and promotes survival. In vertebrates, mtROS induce apoptosis through the intrinsic pathway to protect from severely damaged cells. Our observations in nematodes demonstrate that sensing of mtROS by the apoptotic pathway can, independently of apoptosis, elicit protective mechanisms that keep the organism alive under stressful conditions. This results in extended longevity when mtROS generation is inappropriately elevated. These findings clarify the relationships between mitochondria, ROS, apoptosis, and aging. PMID:24813612

Yee, Callista; Yang, Wen; Hekimi, Siegfried

2014-05-01

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PGC-1? buffers ROS-mediated removal of mitochondria during myogenesis.  

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Mitochondrial biogenesis and mitophagy are recognized as critical processes underlying mitochondrial homeostasis. However, the molecular pathway(s) coordinating the balance between these cellular programs is still poorly investigated. Here, we show an induction of the nuclear and mitochondrial peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC-1?) during myogenesis, which in turn co-activates the transcription of nuclear and mtDNA-encoded mitochondrial genes. We demonstrate that PGC-1? also buffers oxidative stress occurring during differentiation by promoting the expression of antioxidant enzymes. Indeed, by downregulating PGC-1?, we observed an impairment of antioxidants expression, which was accompanied by a significant reactive oxygen species (ROS) burst and increase of oxidative damage to proteins. In parallel, we detected a decrease of mitochondrial mass and function as well as increased mitophagy through the ROS/FOXO1 pathway. Upon PGC-1? downregulation, we found ROS-dependent nuclear translocation of FOXO1 and transcription of its downstream targets including mitophagic genes such as LC3 and PINK1. Such events were significantly reverted after treatment with the antioxidant Trolox, suggesting that PGC-1? assures mitochondrial integrity by indirectly buffering ROS. Finally, the lack of PGC-1? gave rise to a decrease in MYOG and a strong induction of atrophy-related ubiquitin ligases FBXO32 (FBXO32), indicative of a degenerative process. Overall, our results reveal that in myotubes, PGC-1? takes center place in mitochondrial homeostasis during differentiation because of its ability to avoid ROS-mediated removal of mitochondria. PMID:25375380

Baldelli, S; Aquilano, K; Ciriolo, M R

2014-01-01

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Costunolide induces apoptosis by ROS-mediated mitochondrial permeability transition and cytochrome C release.  

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Costunolide is an active compound isolated from the root of Saussurea lappa Clarks, a Chinese medicinal herb, and is considered a therapeutic candidate for various types of cancers. Nevertheless, the pharmacological pathways of costunolide are still unknown. In this study, we investigate the effects of costunolide on the induction of apoptosis in HL-60 human leukemia cells and its putative pathways of action. Using apoptosis analysis, measurement of reactive oxygen species (ROS), and assessment of mitochondrial membrane potentials, we show that costunolide is a potent inducer of apoptosis, and facilitates its activity via ROS generation, thereby inducing mitochondrial permeability transition (MPT) and cytochrome c release to the cytosol. ROS production, mitochondrial alteration, and subsequent apoptotic cell death in costunolide-treated cells were blocked by the antioxidant N-acetylcystein (NAC). Cyclosporin A, a permeability transition inhibitor, also inhibited mitochondrial permeability transition and apoptosis. Our data indicate that costunolide induces the ROS-mediated mitochondrial permeability transition and resultant cytochrome c release. This is the first report on the mechanism of the anticancer effect of costunolide. PMID:11256490

Lee, M G; Lee, K T; Chi, S G; Park, J H

2001-03-01

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Cadmium-induced teratogenicity: Association with ROS-mediated endoplasmic reticulum stress in placenta  

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The placenta is essential for sustaining the growth of the fetus. An increased endoplasmic reticulum (ER) stress has been associated with the impaired placental and fetal development. Cadmium (Cd) is a potent teratogen that caused fetal malformation and growth restriction. The present study investigated the effects of maternal Cd exposure on placental and fetal development. The pregnant mice were intraperitoneally injected with CdCl2 (4.5 mg/kg) on gestational day 9. As expected, maternal Cd exposure during early limb development significantly increased the incidences of forelimb ectrodactyly in fetuses. An obvious impairment in the labyrinth, a highly developed tissue of blood vessels, was observed in placenta of mice treated with CdCl2. In addition, maternal Cd exposure markedly repressed cell proliferation and increased apoptosis in placenta. An additional experiment showed that maternal Cd exposure significantly upregulated the expression of GRP78, an ER chaperone. Moreover, maternal Cd exposure induced the phosphorylation of placental eIF2?, a downstream molecule of PERK signaling. In addition, maternal Cd exposure significantly increased the level of placental CHOP, another target of PERK signaling, indicating that the unfolded protein response (UPR) signaling was activated in placenta of mice treated with CdCl2. Interestingly, alpha-phenyl-N-t-butylnitrone, a free radical spin-trapping agent, significantly alleviated Cd-induced placental ER stress and UPR. Taken together, these results suggest that reactive oxygen species (ROS)-mediated ER stress might be involved in Cd-induced impairment on placental and fetal development. Antioxidants may be used as pharmacological agents to protect against Cd-induced fetal malformation and growth restriction. -- Highlights: ? Cd induces fetal malformation and growth restriction. ? Cd induced placental ER stress and UPR. ? PBN alleviates Cd-induced ER stress and UPR in placenta. ? ROS-mediated ER stress might be involved in Cd-induced placental impairments. ? ROS-mediated ER stress might be involved in Cd-induced fetal malformations.

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Suberoylanilide hydroxamic acid induces ROS-mediated cleavage of HSP90 in leukemia cells.  

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Heat shock protein 90 (HSP90) is a molecular chaperone that supports stability of client proteins. We found that HSP90 was cleaved to 55 kDa protein after treatment with histone deacetylase (HDAC) inhibitors including suberoylanilide hydroxamic acid (SAHA) in several leukemia cell lines. We further analyzed molecular changes induced by SAHA in K562 cells. The SAHA-induced cleavage of HSP90 was blocked by a pan-caspase inhibitor, z-VAD-fmk, implying that the process is dependent on caspase activity. However, the experiments using antagonistic and agonistic Fas antibodies revealed that the cleavage of HSP90 was not dependent on Fas signaling. SAHA induced generation of reactive oxygen species (ROS), and the cleavage of HSP90 was blocked by a ROS scavenger N-acetylcystein (NAC). We also confirmed that hydrogen peroxide (H2O2) induced cleavage of HSP90 in a similar manner. Caspase 2, 3, 4, 6, 8, and 10 were activated by treatment with SAHA, and the activities were reduced by the pretreatment of NAC. Treatment of the cells with caspase 10 inhihitor, but not other inhibitors of caspases activated by SAHA, prevented cleavage of HSP90 by SAHA. SAHA-induced ROS generation and HSP90 cleavage were dependent on newly synthesized unknown proteins. Taken together, our results suggest that the cleavage of HSP90 by SAHA is mediated by ROS generation and caspase 10 activation. HSP90 cleavage may provide an additional mechanism involved in anti-cancer effects of HDAC inhibitors. PMID:25119188

Park, Sangkyu; Park, Jeong-A; Kim, Young-Eun; Song, Sukgil; Kwon, Hyung-Joo; Lee, Younghee

2015-01-01

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ROS-mediated upregulation of Noxa overcomes chemoresistance in chronic lymphocytic leukemia.  

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In recent years considerable progress has been made in treatment strategies for chronic lymphocytic leukemia (CLL). However, the disease remains incurable because of the development of chemoresistance. Strategies to overcome resistance mechanisms are therefore highly needed. At least two mechanisms contribute to the development of resistance to drugs; acquired mutations resulting in a dysfunctional p53 response and shifts in the balance between apoptosis-regulating proteins. Platinum-based compounds have been successfully applied in relapsed lymphoma and recently also in high-risk CLL. In this study we investigated the efficacy and mechanism of action of cisplatinum (CDDP) in chemorefractory CLL. Independent of p53-functional status, CDDP acted synergistically with fludarabine (F-ara-A). The response involved generation of reactive oxygen species (ROS), which led to specific upregulation of the proapoptotic BH3-only protein Noxa. Induction of Noxa resulted in cell death by apoptosis as inhibition of caspase activation completely abrogated cell death. Furthermore, drug-resistance upon CD40-ligand stimulation, a model for the protective stimuli provided in lymph nodes, could also be overcome by CDDP/F-ara-A. ROS accumulation resulted in Noxa upregulation mainly at the transcriptional level and this was, at least in part, mediated by the mitogen-activated protein kinase p38. Finally, Noxa RNA-interference markedly decreased sensitivity to CDDP/F-ara-A, supporting a key role for Noxa as mediator between ROS signaling and apoptosis induction. Our data indicate that interference in the cellular redox balance can be exploited to overcome chemoresistance in CLL. PMID:20935673

Tonino, S H; van Laar, J; van Oers, M H; Wang, J Y; Eldering, E; Kater, A P

2011-02-10

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TSPO interacts with VDAC1 and triggers a ROS-mediated inhibition of mitochondrial quality control.  

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The 18-kDa TSPO (translocator protein) localizes on the outer mitochondrial membrane (OMM) and participates in cholesterol transport. Here, we report that TSPO inhibits mitochondrial autophagy downstream of the PINK1-PARK2 pathway, preventing essential ubiquitination of proteins. TSPO abolishes mitochondrial relocation of SQSTM1/p62 (sequestosome 1), and consequently that of the autophagic marker LC3 (microtubule-associated protein 1 light chain 3), thus leading to an accumulation of dysfunctional mitochondria, altering the appearance of the network. Independent of cholesterol regulation, the modulation of mitophagy by TSPO is instead dependent on VDAC1 (voltage-dependent anion channel 1), to which TSPO binds, reducing mitochondrial coupling and promoting an overproduction of reactive oxygen species (ROS) that counteracts PARK2-mediated ubiquitination of proteins. These data identify TSPO as a novel element in the regulation of mitochondrial quality control by autophagy, and demonstrate the importance for cell homeostasis of its expression ratio with VDAC1. PMID:25470454

Gatliff, Jemma; East, Daniel; Crosby, James; Abeti, Rosella; Harvey, Robert; Craigen, William; Parker, Peter; Campanella, Michelangelo

2014-12-01

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Sanguinarine induces apoptosis in human colorectal cancer HCT-116 cells through ROS-mediated Egr-1 activation and mitochondrial dysfunction.  

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We examined the effects of sanguinarine, a benzophenanthridine alkaloid, on reactive oxygen species (ROS) production and the association of these effects with apoptotic cell death in a human colorectal cancer HCT-116 cell line. Sanguinarine generated ROS, which was followed by a decrease in the mitochondrial membrane potential (MMP), the activation of caspase-9 and -3, and the down-regulation of anti-apoptotic proteins, such as Bcl2, XIAP and cIAP-1. Sanguinarine also promoted the activation of caspase-8 and truncation of Bid (tBid). However, the quenching of ROS generation by N-acetyl-l-cysteine, a scavenger of ROS, reversed the sanguinarine-induced apoptosis effects via inhibition of the MMP collapse, tBid expression, and activation of caspases. Sanguinarine also markedly induced the expression of the early growth response gene-1 (Egr-1) during the early period, after which expression level was decreased. In addition, HCT-116 cells transfected with Egr-1 siRNA displayed significant blockage of sanguinarine-induced apoptotic activity in a ROS-dependent manner. These observations clearly indicate that ROS, which are key mediators of Egr-1 activation and MMP collapse, are involved in the early molecular events in the sanguinarine-induced apoptotic pathway acting in HCT-116 cells. PMID:23660334

Han, Min Ho; Kim, Gi-Young; Yoo, Young Hyun; Choi, Yung Hyun

2013-07-01

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Evaluation of anticataract potential of Triphala in selenite-induced cataract: In vitro and in vivo studies  

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Triphala (TP) is composed of Emblica officinalis, Terminalia chebula, and Terminalia belerica. The present study was undertaken to evaluate its anticataract potential in vitro and in vivo in a selenite-induced experimental model of cataract. In vitro enucleated rat lenses were maintained in organ culture containing Dulbecco’s Modified Eagles Medium alone or with the addition of 100?M selenite. These served as the normal and control groups, respectively. In the test group, the medium was su...

Gupta, Suresh Kumar; Kalaiselvan, V.; Srivastava, Sushma; Agrawal, Shyam S.; Saxena, Rohit

2010-01-01

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Prevention of Selenite-Induced Cataratogenesis by Ginkgo biloba Extract (Egb761) in Wistar Rats.  

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Abstract Objective: To investigate whether Ginkgo biloba extract retards selenite-induced cataractogenesis in Wistar rat pups. Methods: On postpartum day eight, Group I rat pups (n?=?12) received an intraperitoneal injection of physiological saline. Groups II and III rat pups (n?=?12) received a subcutaneous injection of sodium selenite. Group III also received an intraperitoneal injection of G. biloba extract once daily on postpartum days 9-14. Both eyes of each pup were examined from postpartum day 16 up to day 30. After sacrifice, encapsulated pup lens were analyzed for mean activities of catalase, superoxide dismutase, glutathione peroxidase (GPx), glutathione S-transferase and glutathione reductase. In addition, the mean concentrations of reduced glutathione (GSH) and malondialdehyde were analyzed in samples of lens and serum. Results: Dense lenticular opacification occurs 100% in Group II, but only minimal opacification occurs in three pups of Group III (25%), no opacification in 75% of Group III, none in Group I. Compared with Groups I and III, Group II rat showed lower lenticular antioxidant enzyme activity, lower level of GSH, and higher level of malondidehyde (mean?±?standard deviation SD, p?

Cao, Shuqin; Gao, Mei; Wang, Ningli; Liu, Na; Du, Guanhua; Lu, Jianmin

2014-11-01

12

PKC? and ? possibly mediate FSH-induced mouse oocyte maturation via NOX-ROS-TACE cascade signaling pathway.  

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In mammals, gonadotropins stimulate oocyte maturation via the epidermal growth factor (EGF) network, and the protein kinase C (PKC) signaling pathway mediates this process. Tumor necrosis factor-? converting enzyme (TACE) is an important protein responding to PKC activation. However, the detailed signaling cascade between PKC and TACE in follicle-stimulating hormone (FSH)-induced oocyte maturation in vitro remains unclear. In this study, we found that rottlerin (mallotoxin, MTX), the inhibitor of PKC ? and ?, blocked FSH-induced maturation of mouse cumulus-oocyte complexes (COCs) in vitro. We further clarified the relationship between two molecules downstream of PKC ? and ? and TACE in COCs: nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and its products, reactive oxygen species (ROS). We proved that the respective inhibitors of NOX, ROS and TACE could block FSH-stimulated oocyte maturation dose-dependently, but these inhibitory effects could be reversed partially by amphiregulin (Areg), an EGF family member. Notably, inhibition of PKC ? and ? prevented FSH-induced translocation of two cytosolic components of NOX, p47phox and p67phox, to the plasma membrane in cumulus cells. Moreover, FSH-induced TACE activity in cumulus cells was decreased markedly by inhibition of NOX and ROS. In conclusion, PKC ? and ? possibly mediate FSH-induced meiotic resumption in mouse COCs via NOX-ROS-TACE signaling pathway. PMID:25350560

Chen, Qian; Zhang, Wenqiang; Ran, Hao; Feng, Lizhao; Yan, Hao; Mu, Xinyi; Han, Yingying; Liu, Wei; Xia, Guoliang; Wang, Chao

2014-01-01

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PKC? and ? Possibly Mediate FSH-Induced Mouse Oocyte Maturation via NOX-ROS-TACE Cascade Signaling Pathway  

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In mammals, gonadotropins stimulate oocyte maturation via the epidermal growth factor (EGF) network, and the protein kinase C (PKC) signaling pathway mediates this process. Tumor necrosis factor-? converting enzyme (TACE) is an important protein responding to PKC activation. However, the detailed signaling cascade between PKC and TACE in follicle-stimulating hormone (FSH)-induced oocyte maturation in vitro remains unclear. In this study, we found that rottlerin (mallotoxin, MTX), the inhibitor of PKC ? and ?, blocked FSH-induced maturation of mouse cumulus-oocyte complexes (COCs) in vitro. We further clarified the relationship between two molecules downstream of PKC ? and ? and TACE in COCs: nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) and its products, reactive oxygen species (ROS). We proved that the respective inhibitors of NOX, ROS and TACE could block FSH-stimulated oocyte maturation dose-dependently, but these inhibitory effects could be reversed partially by amphiregulin (Areg), an EGF family member. Notably, inhibition of PKC ? and ? prevented FSH-induced translocation of two cytosolic components of NOX, p47phox and p67phox, to the plasma membrane in cumulus cells. Moreover, FSH-induced TACE activity in cumulus cells was decreased markedly by inhibition of NOX and ROS. In conclusion, PKC ? and ? possibly mediate FSH-induced meiotic resumption in mouse COCs via NOX-ROS-TACE signaling pathway. PMID:25350560

Ran, Hao; Feng, Lizhao; Yan, Hao; Mu, Xinyi; Han, Yingying; Liu, Wei; Xia, Guoliang; Wang, Chao

2014-01-01

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ROS accumulation and IGF-IR inhibition contribute to fenofibrate/PPAR? -mediated inhibition of Glioma cell motility in vitro  

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Full Text Available Abstract Background Glioblastomas are characterized by rapid cell growth, aggressive CNS infiltration, and are resistant to all known anticancer regimens. Recent studies indicate that fibrates and statins possess anticancer potential. Fenofibrate is a potent agonist of peroxisome proliferator activated receptor alpha (PPAR? that can switch energy metabolism from glycolysis to fatty acid ?-oxidation, and has low systemic toxicity. Fenofibrate also attenuates IGF-I-mediated cellular responses, which could be relevant in the process of glioblastoma cell dispersal. Methods The effects of fenofibrate on Glioma cell motility, IGF-I receptor (IGF-IR signaling, PPAR? activity, reactive oxygen species (ROS metabolism, mitochondrial potential, and ATP production were analyzed in human glioma cell lines. Results Fenofibrate treatment attenuated IGF-I signaling responses and repressed cell motility of LN-229 and T98G Glioma cell lines. In the absence of fenofibrate, specific inhibition of the IGF-IR had only modest effects on Glioma cell motility. Further experiments revealed that PPAR?-dependent accumulation of ROS is a strong contributing factor in Glioma cell lines responses to fenofibrate. The ROS scavenger, N-acetyl-cysteine (NAC, restored cell motility, improved mitochondrial potential, and increased ATP levels in fenofibrate treated Glioma cell lines. Conclusions Our results indicate that although fenofibrate-mediated inhibition of the IGF-IR may not be sufficient in counteracting Glioma cell dispersal, PPAR?-dependent metabolic switch and the resulting ROS accumulation strongly contribute to the inhibition of these devastating brain tumor cells.

Del Valle Luis

2010-06-01

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Nuclear Translocation of B-Cell-Specific Transcription Factor, BACH2, Modulates ROS Mediated Cytotoxic Responses in Mantle Cell Lymphoma  

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BACH2, a B-cell specific transcription factor, plays a critical role in oxidative stress-mediated apoptosis. Bortezomib (VelcadeTM) is widely used to treat relapsed mantle cell lymphoma (MCL) patients despite varying clinical outcomes. As one of the potential mechanisms of action, bortezomib was reported to elicit endoplasmic reticulum (ER) stress which triggers reactive oxygen species (ROS). In the present study, we investigated the redox-sensitive intracellular mechanism that might play a c...

Chen, Zheng; Pittman, Eric F.; Romaguera, Jorge; Fayad, Luis; Wang, Michael; Neelapu, Sattva S.; Mclaughlin, Peter; Kwak, Larry; Mccarty, Nami

2013-01-01

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The Endogenous Nitric Oxide Mediates Selenium-Induced Phytotoxicity by Promoting ROS Generation in Brassica rapa  

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Selenium (Se) is suggested as an emerging pollutant in agricultural environment because of the increasing anthropogenic release of Se, which in turn results in phytotoxicity. The most common consequence of Se-induced toxicity in plants is oxidative injury, but how Se induces reactive oxygen species (ROS) burst remains unclear. In this work, histofluorescent staining was applied to monitor the dynamics of ROS and nitric oxide (NO) in the root of Brassica rapa under Se(IV) stress. Se(IV)-induced faster accumulation of NO than ROS. Both NO and ROS accumulation were positively correlated with Se(IV)-induced inhibition of root growth. The NO accumulation was nitrate reductase (NR)- and nitric oxide synthase (NOS)-dependent while ROS accumulation was NADPH oxidase-dependent. The removal of NO by NR inhibitor, NOS inhibitor, and NO scavenger could alleviate Se(IV)-induced expression of Br_Rbohs coding for NADPH oxidase and the following ROS accumulation in roots, which further resulted in the amelioration of Se(IV)-induced oxidative injury and growth inhibition. Thus, we proposed that the endogenous NO played a toxic role in B. rapa under Se(IV) stress by triggering ROS burst. Such findings can be used to evaluate the toxic effects of Se contamination on crop plants. PMID:25333984

Hu, Liang-Bin; Li, You-Qin; Chen, Jian; Yang, Li-Fei

2014-01-01

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ROS Mediate Proapoptotic and Antisurvival Activity of Oleanane Triterpenoid CDDO-Me in Ovarian Cancer Cells  

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Oleanane triterpenoids are broad-spectrum antiproliferative and proapoptotic agents. In this study, we investigated whether reactive oxygen species (ROS) play a role in the antitumor activity of methyl-2-cyano-3, 12-dioxooleana-1, 9(11)-dien-28-oate (CDDO-Me) in OVCAR-5 and MDAH 2774 ovarian cancer cells. Treatment with CDDO-Me caused the generation of ROS (H2O2) and pre-treatment with N-acetylcysteine (NAC) prevented the generation of ROS. NAC also blocked the inhibition of cell proliferatio...

Gao, Xiaohua; Liu, Yongbo; Deeb, Dorrah; Liu, Patricia; Liu, Annie; Arbab, Ali S.; Gautam, Subhash C.

2013-01-01

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Enhancement of dynein-mediated autophagosome trafficking and autophagy maturation by ROS in mouse coronary arterial myocytes.  

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Dynein-mediated autophagosome (AP) trafficking was recently demonstrated to contribute to the formation of autophagolysosomes (APLs) and autophagic flux process in coronary arterial myocytes (CAMs). However, it remains unknown how the function of dynein as a motor protein for AP trafficking is regulated under physiological and pathological conditions. The present study tested whether the dynein-mediated autophagy maturation is regulated by a redox signalling associated with lysosomal Ca(2+) release machinery. In primary cultures of CAMs, reactive oxygen species (ROS) including H2 O2 and O2 (-.) (generated by xanthine/xanthine oxidase) significantly increased dynein ATPase activity and AP movement, which were accompanied by increased lysosomal fusion with AP and APL formation. Inhibition of dynein activity by (erythro-9-(2-hydroxy-3-nonyl)adenine) (EHNA) or disruption of the dynein complex by dynamitin (DCTN2) overexpression blocked ROS-induced dynein activation, AP movement and APL formation, and resulted in an accumulation of AP along with a failed breakdown of AP. Antagonism of nicotinic acid adenine dinucleotide phosphate (NAADP)-mediated Ca(2+) signalling with NED-19 and PPADS abolished ROS-enhanced lysosomal Ca(2+) release and dynein activation in CAMs. In parallel, all these changes were also enhanced by overexpression of NADPH oxidase-1 (Nox1) gene in CAMs. Incubation with high glucose led to a marked O2 (-.) production compared with normoglycaemic CAMs, while Nox1 inhibitor ML117 abrogated this effect. Moreover, ML117 and NED-19 and PPADS significantly suppressed dynein activity and APL formation caused by high glucose. Taken together, these data suggest that ROS function as important players to regulate dynein-dependent AP trafficking leading to efficient autophagic maturation in CAMs. PMID:24912985

Xu, Ming; Li, Xiao-Xue; Chen, Yang; Pitzer, Ashley L; Zhang, Yang; Li, Pin-Lan

2014-11-01

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LKB1 reduces ROS-mediated cell damage via activation of p38.  

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Liver kinase B1 (LKB1, also known as serine/threonine kinase 11, STK11) is a tumor suppressor mutated in Peutz-Jeghers syndrome and in a variety of sporadic cancers. Herein, we demonstrate that LKB1 controls the levels of intracellular reactive oxygen species (ROS) and protects the genome from oxidative damage. Cells lacking LKB1 exhibit markedly increased intracellular ROS levels, excessive oxidation of DNA, increased mutation rates and accumulation of DNA damage, which are effectively prevented by ectopic expression of LKB1 and by incubation with antioxidant N-acetylcysteine. The role of LKB1 in suppressing ROS is independent of AMP-activated protein kinase, a canonical substrate of LKB1. Instead, under the elevated ROS, LKB1 binds to and maintains the activity of the cdc42-PAK1 (p21-activated kinase 1) complex, which triggers the activation of p38 and its downstream signaling targets, such as ATF-2, thereby enhancing the activity of superoxide dismutase-2 and catalase, two antioxidant enzymes that protect the cells from ROS accumulation, DNA damage and loss of viability. Our results provide a new paradigm for a non-canonical tumor suppressor function of LKB1 and highlight the importance of targeting ROS signaling as a potential therapeutic strategy for cancer cells lacking LKB1.Oncogene advance online publication, 29 September 2014; doi:10.1038/onc.2014.315. PMID:25263448

Xu, H-G; Zhai, Y-X; Chen, J; Lu, Y; Wang, J-W; Quan, C-S; Zhao, R-X; Xiao, X; He, Q; Werle, K D; Kim, H-G; Lopez, R; Cui, R; Liang, J; Li, Y-L; Xu, Z-X

2014-09-29

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Stage-Specific Expression of TNF? Regulates Bad/Bid-Mediated Apoptosis and RIP1/ROS-Mediated Secondary Necrosis in Birnavirus-Infected Fish Cells  

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Infectious pancreatic necrosis virus (IPNV) can induce Bad-mediated apoptosis followed by secondary necrosis in fish cells, but it is not known how these two types of cell death are regulated by IPNV. We found that IPNV infection can regulate Bad/Bid-mediated apoptotic and Rip1/ROS-mediated necrotic death pathways via the up-regulation of TNF? in zebrafish ZF4 cells. Using a DNA microarray and quantitative RT-PCR analyses, two major subsets of differentially expressed genes were characterize...

Wang, Wei-lun; Hong, Jiann-ruey; Lin, Gen-hwa; Liu, Wangta; Gong, Hong-yi; Lu, Ming-wei; Lin, Ching-chun; Wu, Jen-leih

2011-01-01

 
 
 
 
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Dryofragin, a phloroglucinol derivative, induces apoptosis in human breast cancer MCF-7 cells through ROS-mediated mitochondrial pathway.  

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Dryofragin is a phloroglucinol derivative extracted from Dryopteris fragrans (L.) Schott. In this study, the anticancer activity of dryofragin on human breast cancer MCF-7 cells was investigated. Dryofragin inhibited the growth of MCF-7 cells in a time and concentration-dependent manner. The cell viability was measured using MTT assay. After treatment with dryofragin for 72, 48 and 24 h, the IC?? values were 27.26, 37.51 and 76.10 ?M, respectively. Further analyses of DNA fragmentation and Annexin V-PI double-labeling indicated an induction of apoptosis. Dryofragin-treatment MCF-7 cells had a significantly accumulation of reactive oxygen species (ROS), as well as an increased percentage of cells with mitochondrial membrane potential (MMP) disruption. These phenomena were blocked by pretreatment for 2 h of MCF-7 cells with the antioxidant compound N-acetyl-L-cysteine (NAC, 5 mM). These results speak for the involvement of a ROS-mediated mitochondria-dependent pathway in dryofragin-induced apoptosis. Western blot results showed that dryofragin inhibited Bcl-2 and induced Bax expression which led to an activation of caspases-9 and -3 in the cytosol, and further cleavage of poly ADP-ribose polymerase (PARP) in the nucleus, then induced cell apoptosis. In conclusion, the present study provides evidence that dryofragin induces apoptosis in human breast cancer MCF-7 cells through a ROS-mediated mitochondrial pathway. PMID:22796323

Zhang, Ying; Luo, Meng; Zu, Yuangang; Fu, Yujie; Gu, Chengbo; Wang, Wei; Yao, Liping; Efferth, Thomas

2012-08-30

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Stevioside induced ROS-mediated apoptosis through mitochondrial pathway in human breast cancer cell line MCF-7.  

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Stevioside is a diterpene glycoside found in the leaf of Stevia rebaudiana, a traditional oriental medicinal herb, which has been shown to have various biological and ethno-medicinal activities including antitumor activity. In this study, we investigated the effects of stevioside on the cytotoxicity, induction of apoptosis, and the putative pathways of its action in human breast cancer cells (MCF-7). For the analysis of apoptotic pathway, measurement of reactive oxygen species (ROS) and assessment of mitochondrial transmembrane potential (MTP) were achieved. We showed that stevioside was a potent inducer of apoptosis and it conveyed the apoptotic signal via intracellular ROS generation; thereby inducing change in MTP and induction of mitochondrial mediated apoptotic pathway. Taken together, our data indicated that stevioside induces the ROS-mediated mitochondrial permeability transition and results in the increased expression of apoptotic proteins such as Bax, Bcl-2 and Caspase-9. Effect of stevioside on stress-related transcription factors like NF-E2-related factor-2 opens up a new vista for further studies. This is the first report on the mechanism of the antibreast cancer (in vitro) activity of stevioside. PMID:23061910

Paul, S; Sengupta, S; Bandyopadhyay, T K; Bhattacharyya, A

2012-01-01

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Estrogen-induced DNA synthesis in vascular endothelial cells is mediated by ROS signaling  

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Full Text Available Abstract Background Since estrogen is known to increase vascular endothelial cell growth, elevated estrogen exposure from hormone replacement therapy or oral contraceptives has the potential to contribute in the development of abnormal proliferative vascular lesions and subsequent thickening of the vasculature. How estrogen may support or promote vascular lesions is not clear. We have examined in this study whether estrogen exposure to vascular endothelial cells increase the formation of reactive oxygen species (ROS, and estrogen-induced ROS is involved in the growth of endothelial cells. Methods The effect of estrogen on the production of intracellular oxidants and the role of estrogen-induced ROS on cell growth was studied in human umbilical vein endothelial cells. ROS were measured by monitoring the oxidation of 2'7'-dichlorofluorescin by spectrofluorometry. Endothelial cell growth was measured by a colorimetric immunoassay based on BrdU incorporation into DNA. Results Physiological concentrations of estrogen (367 fmol and 3.67 pmol triggered a rapid 2-fold increase in intracellular oxidants in endothelial cells. E2-induced ROS formation was inhibited to basal levels by cotreatment with the mitochondrial inhibitor rotenone (2 ?M and xanthine oxidase inhibitor allopurinol (50 ?M. Inhibitors of NAD(PH oxidase, apocynin and DPI, did not block E2-induced ROS formation. Furthermore, the NOS inhibitor, L-NAME, did not prevent the increase in E2-induced ROS. These findings indicate both mitochondria and xanthine oxidase are the source of ROS in estrogen treated vascular endothelial cells. E2 treated cells showed a 2-fold induction of BrdU incorporation at 18 h which was not observed in cells exposed to vehicle alone. Cotreatment with ebselen (20 ?M and NAC (1 mM inhibited E2-induced BrdU incorporation without affecting the basal levels of DNA synthesis. The observed inhibitory effect of NAC and ebselen on E2-induced DNA synthesis was also shown to be dose dependent. Conclusion We have shown that estrogen exposure stimulates the rapid production of intracellular ROS and they are involved in growth signaling of endothelial cells. It appears that the early estrogen signaling does not require estrogen receptor genomic signaling because we can inhibit estrogen-induced DNA synthesis by antioxidants. Findings of this study may further expand research defining the underlying mechanism of how estrogen may promote vascular lesions. It also provides important information for the design of new antioxidant-based drugs or new antioxidant gene therapy to protect the cardiovascular health of individuals sensitive to estrogen.

Felty Quentin

2006-04-01

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ROS-mediated platelet generation: a microenvironment-dependent manner for megakaryocyte proliferation, differentiation, and maturation.  

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Platelets have an important role in the body because of their manifold functions in haemostasis, thrombosis, and inflammation. Platelets are produced by megakaryocytes (MKs) that are differentiated from haematopoietic stem cells via several consecutive stages, including MK lineage commitment, MK progenitor proliferation, MK differentiation and maturation, cell apoptosis, and platelet release. During differentiation, the cells migrate from the osteoblastic niche to the vascular niche in the bone marrow, which is accompanied by reactive oxygen species (ROS)-dependent oxidation state changes in the microenvironment, suggesting that ROS can distinctly influence platelet generation and function in a microenvironment-dependent manner. The objective of this review is to reveal the role of ROS in regulating MK proliferation, differentiation, maturation, and platelet activation, thereby providing new insight into the mechanism of platelet generation, which may lead to the development of new therapeutic agents for thrombocytopenia and/or thrombosis. PMID:23846224

Chen, S; Su, Y; Wang, J

2013-01-01

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ROS-Mediated Cytotoxic Effect of Copper(II Hydrazone Complexes against Human Glioma Cells  

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Full Text Available 2-Acetylpyridine acetylhydrazone (H2AcMe, 2-benzoylpyridine acetylhydrazone (H2BzMe and complexes [Cu(H2AcMeCl2] (1 and [Cu(H2BzMeCl2] (2 were assayed for their cytotoxicity against wild type p53 U87 and mutant p53 T98 glioma cells, and against MRC-5 fibroblast cells. Compounds 1 and 2 proved to be more active than the corresponding hydrazones against U87, but not against T98 cells. Compound 1 induced higher levels of ROS than H2AcMe in both glioma cell lines. H2AcMe and 1 induced lower levels of ROS in MRC5 than in U87 cells. Compound 2 induced lower levels of ROS in MRC5 than in T98 cells. The cytotoxic effect of 1 in U87 cells could be related to its ability to provoke the release of ROS, suggesting that the cytotoxicity of 1 might be somehow p53 dependent.

Angel A. Recio Despaigne

2014-10-01

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Stage-specific expression of TNF? regulates bad/bid-mediated apoptosis and RIP1/ROS-mediated secondary necrosis in Birnavirus-infected fish cells.  

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Infectious pancreatic necrosis virus (IPNV) can induce Bad-mediated apoptosis followed by secondary necrosis in fish cells, but it is not known how these two types of cell death are regulated by IPNV. We found that IPNV infection can regulate Bad/Bid-mediated apoptotic and Rip1/ROS-mediated necrotic death pathways via the up-regulation of TNF? in zebrafish ZF4 cells. Using a DNA microarray and quantitative RT-PCR analyses, two major subsets of differentially expressed genes were characterized, including the innate immune response gene TNF? and the pro-apoptotic genes Bad and Bid. In the early replication stage (0-6 h post-infection, or p.i.), we observed that the pro-inflammatory cytokine TNF? underwent a rapid six-fold induction. Then, during the early-middle replication stages (6-12 h p.i.), TNF? level was eight-fold induction and the pro-apoptotic Bcl-2 family members Bad and Bid were up-regulated. Furthermore, specific inhibitors of TNF? expression (AG-126 or TNF?-specific siRNA) were used to block apoptotic and necrotic death signaling during the early or early-middle stages of IPNV infection. Inhibition of TNF? expression dramatically reduced the Bad/Bid-mediated apoptotic and Rip1/ROS-mediated necrotic cell death pathways and rescued host cell viability. Moreover, we used Rip1-specific inhibitors (Nec-1 and Rip1-specific siRNA) to block Rip1 expression. The Rip1/ROS-mediated secondary necrotic pathway appeared to be reduced in IPNV-infected fish cells during the middle-late stage of infection (12-18 h p.i.). Taken together, our results indicate that IPNV triggers two death pathways via up-stream induction of the pro-inflammatory cytokine TNF?, and these results may provide new insights into the pathogenesis of RNA viruses. PMID:21304825

Wang, Wei-Lun; Hong, Jiann-Ruey; Lin, Gen-Hwa; Liu, Wangta; Gong, Hong-Yi; Lu, Ming-Wei; Lin, Ching-Chun; Wu, Jen-Leih

2011-01-01

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Chimaphilin induces apoptosis in human breast cancer MCF-7 cells through a ROS-mediated mitochondrial pathway.  

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Chimaphilin, 2,7-dimethyl-1,4-naphthoquinone, is extracted from pyrola [Passiflora incarnata Fisch.]. In this study, the anticancer activity and underlying mechanisms of chimaphilin toward human breast cancer MCF-7 cells are firstly investigated. Chimaphilin could inhibit the viability of MCF-7 cells in a concentration-dependent manner, and the IC50 value was 43.30?M for 24h. Chimaphilin markedly induced apoptosis through the investigation of characteristic apoptotic morphological changes, nuclear DNA fragmentation, annexin V-FITC/propidium iodide (PI) double staining. Flow cytometry assay revealed that chimaphilin triggered a significant generation of ROS and disruption of mitochondrial membrane potential. Additionally, western blotting assay showed that chimaphilin suppressed Bcl-2 level and enhanced Bad level, then activated caspase-9 and caspase-3, and further activated the poly ADP-ribose polymerase (PARP), finally induced cell apoptosis involving the mitochondrial pathway. Furthermore, free radical scavengers N-acetyl-L-cysteine (NAC) pretreatment test testified that chimaphilin could increase the generation of ROS, then induce cell apoptosis. In general, the present results demonstrated that chimaphilin induced apoptosis in human breast cancer MCF-7 cells via a ROS-mediated mitochondrial pathway. PMID:24793375

Ma, Wei-Dong; Zou, Yong-Peng; Wang, Peng; Yao, Xiao-Hui; Sun, Yao; Duan, Ming-Hui; Fu, Yu-Jie; Yu, Bo

2014-08-01

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mtDNA germ line variation mediated ROS generates retrograde signaling and induces pro-cancerous metabolic features.  

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mtDNA non-synonymous germ line variation (G10398A; p.A114T) has remained equivocal with least mechanistic understanding in showing an association with cancer. This has necessitated showing in-vitro how an over-expression within mitochondria of either of the variants produces higher intracellular ROS, resulting in differential anchorage dependent and independent growth. Both these features were observed to be relatively higher in ND3:114T variant. An elevated amount of intracellular carbonylated proteins and a reduced activity of a key glycolytic enzyme, Pyruvate kinase M2, along with high glucose uptake and lactate production were other pro-cancerous features observed. The retrograde signaling through surplus ROS was generated by post-ND3 over-expression regulated nuclear gene expression epigenetically, involving selectively the apoptotic-DDR-pathways. The feature of ND3 over-expression, inducing ROS mediated pro-cancerous features in the cells in in vitro, was replicated in a pilot study in a limited number of sporadic breast tumors, suggesting the importance of mitochondrial germ-line variant(s) in enabling the cells to acquire pro-cancerous features. PMID:25300428

Singh, Rajnish Kumar; Srivastava, Archita; Kalaiarasan, Ponnusamy; Manvati, Siddharth; Chopra, Rupali; Bamezai, Rameshwar N K

2014-01-01

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Nickel (II)-induced cytotoxicity and apoptosis in human proximal tubule cells through a ROS- and mitochondria-mediated pathway  

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Nickel compounds are known to be toxic and carcinogenic in kidney and lung. In this present study, we investigated the roles of reactive oxygen species (ROS) and mitochondria in nickel (II) acetate-induced cytotoxicity and apoptosis in the HK-2 human renal cell line. The results showed that the cytotoxic effects of nickel (II) involved significant cell death and DNA damage. Nickel (II) increased the generation of ROS and induced a noticeable reduction of mitochondrial membrane potential (MMP). Analysis of the sub-G1 phase showed a significant increase in apoptosis in HK-2 cells after nickel (II) treatment. Pretreatment with N-acetylcysteine (NAC) not only inhibited nickel (II)-induced cell death and DNA damage, but also significantly prevented nickel (II)-induced loss of MMP and apoptosis. Cell apoptosis triggered by nickel (II) was characterized by the reduced protein expression of Bcl-2 and Bcl-xL and the induced the protein expression of Bad, Bcl-Xs, Bax, cytochrome c and caspases 9, 3 and 6. The regulation of the expression of Bcl-2-family proteins, the release of cytochrome c and the activation of caspases 9, 3 and 6 were inhibited in the presence of NAC. These results suggest that nickel (II) induces cytotoxicity and apoptosis in HK-2 cells via ROS generation and that the mitochondria-mediated apoptotic signaling pathway may be involved in the positive regulation of nickel (II)-induced renal cytotoxicity.

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ROS mediate proapoptotic and antisurvival activity of oleanane triterpenoid CDDO-Me in ovarian cancer cells.  

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Oleanane triterpenoids are broad-spectrum antiproliferative and proapoptotic agents. In this study, we investigated whether reactive oxygen species (ROS) play a role in the antitumor activity of methyl-2-cyano-3, 12-dioxooleana-1, 9(11)-dien-28-oate (CDDO-Me) in OVCAR-5 and MDAH 2774 ovarian cancer cells. Treatment with CDDO-Me caused the generation of ROS (H(2)O(2)) and pre-treatment with N-acetylcysteine (NAC) prevented the generation of ROS. NAC also blocked the inhibition of cell proliferation by CDDO-Me. Likewise, NAC prevented the CDDO-Me-caused binding of fluorescein isothiocyanate (FITC)-tagged annexin V, cleavage of poly ADP-ribose polymerase-1 (PARP-1), procaspases-3, -8 and -9 and loss of mitochondrial membrane potential. CDDO-Me inhibited the expression of prosurvival phospho-AKT (p-AKT), phospho-mammalian target of rapamycin (p-mTOR) and nuclear factor-kappa B (NF-?B) (p65) signaling molecules and NF-?B-regulated antiapoptotic B-cell lymphoma-2 (BCL-2), B-cell lymphoma-extra large (BCL-xL), cellular inhibitor of apoptosis protein 1(c-IAP1) and survivin, but pre-treatment with NAC blocked the down-modulation of these signaling and antiapoptotic proteins by CDDO-Me. Together, these results indicate the pivotal role ROS play in the antiproliferative- and apoptosis-inducing activity of CDDO-Me in ovarian cancer cells; however, the role of ROS in the down-regulation of prosurvival AKT, mTOR, NF-?B and antiapoptotic BCL-2, BCL-xL, c-IAP1 and survivin warrants further investigation. PMID:23267148

Gao, Xiaohua; Liu, Yongbo; Deeb, Dorrah; Liu, Patricia; Liu, Annie; Arbab, Ali S; Gautam, Subhash C

2013-01-01

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Protective role of new nitrogen compounds on ROS/RNS-mediated damage to PC12 cells  

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Reactive oxygen (ROS) and nitrogen (RNS) species are known to be involved in many degenerative diseases. This study reports four new nitrogen compounds from organic synthesis, identified as FMA4, FMA7, FMA762 and FMA796, which differ mainly by the number of hydroxyl groups within their phenolic unit. Their potential role as antioxidants was evaluated in PC12 cells by assessing their protection against oxidative and nitrosative insults. The four compounds, and particularly FMA762 a...

Silva, Joa?o P.; Proenc?a, M. Fernanda R. P.; Coutinho, O. P.

2008-01-01

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Carnosol Induces ROS-Mediated Beclin1-Independent Autophagy and Apoptosis in Triple Negative Breast Cancer  

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Background In this study we investigated the in vitro and in vivo anticancer effect of carnosol, a naturally occurring polyphenol, in triple negative breast cancer. Results We found that carnosol significantly inhibited the viability and colony growth induced G2 arrest in the triple negative MDA-MB-231. Blockade of the cell cycle was associated with increased p21/WAF1 expression and downregulation of p27. Interestingly, carnosol was found to induce beclin1-independent autophagy and apoptosis in MDA-MB-231 cells. The coexistence of both events, autophagy and apoptosis, was confirmed by electron micrography. Induction of autophagy was found to be an early event, detected within 3 h post-treatment, which subsequently led to apoptosis. Carnosol treatment also caused a dose-dependent increase in the levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2). Moreover, we show that carnosol induced DNA damage, reduced the mitochondrial potential and triggered the activation of the intrinsic and extrinsic apoptotic pathway. Furthermore, we found that carnosol induced a dose-dependent generation of reactive oxygen species (ROS) and inhibition of ROS by tiron, a ROS scavenger, blocked the induction of autophagy and apoptosis and attenuated DNA damage. To our knowledge, this is the first report to identify the induction of autophagy by carnosol. Conclusion In conclusion our findings provide strong evidence that carnosol may be an alternative therapeutic candidate against the aggressive form of breast cancer and hence deserves more exploration. PMID:25299698

Al Dhaheri, Yusra; Attoub, Samir; Ramadan, Gaber; Arafat, Kholoud; Bajbouj, Khuloud; Karuvantevida, Noushad; AbuQamar, Synan; Eid, Ali; Iratni, Rabah

2014-01-01

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Neem (Azadirachta indica L.) leaf extract deteriorates oocyte quality by inducing ROS-mediated apoptosis in mammals.  

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Neem (Azadirachta indica L.) leaf has been widely used in ayurvedic system of medicine for fertility regulation for a long time. The molecular mechanism by which neem leaf regulates female fertility remains poorly understood. Animal studies suggest that aqueous neem leaf extract (NLE) induces reactive oxygen species (ROS) - mediated granulosa cell apoptosis. Granulosa cell apoptosis deprives oocytes from nutrients, survival factors and cell cycle proteins required for the achievement of meiotic competency of follicular oocytes prior to ovulation. Under this situation, follicular oocyte becomes more susceptible towards apoptosis after ovulation. The increased level of hydrogen peroxide (H2O2) inside the follicular fluid results in the transfer of H2O2 from follicular fluid to the oocyte. The increased level of H2O2 induces p53 activation and over expression of Bax protein that modulates mitochondrial membrane potential and trigger cytochrome c release. The increased cytosolic cytochrome c level induces caspase-9 and caspase-3 activities that trigger destruction of structural and specific proteins leading to DNA fragmentation and thereby oocyte apoptosis. Based on these animal studies, we propose that NLE induces generation of ROS and mitochondria-mediated apoptosis both in granulosa cells as well as in follicular oocyte. The induction of apoptosis deteriorates oocyte quality and thereby limits reproductive outcome in mammals. PMID:25197620

Chaube, Shail K; Shrivastav, Tulsidas G; Tiwari, Meenakshi; Prasad, Shilpa; Tripathi, Anima; Pandey, Ajai K

2014-01-01

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Ameliorative effect of acetyl-L-carnitine and/or nifedipine against selenite-induced cataractogenesis in young albino rats.  

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Free radical toxicity and calcium ion overload have been identified as the major two players in the causation of cataract. The current study was carried out to investigate the anti-cataractogenic effect of single and combined treatment with acetyl-l-carnitine and nifedipine in sodium selenite-induced cataract. Rat pups were divided into 5 groups; 1st group received intraperitoneal injection (i.p.) of saline and served as normal control, 2nd group received single subcutaneous injection of sodium selenite 30nmol/g body weight on p10 (postpartum day 10), 3rd and 4th groups received either acetyl-l-carnitine (200mg/kg, i.p.) or nifedipine (0.1mg/kg, i.p.) on p9, respectively, before the administration of sodium selenite, and the treatment continued till p14. Last group received the combined treatments of acetyl-l-carnitine and nifedipine in the same regimen. All animals were examined using a slit lamp and retroillumination then sacrificed on p30. Lenses were removed and processed for biochemical analyses, histopathological and electron microscopic examination. Selenite-treated groups showed significantly (P?0.05) lower values of redox system components (glutathione and glutathione reductase activity) and anti-oxidant enzymes? activities (superoxide dismutase and catalase) along with increased lipid peroxidation that was accompanied by 100% opacified crystalline lenses (mature cataract) with abnormal structure as detected by electron microscopy. It is concluded that acetyl-l-carnitine or nifedipine was able to partially protect against selenite-induced abnormalities. While, combined treatment with acetyl-l-carnitine and nifedipine was superior to individual treatments in slowing down the development of cataract by restoring the anti-oxidant defense and mitigating lipid peroxidation in the lens and hence represents an attractive anti-cataractogenic remedy. PMID:24530554

Farghaly, Lamiaa M; Ghobashy, Waleed A; Shoukry, Youssef; El-Azab, Mona F

2014-04-15

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Evaluation of anticataract potential of Triphala in selenite-induced cataract: In vitro and in vivo studies.  

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Triphala (TP) is composed of Emblica officinalis, Terminalia chebula, and Terminalia belerica. The present study was undertaken to evaluate its anticataract potential in vitro and in vivo in a selenite-induced experimental model of cataract. In vitro enucleated rat lenses were maintained in organ culture containing Dulbecco's Modified Eagles Medium alone or with the addition of 100?M selenite. These served as the normal and control groups, respectively. In the test group, the medium was supplemented with selenite and different concentrations of TP aqueous extract. The lenses were incubated for 24 h at 37°C. After incubation, the lenses were processed to estimate reduced glutathione (GSH), lipid peroxidation product, and antioxidant enzymes. In vivo selenite cataract was induced in 9-day-old rat pups by subcutaneous injection of sodium selenite (25 ?mole/kg body weight). The test groups received 25, 50, and 75 mg/kg of TP intraperitoneally 4 h before the selenite challenge. At the end of the study period, the rats' eyes were examined by slit-lamp. TP significantly (P < 0.01) restored GSH and decreased malondialdehyde levels. A significant restoration in the activities of antioxidant enzymes such as superoxide dismutase (P < 0.05), catalase (P < 0.05), glutathione peroxidase (P < 0.05), and glutathione-s-transferase (P < 0.005) was observed in the TP-supplemented group compared to controls. In vivo TF 25mg/kg developed only 20% nuclear cataract as compared to 100% in control. TP prevents or retards experimental selenite-induced cataract. This effect may be due to antioxidant activity. Further studies are warranted to explore its role in human cataract. PMID:21731375

Gupta, Suresh Kumar; Kalaiselvan, V; Srivastava, Sushma; Agrawal, Shyam S; Saxena, Rohit

2010-10-01

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Cracking the Cytotoxicity Code: Apoptotic Induction of 10-Acetylirciformonin B is Mediated through ROS Generation and Mitochondrial Dysfunction  

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Full Text Available A marine furanoterpenoid derivative, 10-acetylirciformonin B (10AB, was found to inhibit the proliferation of leukemia, hepatoma, and colon cancer cell lines, with selective and significant potency against leukemia cells. It induced DNA damage and apoptosis in leukemia HL 60 cells. To fully understand the mechanism behind the 10AB apoptotic induction against HL 60 cells, we extended our previous findings and further explored the precise molecular targets of 10AB. We found that the use of 10AB increased apoptosis by 8.9%–87.6% and caused disruption of mitochondrial membrane potential (MMP by 15.2%–95.2% in a dose-dependent manner, as demonstrated by annexin-V/PI and JC-1 staining assays, respectively. Moreover, our findings indicated that the pretreatment of HL 60 cells with N-acetyl-l-cysteine (NAC, a reactive oxygen species (ROS scavenger, diminished MMP disruption and apoptosis induced by 10AB, suggesting that ROS overproduction plays a crucial rule in the cytotoxic activity of 10AB. The results of a cell-free system assay indicated that 10AB could act as a topoisomerase catalytic inhibitor through the inhibition of topoisomerase II?. On the protein level, the expression of the anti-apoptotic proteins Bcl-xL and Bcl-2, caspase inhibitors XIAP and survivin, as well as hexokinase II were inhibited by the use of 10AB. On the other hand, the expression of the pro-apoptotic protein Bax was increased after 10AB treatment. Taken together, our results suggest that 10AB-induced apoptosis is mediated through the overproduction of ROS and the disruption of mitochondrial metabolism.

Huei-Chuan Shih

2014-05-01

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Cracking the Cytotoxicity Code: Apoptotic Induction of 10-Acetylirciformonin B is Mediated through ROS Generation and Mitochondrial Dysfunction  

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A marine furanoterpenoid derivative, 10-acetylirciformonin B (10AB), was found to inhibit the proliferation of leukemia, hepatoma, and colon cancer cell lines, with selective and significant potency against leukemia cells. It induced DNA damage and apoptosis in leukemia HL 60 cells. To fully understand the mechanism behind the 10AB apoptotic induction against HL 60 cells, we extended our previous findings and further explored the precise molecular targets of 10AB. We found that the use of 10AB increased apoptosis by 8.9%–87.6% and caused disruption of mitochondrial membrane potential (MMP) by 15.2%–95.2% in a dose-dependent manner, as demonstrated by annexin-V/PI and JC-1 staining assays, respectively. Moreover, our findings indicated that the pretreatment of HL 60 cells with N-acetyl-l-cysteine (NAC), a reactive oxygen species (ROS) scavenger, diminished MMP disruption and apoptosis induced by 10AB, suggesting that ROS overproduction plays a crucial rule in the cytotoxic activity of 10AB. The results of a cell-free system assay indicated that 10AB could act as a topoisomerase catalytic inhibitor through the inhibition of topoisomerase II?. On the protein level, the expression of the anti-apoptotic proteins Bcl-xL and Bcl-2, caspase inhibitors XIAP and survivin, as well as hexokinase II were inhibited by the use of 10AB. On the other hand, the expression of the pro-apoptotic protein Bax was increased after 10AB treatment. Taken together, our results suggest that 10AB-induced apoptosis is mediated through the overproduction of ROS and the disruption of mitochondrial metabolism. PMID:24857964

Shih, Huei-Chuan; El-Shazly, Mohamed; Juan, Yung-Shun; Chang, Chao-Yuan; Su, Jui-Hsin; Chen, Yu-Cheng; Shih, Shou-Ping; Chen, Huei-Mei; Wu, Yang-Chang; Lu, Mei-Chin

2014-01-01

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Involvement of calcium-mediated effects on ROS metabolism in the regulation of growth improvement under salinity.  

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Salinity reduces Ca(2+) availability, transport, and mobility to growing regions of the plant and supplemental Ca(2+) is known to reduce salinity damages. This study was undertaken to unravel some of the ameliorative mechanisms of Ca(2+) on salt stress at the cellular and tissue levels. Zea mays L. plants were grown in nutrient solution containing 1 or 80 mM NaCl with various Ca(2+) levels. Measurements of growth and physiological parameters, such as ion imbalance, indicated that the Ca(2+)-induced alleviation mechanisms differed between plant organs. Under salinity, H(2)O(2) levels increased in the leaf-growing tissue with increasing levels of supplemental Ca(2+) and reached the levels of control plants, whereas superoxide levels remained low at all Ca(2+) levels, indicating that Ca(2+) affected growth by increasing H(2)O(2) but not superoxide levels. Salinity completely abolished apoplastic peroxidase activity. Supplemental Ca(2+) increased its activity only slightly. However, under salinity, polyamine oxidase (PAO) activity was shifted toward the leaf base probably as an adaptive mechanism aimed at restoring normal levels of reactive oxygen species (ROS) at the expansion zone where NADPH oxidase could no longer provide the required ROS for growth. Interestingly, addition of Ca(2+) shifted the PAO-activity peak back to its original location in addition to its enhancement. The increase in PAO activity in conjunction with low levels of apoplastic peroxidase is supportive of cellular growth via nonenzymatic wall loosening derived by the increase in H(2)O(2) and less supportive of the peroxidase-mediated cross-linking of wall material. Thus extracellular Ca(2+) can modulate ROS levels at specific tissue localization and developmental stages thereby affecting cellular extension. PMID:21466848

Shoresh, Michal; Spivak, Marina; Bernstein, Nirit

2011-09-15

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The NOX2-mediated ROS producing capacity of recipient cells is associated with reduced T cell infiltrate in an experimental model of chronic renal allograft inflammation.  

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We previously showed that anti-inflammatory Mph (Mph2) can both in vitro and in vivo induce regulatory T cells (Tregs) in a reactive oxygen species (ROS)-dependent fashion. As influx of Mph is an important characteristic of chronic inflammatory responses, we investigated the impact of NOX2-mediated ROS production by recipient cells in an experimental model of chronic allograft inflammation. We used a kidney transplantation (Tx) model with Lewis (Lew) rats as donor and congenic DA.Ncf1(DA/DA) (low ROS) and DA.Ncf1(E3/E3) (normal ROS) rats as recipients. At day 7 the contralateral kidney was removed, and the animals were sacrificed four weeks after Tx. Renal function and injury were monitored in serum and urine and the composition of the infiltrate was analyzed by immunohistochemistry. Four weeks after Tx, large leukocyte clusters were observed in the allograft, in which signs of ROS production could be demonstrated. These clusters showed no difference regarding composition of myeloid cells or the number of FoxP3 positive cells. However, T cell infiltrate was significantly reduced in the DA.Ncf1(E3/E3) recipients having normal ROS production. Therefore, this study suggests a regulatory effect of ROS on T cell infiltration, but no effect on other inflammatory cells in the allograft. PMID:24365514

Kraaij, Marina D; Koekkoek, Karin M; Gelderman, Kyra A; van Kooten, Cees

2014-03-01

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Shikonin targets cytosolic thioredoxin reductase to induce ROS-mediated apoptosis in human promyelocytic leukemia HL-60 cells.  

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Shikonin, a major active component of the Chinese herbal plant Lithospermum erythrorhizon, has been applied for centuries in traditional Chinese medicine. Although shikonin demonstrates potent anticancer efficacy in numerous types of human cancer cells, the cellular targets of shikonin have not been fully defined. We report here that shikonin may interact with the cytosolic thioredoxin reductase (TrxR1), an important selenocysteine (Sec)-containing antioxidant enzyme with a C-terminal -Gly-Cys-Sec-Gly active site, to induce reactive oxygen species (ROS)-mediated apoptosis in human promyelocytic leukemia HL-60 cells. Shikonin primarily targets the Sec residue in TrxR1 to inhibit its physiological function, but further shifts the enzyme to an NADPH oxidase to generate superoxide anions, which leads to accumulation of ROS and collapse of the intracellular redox balance. Importantly, overexpression of functional TrxR1 attenuates the cytotoxicity of shikonin, whereas knockdown of TrxR1 sensitizes cells to shikonin treatment. Targeting TrxR1 with shikonin thus discloses a previously unrecognized mechanism underlying the biological activity of shikonin and provides an in-depth insight into the action of shikonin in the treatment of cancer. PMID:24583460

Duan, Dongzhu; Zhang, Baoxin; Yao, Juan; Liu, Yaping; Fang, Jianguo

2014-05-01

 
 
 
 
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Chamaejasmine Induces Apoptosis in Human Lung Adenocarcinoma A549 Cells through a Ros-Mediated Mitochondrial Pathway  

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Full Text Available In the present study, the anticancer activity of chamaejasmine towards A549 human lung adenocarcinoma cells was investigated. In order to explore the underlying mechanism of cell growth inhibition of chamaejasmine, cell cycle distribution, ROS generation, mitochondrial membrane potential (??m disruption, and expression of cytochrome c, Bax, Bcl-2, caspase-3, caspase-9 and PARP were measured in A549 cells. Chamaejasmine inhibited the growth of A549 cells in a time and dose-dependent manner. The IC50 value was 7.72 µM after 72 h treatment. Chamaejasmine arrested the cell cycle in the G2/M phase and induced apoptosis via a ROS-mediated mitochondria-dependent pathway. Western blot analysis showed that chamaejasmine inhibited Bcl-2 expression and induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascade, and active-caspase-3 was involved in PARP cleavage. All of these signal transduction pathways are involved in initiating apoptosis. To the best of our knowledge, this is the first report demonstrating the cytotoxic activity of chamaejasmine towards A549 in vitro.

Lina Xing

2011-09-01

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SAH-induced MMP activation and K V current suppression is mediated via both ROS-dependent and ROS-independent mechanisms.  

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Voltage-gated potassium (K V) channels regulate cerebral artery tone and have been implicated in subarachnoid hemorrhage (SAH)-induced pathologies. Here, we examined whether matrix metalloprotease (MMP) activation contributes to SAH-induced K V current suppression and cerebral artery constriction via activation of epidermal growth factor receptors (EGFRs). Using patch clamp electrophysiology, we observed that K V currents were selectively decreased in cerebral artery myocytes isolated from SAH model rabbits. Consistent with involvement of enhanced MMP and EGFR activity in SAH-induced K V current suppression, we found that: (1) oxyhemoglobin (OxyHb) and/or the exogenous EGFR ligand, heparin-binding EGF-like growth factor (HB-EGF), failed to induce further K V current suppression after SAH and (2) gelatin zymography detected significantly higher MMP-2 activity after SAH. The removal of reactive oxygen species (ROS) by combined treatment with superoxide dismutase (SOD) and catalase partially inhibited OxyHb-induced K V current suppression. However, these agents had little effect on OxyHb-induced MMP-2 activation. Interestingly, in the presence of a broad-spectrum MMP inhibitor (GM6001), OxyHb failed to cause K V current suppression. These data suggest that OxyHb suppresses K V currents through both ROS-dependent and ROS-independent pathways involving MMP activation. The ROS-independent pathway involves activation of MMP-2, whereas the ROS-dependent pathway involves activation of a second unidentified MMP or ADAM (a disintegrin and metalloprotease domain). PMID:25366605

Koide, Masayo; Wellman, George C

2015-01-01

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Tumor-targeting novel manganese complex induces ROS-mediated apoptotic and autophagic cancer cell death.  

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In this study, the antitumor activity of the novel manganese (II) compound, Adpa-Mn {[(Adpa)Mn(Cl)(H2O)] (Adpa=bis(2-pyridylmethyl)amino-2-propionic acid)}, and its possible mechanisms of action were investigated. In vitro, the growth inhibitory effects of Adpa-Mn (with IC50 values lower than 15 µM) on tumor cell lines were examined by MTT assay. We found that this compound was more selective against cancer cells than the popular chemotherapeutic reagent, cisplatin. We then found that Adpa-Mn achieved its selectivity against cancer cells through the transferrin (Tf)-transferrin receptor (TfR) system, which is highly expressed in tumor cells. Furthermore, Adpa-Mn induced both apoptosis and autophagy, as indicated by chromatin condensation, the activation of poly(ADP-ribose) polymerase (PARP), Annexin V/propidium iodide staining, an enhanced fluorescence intensity of monodansylcadaverine (MDC), as well as the elevated expression of the autophagy-related protein, microtubule-associated protein 1 light chain 3 (LC3). In addition, Adpa-Mn induced the generation of intracellular reactive oxygen species (ROS) and its anticancer effects were significantly reduced following pre-treatment with the antioxidant, N-acetyl cysteine, indicating that ROS triggered cell death. In vivo, the induction of apoptosis and autophagy in tumor tissue was confirmed following treatment with Adpa-Mn, which contributed to its significant antitumor activity against hepatocellular carcinoma (Hep-A cell) xenografts at 10 mg/kg. Taken together, these data suggest the possible use of Adpa-Mn as a novel anticancer drug. PMID:25604962

Liu, Jia; Guo, Wenjie; Li, Jing; Li, Xiang; Geng, Ji; Chen, Qiuyun; Gao, Jing

2015-03-01

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Niclosamide enhances ROS-mediated cell death through c-Jun activation.  

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Radiotherapy is an effective treatment modality in the clinical treatment of cancers, and has been combined with chemotherapy in order to improve therapeutic efficacy. Therefore, we aimed to develop small molecules that enhance the cytotoxic effects of radiotherapy. In this study, we provide evidence that niclosamide is an effective radiosensitizer in non-small cell lung cancer cells. Using a cell-based high-throughput viability screen of 1040 compounds in combination with ?-ionizing radiation (IR), we found niclosamide, an FDA-approved antihelminthic agent, had a radiosensitizing effect on H1299 human lung cancer cells. Pretreatment with niclosamide enhanced IR- induced cell death of H1299 in a dose-dependent manner via apoptosis compared with IR or niclosamide alone. The combined treatment induced significantly more phosphorylation of p38 MAPK and c-Jun in H1299 cells than IR or niclosamide alone. Since IR induces apoptosis through generation of reactive oxygen species (ROS), hydrogen peroxide (H2O2) was employed as another ROS generator and we found that niclosamide also sensitized cells to H2O2. Niclosamide pretreatment also induced c-Jun and its phosphorylation in the presence of H2O2, thereby enhancing apoptosis. N-acetyl-L-cysteine (NAC) treatment abolished both cell death and c-Jun activation induced by the combination treatments. Knockdown of c-Jun also decreased PARP cleavage and clonogenic cell survival in niclosamide- and IR-treated H1299 cells. Our findings suggest that niclosamide could be a promising radiosensitizer in lung cancer patients through activation of the p38 MAPK-c-Jun axis. PMID:24750999

Lee, Sae-lo-oom; Son, A-Rang; Ahn, Jiyeon; Song, Jie-Young

2014-06-01

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Coenzyme Q10 Protects Astrocytes from ROS-Induced Damage through Inhibition of Mitochondria-Mediated Cell Death Pathway  

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Coenzyme Q10 (CoQ10) acts by scavenging reactive oxygen species to protect neuronal cells against oxidative stress in neurodegenerative diseases. The present study was designed to examine whether CoQ10 was capable of protecting astrocytes from reactive oxygen species (ROS) mediated damage. For this purpose, ultraviolet B (UVB) irradiation was used as a tool to induce ROS stress to cultured astrocytes. The cells were treated with 10 and 25 ?g/ml of CoQ10 for 3 or 24 h prior to the cells being exposed to UVB irradiation and maintained for 24 h post UVB exposure. Cell viability was assessed by MTT conversion assay. Mitochondrial respiration was assessed by respirometer. While superoxide production and mitochondrial membrane potential were measured using fluorescent probes, levels of cytochrome C (cyto-c), cleaved caspase-9, and caspase-8 were detected using Western blotting and/or immunocytochemistry. The results showed that UVB irradiation decreased cell viability and this damaging effect was associated with superoxide accumulation, mitochondrial membrane potential hyperpolarization, mitochondrial respiration suppression, cyto-c release, and the activation of both caspase-9 and -8. Treatment with CoQ10 at two different concentrations started 24 h before UVB exposure significantly increased the cell viability. The protective effect of CoQ10 was associated with reduction in superoxide, normalization of mitochondrial membrane potential, improvement of mitochondrial respiration, inhibition of cyto-c release, suppression of caspase-9. Furthermore, CoQ10 enhanced mitochondrial biogenesis. It is concluded that CoQ10 may protect astrocytes through suppression of oxidative stress, prevention of mitochondrial dysfunction, blockade of mitochondria-mediated cell death pathway, and enhancement of mitochondrial biogenesis. PMID:25552930

Jing, Li; He, Mao-Tao; Chang, Yue; Mehta, Suresh L.; He, Qing-Ping; Zhang, Jian-Zhong; Li, P. Andy

2015-01-01

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Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways  

Energy Technology Data Exchange (ETDEWEB)

Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G{sub 2}/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45?. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-? or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ? The mode of NaF-induced cell death and the mechanisms involved were examined. ? NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ? NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ? JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ? ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

Nguyen Ngoc, Tam Dan [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Son, Young-Ok [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Lim, Shin-Saeng [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin [Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Kim, Jong-Ghee [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Heo, Jung Sun [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Choe, Youngji [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Jeon, Young-Mi, E-mail: young@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Institute of Oral Biosciences and School of Dentistry (BK21 Program), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Graduate Center for Toxicology, School of Medicine, University of Kentucky, Lexington, KY 40536-0305 (United States); Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

2012-03-15

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Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways  

International Nuclear Information System (INIS)

Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner. Further, no information is available on the effects of NaF on mouse embryonic stem cells (mESCs). We investigated the mode of cell death induced by NaF and the mechanisms involved. NaF treatment greater than 1 mM reduced viability and DNA synthesis in mESCs and induced cell cycle arrest in the G2/M phase. The addition of NaF induced cell death mainly by apoptosis rather than necrosis. Catalase (CAT) treatment significantly inhibited the NaF-mediated cell death and also suppressed the NaF-mediated increase in phospho-c-Jun N-terminal kinase (p-JNK) levels. Pre-treatment with SP600125 or z-VAD-fmk significantly attenuated the NaF-mediated reduction in cell viability. In contrast, intracellular free calcium chelator, but not of sodium or calcium ion channel blockers, facilitated NaF-induced toxicity in the cells. A JNK specific inhibitor (SP600125) prevented the NaF-induced increase in growth arrest and the DNA damage-inducible protein 45?. Further, NaF-mediated loss of mitochondrial membrane potential was apparently inhibited by pifithrin-? or CAT inhibitor. These findings suggest that NaF affects viability of mESCs in a concentration-dependent manner, where more than 1 mM NaF causes apoptosis through hydroxyl radical-dependent and caspase- and JNK-mediated pathways. -- Highlights: ? The mode of NaF-induced cell death and the mechanisms involved were examined. ? NaF induced mainly apoptotic death of mouse embryonic stem cells (mESCs). ? NaF induced mitochondrial-mediated and caspase-dependent apoptosis. ? JNK- and p53-mediated pathways are involved in NaF-mediated apoptosis in the cells. ? ROS are the up-stream effector in NaF-mediated activation of JNK and p53 in mESCs.

48

ROS Enhances CXCR4-mediated Functions through Inactivation of PTEN in Prostate Cancer Cells  

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Inactivation of the tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is heavily implicated in the tumorigenesis of prostate cancer. Conversely, the upregulation of the chemokine (CXC) receptor 4 (CXCR4) is associated with prostate cancer progression and metastasis. Studies have shown that loss of PTEN permits CXCR4-mediated functions in prostate cancer cells. Loss of PTEN function is typically due to genetic and epigenetic modulations, as well as active site oxi...

Chetram, Mahandranauth A.; Don-salu-hewage, Ayesha S.; Hinton, Cimona V.

2011-01-01

49

Prolonged exposure of cortical neurons to oligomeric amyloid-? impairs NMDA receptor function via NADPH oxidase-mediated ROS production: protective effect of green tea (–-epigallocatechin-3-gallate  

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Full Text Available Excessive production of A? (amyloid ?-peptide has been shown to play an important role in the pathogenesis of AD (Alzheimer's disease. Although not yet well understood, aggregation of A? is known to cause toxicity to neurons. Our recent study demonstrated the ability for oligomeric A? to stimulate the production of ROS (reactive oxygen species in neurons through an NMDA (N-methyl-d-aspartate-dependent pathway. However, whether prolonged exposure of neurons to aggregated A? is associated with impairment of NMDA receptor function has not been extensively investigated. In the present study, we show that prolonged exposure of primary cortical neurons to A? oligomers caused mitochondrial dysfunction, an attenuation of NMDA receptor-mediated Ca2+ influx and inhibition of NMDA-induced AA (arachidonic acid release. Mitochondrial dysfunction and the decrease in NMDA receptor activity due to oligomeric A? are associated with an increase in ROS production. Gp91ds-tat, a specific peptide inhibitor of NADPH oxidase, and Mn(III-tetrakis(4-benzoic acid-porphyrin chloride, an ROS scavenger, effectively abrogated A?-induced ROS production. Furthermore, A?-induced mitochondrial dysfunction, impairment of NMDA Ca2+ influx and ROS production were prevented by pre-treatment of neurons with EGCG [(?-epigallocatechin-3-gallate], a major polyphenolic component of green tea. Taken together, these results support a role for NADPH oxidase-mediated ROS production in the cytotoxic effects of A?, and demonstrate the therapeutic potential of EGCG and other dietary polyphenols in delaying onset or retarding the progression of AD.

Grace Y Sun

2011-02-01

50

Palladium(II) complex induces apoptosis through ROS-mediated mitochondrial pathway in human lung adenocarcinoma cell line (A549)  

International Nuclear Information System (INIS)

Treatment for lung cancer is still far from satisfactory. Therefore, there is a call for novel anticancer agents. In the present study, the anticancer activity of (Pd(L)Cl), 1a complex towards A549 human lung adenocarcinoma cells was investigated. (Pd(L)Cl), 1a inhibited the growth of A549 cells in a time and dose-dependent manner. The IC50 value was 10?M after 24 h treatment. Flow cytometric analyses revealed a dose-related increase in the percentages of cells in the Sub-G0/G1 state, indicative of apoptosis which was further confirmed by Annexin V binding assay, via a ROS-mediated mitochondria-dependent pathway. Western blot analysis showed that 1a complex induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release, associated with the activation of caspase-3. All of these signal transduction pathways are involved in initiating apoptosis. (Pd(L)Cl), 1a seems to represent a potentially active drug against non-small cell lung cancer A549 cell line in vitro, and further studies in vivo are warranted. (author)

51

Curcumin Induced Human Gastric Cancer BGC-823 Cells Apoptosis by ROS-Mediated ASK1-MKK4-JNK Stress Signaling Pathway  

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Full Text Available The signaling mediated by stress-activated MAP kinases (MAPK, c-Jun N-terminal kinase (JNK has well-established importance in cancer. In the present report, we investigated the effects of curcumin on the signaling pathway in human gastric cancer BGC-823 cells. Curcumin induced reactive oxygen species (ROS production and BGC-823 cells apoptosis. Inhibition of ROS generation by antioxidant (NAC or Trion significantly prevented curcumin-mediated apoptosis. Notably, we observed that curcumin activated ASK1, a MAPKKK that is oxidative stress sensitive and responsible to phosphorylation of JNK via triggering cascades, up-regulated an upstream effector of the JNK, MKK4, and phosphorylated JNK protein expression in BGC-823 cells. However, curcumin induced ASK1-MKK4-JNK signaling was attenuated by NAC. All the findings confirm the possibility that oxidative stress-activated ASK1-MKK4-JNK signaling cascade promotes the apoptotic response in curcumin-treated BGC-823 cells.

Tao Liang

2014-09-01

52

A selenium-containing ruthenium complex as a cancer radiosensitizer, rational design and the important role of ROS-mediated signalling.  

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A novel selenium-containing ruthenium complex Ru(phtpy)(phenSe)Cl(ClO4) (phtpy = 4-phenyl-2,2':6',2''-terpyridine, phenSe = 2-selenicimidazole[4,5-f]1,10-phenanthroline) has been synthesized and found be able to enhance radiation-induced DNA damage through superoxide overproduction, which leads to G2/M arrest and apoptosis in cancer cells by activating ROS-mediated pathways. PMID:25574525

Deng, Zhiqin; Yu, Lianling; Cao, Wenqiang; Zheng, Wenjie; Chen, Tianfeng

2015-01-29

53

Toll-like receptor 4-mediated ROS signaling pathway involved in Ganoderma atrum polysaccharide-induced tumor necrosis factor-? secretion during macrophage activation.  

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Ganoderma atrum has been used as Chinese traditional medicine and healthful mushroom for thousands of years. The polysaccharide is regarded as the major bioactive substances in G. atrum. To delineate the underlying mechanism and signaling cascade involved in the immunomodulatory property of G. atrum polysaccharide (PSG-1). Specifically, this study is designed to examine the possibility of TLR4 as a candidate receptor interacted with G. atrum polysaccharide (PSG-1) and elucidate the role of reactive oxygen species (ROS) in PSG-1-induced tumor necrosis factor-? (TNF-?) production during macrophage activation. Flow cytometric and confocal laser-scanning microscopy analysis showed that fluorescence-labeled PSG-1 bind specifically to the macrophages. Moreover, PSG-1 stimulated TNF-? secretion of peritoneal macrophages from C3H/HeN mice, but not from C3H/HeJ mice. PSG-1-indcued TNF-? production was suppressed by anti-TLR4 mAb. Furthermore, ROS production was mediated by TLR4, and NADPH oxidase-derived ROS act as upstream of phosphoinositide 3-kinase(PI3K)/Akt/mitogen-activated protein kinases(MAPKs)/nuclear factor(NF)-?B signaling pathway in the regulation of PSG-1 stimulated TNF-? production. Taken together, we conclude that PSG-1 induces TNF-? secretion through TLR4/ROS/PI3K/Akt/MAPKs/NF-?B pathways during macrophage activation. Our findings provide a molecular basis for the potential of PSG-1 as a novel immunomodulatory agent. PMID:24447977

Yu, Qiang; Nie, Shao-Ping; Wang, Jun-Qiao; Yin, Peng-Fei; Huang, Dan-Fei; Li, Wen-Juan; Xie, Ming-Yong

2014-04-01

54

Resistance to ROS1 Inhibition Mediated by EGFR Pathway Activation in Non-Small Cell Lung Cancer  

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The targeting of oncogenic ‘driver’ kinases with small molecule inhibitors has proven to be a highly effective therapeutic strategy in selected non-small cell lung cancer (NSCLC) patients. However, acquired resistance to targeted therapies invariably arises and is a major limitation to patient care. ROS1 fusion proteins are a recently described class of oncogenic driver, and NSCLC patients that express these fusions generally respond well to ROS1-targeted therapy. In this study, we sought...

Davies, Kurtis D.; Mahale, Sakshi; Astling, David P.; Aisner, Dara L.; Le, Anh T.; Hinz, Trista K.; Vaishnavi, Aria; Bunn, Paul A.; Heasley, Lynn E.; Tan, Aik-choon; Camidge, D. Ross; Varella-garcia, Marileila; Doebele, Robert C.

2013-01-01

55

Inhibition of PGC-1? after chemotherapy-mediated insult confines multiple myeloma cell survival by affecting ROS accumulation.  

Science.gov (United States)

Peroxisome proliferator?activated receptor-? coactivator-1? (PGC-1?) is a key regulator of reactive oxygen species (ROS). However, whether it has the same role in multiple myeloma (MM), especially after treatement with chemotherapy, remains unclear. After treating cells with bortezomib or dexamethasone, the expression of PGC-1?, superoxide dismutase 2 (SOD-2) and catalase (CAT) was examined by RT-PCR. PGC-1? expression was also analyzed by western blotting. Small?interference RNA (siRNA) was applied to inhibit the expression of PGC-1? after chemotherapy. Changes of cellular ROS and apoptosis were detected by flow cytometric analysis. Cell proliferation was assessed by MTT assay. The expression of PGC-1? and SOD-2 following chemotherapy were upregulated, but accompanied by increased ROS. Following suppression of PGC-1?, ROS levels, as well as the pro-apoptotic effect of bortezomib were further increased. These findings suggested that PGC-1? regulates ROS in MM, and that inhibition of elevated PGC-1? following stimulation by chemotherapy leads to a higher level of ROS by downregulating antioxidant factors, eventually enhancing the antitumor effect of bortezomib. PMID:25434963

Cao, Dedong; Jin, Lu; Zhou, Hao; Yu, Wen; Hu, Yu; Guo, Tao

2015-02-01

56

Antifilarial effects of polyphenol rich ethanolic extract from the leaves of Azadirachta indica through molecular and biochemical approaches describing reactive oxygen species (ROS) mediated apoptosis of Setaria cervi.  

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Lymphatic filariasis, a global cause of morbidity needs much more attention in developing potent therapeutics that can be effective against both microfilariae (mf) and adults. Efficient botanicals that can induce apoptosis of filarial parasites possibly can provide a direction towards developing new class of antifilarials. In this work we have evaluated the antifilarial efficacy of an optimized polyphenol rich ethanolic extract of Azadirachta indica leaves (EEA). A. indica A. Juss has been widely used in the traditional Indian medicinal system 'Ayurveda' for the treatment of a variety of ailments. A thorough investigation towards biochemical and molecular mechanisms describing ROS mediated apoptosis in Setaria cervi was performed. Motility reduction, MTT reduction assay and dye exclusion test have confirmed the micro- and macrofilaricidal potential of EEA. Alterations were visible in mf and trichrome stained section of EEA-treated adult worms. We have found cellular disturbances in EEA-treated parasites characterized by chromatin condensation, in situ DNA fragmentation and nucleosomal DNA laddering. Depletion in worm GSH level and elevation in parasite GST, SOD, catalase, GPx and superoxide anion indicated the generation of ROS. Our results provided experimental evidence supporting that EEA causes a decreased expression of anti-apoptotic genes and increased pro-apoptotic gene expression at the level of both transcription and translation. Here we are reporting for the first time that antifilarial activity of EEA is mediated by ROS up regulation and apoptosis. PMID:24275557

Mukherjee, Niladri; Mukherjee, Suprabhat; Saini, Prasanta; Roy, Priya; Sinha Babu, Santi P

2014-01-01

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Loss of mitochondrial exo/endonuclease EXOG affects mitochondrial respiration and induces ROS-mediated cardiomyocyte hypertrophy.  

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Recently, a locus at the mitochondrial exo/endonuclease EXOG gene, which has been implicated in mitochondrial DNA repair, was associated with cardiac function. The function of EXOG in cardiomyocytes is still elusive. Here we investigated the role of EXOG in mitochondrial function and hypertrophy in cardiomyocytes. Depletion of EXOG in primary neonatal rat ventricular cardiomyocytes (NRVCs) induced a marked increase in cardiomyocyte hypertrophy. Depletion of EXOG, however, did not result in loss of mitochondrial DNA integrity. Although EXOG depletion did not induce fetal gene expression and common hypertrophy pathways were not activated, a clear increase in ribosomal S6 phosphorylation was observed, which readily explains increased protein synthesis. With the use of a Seahorse flux analyzer, it was shown that the mitochondrial oxidative consumption rate (OCR) was increased 2.4-fold in EXOG-depleted NRVCs. Moreover, ATP-linked OCR was 5.2-fold higher. This increase was not explained by mitochondrial biogenesis or alterations in mitochondrial membrane potential. Western blotting confirmed normal levels of the oxidative phosphorylation (OXPHOS) complexes. The increased OCR was accompanied by a 5.4-fold increase in mitochondrial ROS levels. These increased ROS levels could be normalized with specific mitochondrial ROS scavengers (MitoTEMPO, mnSOD). Remarkably, scavenging of excess ROS strongly attenuated the hypertrophic response. In conclusion, loss of EXOG affects normal mitochondrial function resulting in increased mitochondrial respiration, excess ROS production, and cardiomyocyte hypertrophy. PMID:25377088

Tigchelaar, Wardit; Yu, Hongjuan; de Jong, Anne Margreet; van Gilst, Wiek H; van der Harst, Pim; Westenbrink, B Daan; de Boer, Rudolf A; Silljé, Herman H W

2015-01-15

58

ROS-dependent Syk and Pyk2-mediated STAT1 activation is required for 15(S)-hydroxyeicosatetraenoic acid-induced CD36 expression and foam cell formation.  

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15(S)-Hydroxyeicosatetraenoic acid (15(S)-HETE), the major 15-lipoxygenase 1/2 (15-LO1/2) metabolite of arachidonic acid (AA), induces CD36 expression through xanthine oxidase and NADPH oxidase-dependent ROS production and Syk and Pyk2-dependent STAT1 activation. In line with these observations, 15(S)-HETE also induced foam cell formation involving ROS, Syk, Pyk2, and STAT1-mediated CD36 expression. In addition, peritoneal macrophages from Western diet-fed ApoE(-/-) mice exhibited elevated levels of xanthine oxidase and NADPH oxidase activities, ROS production, Syk, Pyk2, and STAT1 phosphorylation, and CD36 expression compared to those from ApoE(-/-):12/15-LO(-/-) mice and these events correlated with increased lipid deposits, macrophage content, and lesion progression in the aortic roots. Human atherosclerotic arteries also showed increased 15-LO1 expression, STAT1 phosphorylation, and CD36 levels as compared to normal arteries. Together, these findings suggest that 12/15-LO metabolites of AA, particularly 12/15(S)-HETE, might play a crucial role in atherogenesis by enhancing foam cell formation. PMID:25152235

Kotla, Sivareddy; Singh, Nikhlesh K; Traylor, James G; Orr, A Wayne; Rao, Gadiparthi N

2014-11-01

59

Oleanolic acid arrests cell cycle and induces apoptosis via ROS-mediated mitochondrial depolarization and lysosomal membrane permeabilization in human pancreatic cancer cells.  

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Oleanolic acid (OA), a pentacyclic triterpenoid, exhibits potential anti-tumor activity against many tumor cell lines. This study aims to examine the anti-tumor activity of OA on pancreatic cancer cells and its potential molecular mechanism. The results showed that the proliferation of Panc-28 cells was inhibited by OA in a concentration-dependent manner, with an IC50 (The half maximal inhibitory concentration) value of 46.35?µg ml(-1) , as determined by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The cell cycle was arrested in S phase and G2/M phase by OA. The study also showed that OA could induce remarkable apoptosis, evidenced by an increased percentage of early/late apoptotic cells, DNA ladder and nuclear morphology change. Further study revealed that OA could induce Reactive Oxygen Species (ROS) generation, mitochondrial depolarization, release of cytochrome C, lysosomal membrane permeabilization and leakage of cathepin B. The expression of apoptosis-correlated proteins was also affected in cells treated with OA, including activation of caspases-3/9 and cleavage of PARP. Further study confirmed that ROS scavenger vitamin C could reverse the apoptosis induced by OA in Panc-28 cells. Our results provide evidence that OA arrests the cell cycle and induces apoptosis, possibly via ROS-mediated mitochondrial and a lysosomal pathway in Panc-28 cells. PMID:22678527

Wei, Jianteng; Liu, Ming; Liu, Haizhou; Wang, Hui; Wang, Fengxia; Zhang, Yuyan; Han, Lijun; Lin, Xiukun

2013-08-01

60

Snake venom toxin from vipera lebetina turanica induces apoptosis of colon cancer cells via upregulation of ROS- and JNK-mediated death receptor expression  

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Full Text Available Abstract Background Abundant research suggested that the cancer cells avoid destruction by the immune system through down-regulation or mutation of death receptors. Therefore, it is very important that finding the agents that increase the death receptors of cancer cells. In this study, we demonstrated that the snake venom toxin from Vipera lebetina turanica induce the apoptosis of colon cancer cells through reactive oxygen species (ROS and c-Jun N-terminal kinases (JNK dependent death receptor (DR4 and DR5 expression. Methods We used cell viability assays, DAPI/TUNEL assays, as well as western blot for detection of apoptosis related proteins and DRs to demonstrate that snake venom toxin-induced apoptosis is DR4 and DR5 dependent. We carried out transient siRNA knockdowns of DR4 and DR5 in colon cancer cells. Results We showed that snake venom toxin inhibited growth of colon cancer cells through induction of apoptosis. We also showed that the expression of DR4 and DR5 was increased by treatment of snake venom toxin. Moreover, knockdown of DR4 or DR5 reversed the effect of snake venom toxin. Snake venom toxin also induced JNK phosphorylation and ROS generation, however, pretreatment of JNK inhibitor and ROS scavenger reversed the inhibitory effect of snake venom toxin on cancer cell proliferation, and reduced the snake venom toxin-induced upregulation of DR4 and DR5 expression. Conclusions Our results indicated that snake venom toxin could inhibit human colon cancer cell growth, and these effects may be related to ROS and JNK mediated activation of death receptor (DR4 and DR5 signals.

Park Mi

2012-06-01

 
 
 
 
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Loss of Intralipid®- but Not Sevoflurane-Mediated Cardioprotection in Early Type-2 Diabetic Hearts of Fructose-Fed Rats: Importance of ROS Signaling  

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Background Insulin resistance and early type-2 diabetes are highly prevalent. However, it is unknown whether Intralipid® and sevoflurane protect the early diabetic heart against ischemia-reperfusion injury. Methods Early type-2 diabetic hearts from Sprague-Dawley rats fed for 6 weeks with fructose were exposed to 15 min of ischemia and 30 min of reperfusion. Intralipid® (1%) was administered at the onset of reperfusion. Peri-ischemic sevoflurane (2 vol.-%) served as alternative protection strategy. Recovery of left ventricular function was recorded and the activation of Akt and ERK 1/2 was monitored. Mitochondrial function was assessed by high-resolution respirometry and mitochondrial ROS production was measured by Amplex Red and aconitase activity assays. Acylcarnitine tissue content was measured and concentration-response curves of complex IV inhibition by palmitoylcarnitine were obtained. Results Intralipid® did not exert protection in early diabetic hearts, while sevoflurane improved functional recovery. Sevoflurane protection was abolished by concomitant administration of the ROS scavenger N-2-mercaptopropionyl glycine. Sevoflurane, but not Intralipid® produced protective ROS during reperfusion, which activated Akt. Intralipid® failed to inhibit respiratory complex IV, while sevoflurane inhibited complex I. Early diabetic hearts exhibited reduced carnitine-palmitoyl-transferase-1 activity, but palmitoylcarnitine could not rescue protection and enhance postischemic functional recovery. Cardiac mitochondria from early diabetic rats exhibited an increased content of subunit IV-2 of respiratory complex IV and of uncoupling protein-3. Conclusions Early type-2 diabetic hearts lose complex IV-mediated protection by Intralipid® potentially due to a switch in complex IV subunit expression and increased mitochondrial uncoupling, but are amenable to complex I-mediated sevoflurane protection. PMID:25127027

Zhang, Liyan; Affolter, Andreas; Gandhi, Manoj; Hersberger, Martin; Warren, Blair E.; Lemieux, Hélène; Sobhi, Hany F.; Clanachan, Alexander S.; Zaugg, Michael

2014-01-01

62

Chamaejasmine Induces Apoptosis in Human Lung Adenocarcinoma A549 Cells through a Ros-Mediated Mitochondrial Pathway  

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In the present study, the anticancer activity of chamaejasmine towards A549 human lung adenocarcinoma cells was investigated. In order to explore the underlying mechanism of cell growth inhibition of chamaejasmine, cell cycle distribution, ROS generation, mitochondrial membrane potential (??m) disruption, and expression of cytochrome c, Bax, Bcl-2, caspase-3, caspase-9 and PARP were measured in A549 cells. Chamaejasmine inhibited the growth of A549 cells in a time and dose-dependent manner....

Lina Xing; Xiangying Xu; Rongwei Guan; Guanglu Dong; Li Cai; Songliu Hu; Yuanyuan Qu; Hongyang Yu; Tingting Zhang

2011-01-01

63

PKC? phosphorylation is an upstream event of GSK3 inactivation-mediated ROS generation in TGF-?1-induced senescence.  

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Transforming growth factor ?1 (TGF-?1) induces Mv1Lu cell senescence through inactivating glycogen synthase kinase 3 (GSK3), thereby inactivating complex IV and increasing intracellular ROS. In the present study, we identified protein kinase C delta (PKC?) as an upstream regulator of GSK3 inactivation in this mechanism of TGF-?1-induced senescence. When Mv1Lu cells were exposed to TGF-?1, PKC? phosphorylation simultaneously increased with GSK3 phosphorylation, and then AKT and ERK were phosphorylated. AKT phosphorylation and Smad signaling were independent of GSK3 phosphorylation, but ERK phosphorylation was downstream of GSK3 inactivation. TGF-?1-triggered GSK3 phosphorylation was blocked by inhibition of PKC?, using its pharmacological inhibitor, Rottlerin, or overexpression of a dominant negative PKC? mutant, but GSK3 inhibition with SB415286 did not alter PKC? phosphorylation. Activation of PKC? by PMA delayed cell growth and increased intracellular ROS level, but did not induce senescent phenotypes. In addition, overexpression of wild type or a constitutively active PKC? mutant was enough to delay cell growth and decrease the mitochondrial oxygen consumption rate and complex IV activity, but weakly induce senescence. However, PMA treatment on Mv1Lu cells, which overexpress wild type and constitutively active PKC? mutants, effectively induced senescence. These results indicate that PKC? plays a key role in TGF-?1-induced senescence of Mv1Lu cells through the phosphorylation of GSK3, thereby triggering mitochondrial complex IV dysfunction and intracellular ROS generation. PMID:24917460

Byun, H-O; Jung, H-J; Kim, M-J; Yoon, G

2014-09-01

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TRPV1 mediates cell death in rat synovial fibroblasts through calcium entry-dependent ROS production and mitochondrial depolarization  

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Synoviocyte hyperplasia is critical for rheumatoid arthritis, therefore, potentially an important target for therapeutics. It was found in this work that a TRPV1 agonist capsaicin, and acidic solution (pH 5.5) induced increases in cytosolic calcium concentration ([Ca2+]c) and reactive oxygen species (ROS) production in synoviocytes isolated from a rat model of collagen-induced arthritis. The increases in both [Ca2+]c and ROS production were completely abolished in calcium-free buffer or by a TRPV1 antagonist capsazepine. Further experiments revealed that capsaicin and pH 5.5 solution caused mitochondrial membrane depolarization and reduction in cell viability; such effects were inhibited by capsazepine, or the NAD(P)H oxidase inhibitor diphenylene iodonium. Both capsaicin and pH 5.5 buffer induced apoptosis as shown by nuclear condensation and fragmentation. Furthermore, RT-PCR readily detected TRPV1 mRNA expression in the isolated synoviocytes. Taken together, these data indicated that TRPV1 activation triggered synoviocyte death by [Ca2+]c elevation, ROS production, and mitochondrial membrane depolarization

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?-Lipoic acid protected cardiomyoblasts from the injury induced by sodium nitroprusside through ROS-mediated Akt/Gsk-3? activation.  

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It has been long noted that cardiac cell apoptosis provoked by excessive production of nitric oxide (NO) plays important roles in the pathogenesis of variant cardiac diseases. Attenuation of NO-induced injury would be an alternative therapeutic approach for the development of cardiac disorders. This study investigated the effects of ?-lipoic acid (LA) on the injury induced by sodium nitroprusside (SNP), a widely used NO donor, in rat cardiomyoblast H9c2 cells. SNP challenge significantly decreased cell viability and increased apoptosis, as evidenced by morphological abnormalities, nuclear condensation and decline of mitochondrial potential (??m). These changes induced by SNP were significantly attenuated by LA pretreatment. Furthermore, LA pretreatment prevented the SNP-triggered suppression of Akt and Gsk-3? activation. Blockade of Akt activation with triciribin (API) completely abolished the cytoprotection of LA against SNP challenge. In addition, LA moderately increased intracellular ROS production. Interestingly, inhibition of ROS with N-acetylcysteine abrogated Akt/Gsk-3? activation and the LA-induced cytoprotection following SNP stimulation. Taken together, the results indicate that LA protected the SNP-induced injury in cardiac H9c2 cells through, at least in part, the activation of Akt/Gsk-3? signaling in a ROS-dependent mechanism. PMID:25193743

Jiang, Surong; Zhu, Weina; Wu, Jun; Li, Chuanfu; Zhang, Xiaojin; Li, Yuehua; Cao, Kejiang; Liu, Li

2014-12-01

66

A small library of synthetic di-substituted 1, 4-naphthoquinones induces ROS-mediated cell death in murine fibroblasts.  

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Synthesis of compound libraries and their concurrent assessment as selective reagents for probing and modulating biological function continues to be an active area of chemical biology. Microwave-assisted solid-phase Dötz benzannulation reactions have been used to inexpensively synthesize 2, 3-disubstituted-1, 4-naphthoquinone derivatives. Herein, we report the biological testing of a small library of such compounds using a murine fibroblast cell line (L929). Assessment of cellular viability identified three categories of cytotoxic compounds: no toxicity, low/intermediate toxicity and high toxicity. Increased levels of Annexin-V-positive staining and of caspase 3 activity confirmed that low, intermediate, and highly toxic compounds promote cell death. The compounds varied in their ability to induce mitochondrial depolarization and formation of reactive oxygen species (ROS). Both cytotoxic and non-cytotoxic compounds triggered mitochondrial depolarization, while one highly cytotoxic compound did not. In addition, all cytotoxic compounds promoted increased intracellular ROS but the cells were only partially protected from compound-induced apoptosis when in the presence of superoxide dismutase, catalase, or ascorbic acid suggesting utilization of additional pro-death mechanisms. In summary, nine of twelve (75%) 1, 4-naphthoquinone synthetic compounds were cytotoxic. Although the mitochondria did not appear to be a central target for induction of cell death, all of the cytotoxic compounds induced ROS formation. Thus, the data demonstrate that the synthesis regime effectively created cytotoxic compounds highlighting the potential use of the regime and its products for the identification of biologically relevant reagents. PMID:25197824

Ramirez, Oscar; Motta-Mena, Laura B; Cordova, Amanda; Garza, Kristine M

2014-01-01

67

Induction of Apoptosis by Costunolide in Bladder Cancer Cells is Mediated through ROS Generation and Mitochondrial Dysfunction  

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Full Text Available Despite the availability of several therapeutic options, a safer and more effective modality is urgently needed for treatment of bladder cancer. Costunolide, a member of sesquiterpene lactone family, possesses potent anticancer properties. In this study, for the first time we investigated the effects of costunolide on the cell viability and apoptosis in human bladder cancer T24 cells. Treatment of T24 cells with costunolide resulted in a dose-dependent inhibition of cell viability and induction of apoptosis which was associated with the generation of ROS and disruption of mitochondrial membrane potential (??m. These effects were significantly blocked when the cells were pretreated with N-acetyl- cysteine (NAC, a specific ROS inhibitor. Exposure of T24 cells to costunolide was also associated with increased expression of Bax, down-regulation of Bcl-2, survivin and significant activation of caspase-3, and its downstream target PARP. These findings provide the rationale for further in vivo and clinical investigation of costunolide against human bladder cancer.

Ichiro Tsuji

2013-01-01

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Fucoidan Derived from Undaria pinnatifida Induces Apoptosis in Human Hepatocellular Carcinoma SMMC-7721 Cells via the ROS-Mediated Mitochondrial Pathway  

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Full Text Available Fucoidans, fucose-enriched sulfated polysaccharides isolated from brown algae and marine invertebrates, have been shown to exert anticancer activity in several types of human cancer, including leukemia and breast cancer and in lung adenocarcinoma cells. In the present study, the anticancer activity of the fucoidan extracted from the brown seaweed Undaria pinnatifida was investigated in human hepatocellular carcinoma SMMC-7721 cells, and the underlying mechanisms of action were investigated. SMMC-7721 cells exposed to fucoidan displayed growth inhibition and several typical features of apoptotic cells, such as chromatin condensation and marginalization, a decrease in the number of mitochondria, and in mitochondrial swelling and vacuolation. Fucoidan-induced cell death was associated with depletion of reduced glutathione (GSH, accumulation of high intracellular levels of reactive oxygen species (ROS, and accompanied by damage to the mitochondrial ultrastructure, depolarization of the mitochondrial membrane potential (MMP, ??m and caspase activation. Moreover, fucoidan led to altered expression of factors related to apoptosis, including downregulating Livin and XIAP mRNA, which are members of the inhibitor of apoptotic protein (IAP family, and increased the Bax-to-Bcl-2 ratio. These findings suggest that fucoidan isolated from U. pinnatifida induced apoptosis in SMMC-7721 cells via the ROS-mediated mitochondrial pathway.

Lin Hou

2013-06-01

69

Fucoidan Derived from Undaria pinnatifida Induces Apoptosis in Human Hepatocellular Carcinoma SMMC-7721 Cells via the ROS-Mediated Mitochondrial Pathway  

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Fucoidans, fucose-enriched sulfated polysaccharides isolated from brown algae and marine invertebrates, have been shown to exert anticancer activity in several types of human cancer, including leukemia and breast cancer and in lung adenocarcinoma cells. In the present study, the anticancer activity of the fucoidan extracted from the brown seaweed Undaria pinnatifida was investigated in human hepatocellular carcinoma SMMC-7721 cells, and the underlying mechanisms of action were investigated. SMMC-7721 cells exposed to fucoidan displayed growth inhibition and several typical features of apoptotic cells, such as chromatin condensation and marginalization, a decrease in the number of mitochondria, and in mitochondrial swelling and vacuolation. Fucoidan-induced cell death was associated with depletion of reduced glutathione (GSH), accumulation of high intracellular levels of reactive oxygen species (ROS), and accompanied by damage to the mitochondrial ultrastructure, depolarization of the mitochondrial membrane potential (MMP, ??m) and caspase activation. Moreover, fucoidan led to altered expression of factors related to apoptosis, including downregulating Livin and XIAP mRNA, which are members of the inhibitor of apoptotic protein (IAP) family, and increased the Bax-to-Bcl-2 ratio. These findings suggest that fucoidan isolated from U. pinnatifida induced apoptosis in SMMC-7721 cells via the ROS-mediated mitochondrial pathway. PMID:23752353

Yang, Lili; Wang, Peisheng; Wang, Huaxin; Li, Qiaomei; Teng, Hongming; Liu, Zhichao; Yang, Wenbo; Hou, Lin; Zou, Xiangyang

2013-01-01

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The role of NOS-mediated ROS accumulation in an early phase Cu-induced acute cytotoxicity in MCF-7 cells.  

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Copper (Cu) ion is essential for the biological systems, however, high level of CuCl2 exposure causes detrimental effects, which leads to cell apoptosis. Nitric oxide (NO) is an efficient cell signal messenger, which plays an important role in cell apoptosis. However, the potential mechanism of an early phase Cu-induced acute cytotoxicity through the nitric oxide synthase (NOS) signaling pathway and its interaction has not been studied. In this report, we provide data showing that high level of CuCl2 could rapidly decrease the NO production with the release of Ca(2+) and Zn(2+), and then modulate the transcriptional and translational expression of NOSs in MCF-7 cells. The reactive oxygen species (ROS) level in cells was increased after high level of CuCl2 exposure, which led to the alpha subunit of eukaryotic initiation factor 2 phosphorylation. By using the free radical scavenger N-acetyl-L-cysteine or the NOS substrate L-arginine, it demonstrated that NOS played a critical role on the Cu-induced ROS generation, which further led to the oxidative stress and cell apoptosis. These results suggested that Cu-induced apoptosis was associated with the oxidative stress, and through the NOS-mediated signaling pathway. PMID:25403658

Zhong, Lingying; Wang, Lumei; Xu, Lurong; Liu, Qunlu; Jiang, Linlei; Zhi, Yuee; Lu, Wei; Zhou, Pei

2015-02-01

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A rapid and transient ROS generation by cadmium triggers apoptosis via caspase-dependent pathway in HepG2 cells and this is inhibited through N-acetylcysteine-mediated catalase upregulation  

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Although reactive oxygen species (ROS) have been implicated in cadmium (Cd)-induced hepatotoxicity, the role of ROS in this pathway remains unclear. Therefore, we attempted to determine the molecular mechanisms relevant to Cd-induced cell death in HepG2 cells. Cd was found to induce apoptosis in the HepG2 cells in a time- and dose-dependent fashion, as confirmed by DNA fragmentation analysis and TUNEL staining. In the early stages, both rapid and transient ROS generation triggered apoptosis via Fas activation and subsequent caspase-8-dependent Bid cleavage, as well as by calpain-mediated mitochondrial Bax cleavage. The timing of Bid activation was coincided with the timing at which the mitochondrial transmembrane potential (MMP) collapsed as well as the cytochrome c (Cyt c) released into the cytosol. Furthermore, mitochondrial permeability transition (MPT) pore inhibitors, such as cyclosporin A (CsA) and bongkrekic acid (BA), did not block Cd-induced ROS generation, MMP collapse and Cyt c release. N-acetylcysteine (NAC) pretreatment resulted in the complete inhibition of the Cd-induced apoptosis via catalase upregulation and subsequent Fas downregulation. NAC treatment also completely blocked the Cd-induced intracellular ROS generation, MMP collapse and Cyt c release, indicating that Cd-induced mitochondrial dysfunction may be regulated indirectly by ROS-mediated signaling pathway. Taken together, a rapid and transient ROS generation by Cd triggers apoptosis via caspaeration by Cd triggers apoptosis via caspase-dependent pathway and subsequent mitochondrial pathway. NAC inhibits Cd-induced apoptosis through the blocking of ROS generation as well as the catalase upregulation

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Quinazoline analog HMJ-30 inhibits angiogenesis: involvement of endothelial cell apoptosis through ROS-JNK-mediated death receptor 5 signaling.  

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The aim of the present study was to explore the effect of 6-fluoro-2-(3-fluorophenyl)-4-(cyanoanilino) quinazoline (HMJ-30) on the anti-angiogenic properties and apoptosis-related mechanism of human umbilical vein endothelial cells (HUVECs). In this study, HMJ-30 dose- and time-dependently inhibited the viability of HUVECs. We also found that HMJ-30 enhanced disruption of tube-like structures and suppressed cell migration in HUVECs after vascular endothelial growth factor (VEGF) induction. HMJ-30 was also observed to inhibit vessel branching and sprouting in chicken chorioallantoic membrane (CAM). Microsprouting induced by VEGF in the rat aortic ring and blood vessel formation in a mouse Matrigel plug were individually suppressed by HMJ-30. In an in vitro study, HMJ-30 induced the apoptotic death of HUVECs as indicated by DNA fragmentation and promoted reactive oxygen species (ROS) production as determined by flow cytometric assay. In addition, extrinsic caspase signaling (caspase-8 and -3) was activated in the HMJ-30-treated HUVECs and their inhibitors were applied to assess the signal transduction. We investigated the upstream of the death receptor pathway and further observed that the levels of death receptor 5 (DR5) and phosphorylated c-Jun N-terminal kinase (JNK) signals were upregulated in HUVECs following HMJ-30 challenge, which was confirmed by a JNK-specific inhibitor (SP600125). Hence, HMJ-30-induced endothelial cell apoptosis involved the ROS/JNK-regulated DR5 pathway. In summary, HMJ-30 may provide a potential therapeutic effect for the anti-vascular targeting of angiogenesis during cancer treatment. PMID:24919794

Lu, Chi-Cheng; Chen, Hao-Ping; Chiang, Jo-Hua; Jin, Yi-An; Kuo, Sheng-Chu; Wu, Tian-Shung; Hour, Mann-Jen; Yang, Jai-Sing; Chiu, Yu-Jen

2014-08-01

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SFE-CO2 Extract from Typhonium giganteum Engl. Tubers, Induces Apoptosis in Human Hepatoma SMMC-7721 Cells Involvement of a ROS-Mediated Mitochondrial Pathway  

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Full Text Available Typhonium giganteum Engl. (BaiFuzi is one of the herbs commonly used in traditional Chinese medicine against cancer. In our previous studies, 37 compounds were identified the SFE-CO2 (supercritical fluid extraction with CO2 extract by GC-MS, including the four major components [?-sitosterol (40.22%, campesterol (18.45%, n-hexadecanoic acid (9.52% and (Z,Z-9,12-octadecadienoic acid (8.15%]. The anti-cancer mechanisms of the SFE-CO2 extract from T. giganteum Engl. tubers have not been reported as yet. In this paper, the molecular mechanisms of the SFE-CO2 extract-mediated apoptosis in SMMC-7721 cells were further examined. SFE-CO2 extract inhibited the growth of SMMC-7721 cells in a time- and dose-dependent manner, arrested the cell cycle in the S phase and G2/M phase, and induced apoptosis. In addition, reactive oxygen species (ROS increase, reduction of mitochondrial membrane potential, a rise in intracellular calcium levels were found in SMMC-7721 cells after treated with the extract. Western blot analysis showed that the extract caused down-regulation of Bcl-2 expression, and up-regulation of Bax expression. Moreover, caspase-3 and caspase-9 protease activity significantly increased in a dose-dependent manner. Collectively, our results showed that the SFE-CO2 extract from T. giganteum Engl. tubers induces apoptosis in SMMC-7721 cells involving a ROS-mediated mitochondrial signalling pathway.

Li Zhang

2011-09-01

74

Induction of Nrf2-mediated genes by Antrodia salmonea inhibits ROS generation and inflammatory effects in lipopolysaccharide-stimulated RAW264.7 macrophages.  

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Antrodia salmonea (AS), a well-known medicinal mushroom in Taiwan, has been reported to exhibit anti-oxidant, anti-angiogenic, anti-atherogenic, and anti-inflammatory effects. In the present study, we investigated the activation of Nrf2-mediated antioxidant genes in RAW264.7 macrophages by the fermented culture broth of AS, studied the resulting protection against lipopolysaccharide (LPS)-stimulated inflammation, and revealed the molecular mechanisms underlying these protective effects. We found that non-cytotoxic concentrations of AS (25-100 ?g mL(-1)) protected macrophages from LPS-induced cell death and ROS generation in a dose-dependent manner. The antioxidant potential of AS was directly correlated with the increased expression of the antioxidant genes HO-1, NQO-1, and ?-GCLC, as well as the level of intracellular GSH followed by an increase in the nuclear translocation and transcriptional activation of the Nrf2-ARE pathway. Furthermore, Nrf2 knockdown diminished the protective effects of AS, as evidenced by the increased production of pro-inflammatory cytokines and chemokines, including PGE2, NO, TNF-?, and IL-1?, in LPS-stimulated macrophages. Notably, AS treatment significantly inhibited LPS-induced ICAM-1 expression in macrophages. Our data suggest that the anti-inflammatory potential of Antrodia salmonea is mediated by the activation of Nrf2-dependent antioxidant defense mechanisms. Results support the traditional usage of this beneficial mushroom for the treatment of free radical-related diseases and inflammation. PMID:25380370

Yang, Hsin-Ling; Lin, Shu-Wei; Lee, Chuan-Chen; Lin, Kai-Yuan; Liao, Chun-Huei; Yang, Ting-Yu; Wang, Hui-Min; Huang, Hui-Chi; Wu, Chi-Rei; Hseu, You-Cheng

2015-01-24

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PKC? and ? Possibly Mediate FSH-Induced Mouse Oocyte Maturation via NOX-ROS-TACE Cascade Signaling Pathway  

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In mammals, gonadotropins stimulate oocyte maturation via the epidermal growth factor (EGF) network, and the protein kinase C (PKC) signaling pathway mediates this process. Tumor necrosis factor-? converting enzyme (TACE) is an important protein responding to PKC activation. However, the detailed signaling cascade between PKC and TACE in follicle-stimulating hormone (FSH)-induced oocyte maturation in vitro remains unclear. In this study, we found that rottlerin (mallotoxin, MTX), the inhibit...

Chen, Qian; Zhang, Wenqiang; Ran, Hao; Feng, Lizhao; Yan, Hao; Mu, Xinyi; Han, Yingying; Liu, Wei; Xia, Guoliang; Wang, Chao

2014-01-01

76

ROS accumulation and IGF-IR inhibition contribute to fenofibrate/PPAR? -mediated inhibition of Glioma cell motility in vitro  

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Abstract Background Glioblastomas are characterized by rapid cell growth, aggressive CNS infiltration, and are resistant to all known anticancer regimens. Recent studies indicate that fibrates and statins possess anticancer potential. Fenofibrate is a potent agonist of peroxisome proliferator activated receptor alpha (PPAR?) that can switch energy metabolism from glycolysis to fatty acid ?-oxidation, and has low systemic toxicity. Fenofibrate also attenuates IGF-I-mediated ...

Del Valle Luis; Wybieralska Ewa; Grabacka Maja; Wilk Anna; Urbanska Katarzyna; Drukala Justyna; Madeja Zbigniew; Reiss Krzysztof

2010-01-01

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Arsenic trioxide sensitizes CD95/Fas-induced apoptosis through ROS-mediated upregulation of CD95/Fas by NF-kappaB activation.  

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CD95/Fas is a cell surface protein that belongs to the tumor necrosis factor receptor family. Signals through CD95/Fas are able to induce apoptosis in sensitive cells. Therefore, modalities to regulate the CD95/Fas expression level in tumor cells are called for. In the present study, we show that sublethal doses of arsenic trioxide (As2O3) sensitized CD95/Fas-induced apoptosis in human cervical cancer cells, and the sensitizing effects resulted from As2O3-mediated increase in the expression of the CD95/Fas. N-acetyl-L-cysteine, a specific scavenger of reactive oxygen species, abrogated As2O3-induced upregulation of CD95/Fas and enhancement of CD95/Fas-mediated apoptosis. Furthermore, inhibition of NF-kappaB by transient transfection of IkappaBalpha supersurppessor blocked the increase of CD95/Fas expression following As2O2 treatment. Antisense oligonucleotide of CD95/Fas and ZB4, an antibody that blocks the binding of CD95/Fas ligand to CD95/Fas, reduced the amount of As2O3-sensitized CD95/Fas-induced apoptosis, demonstrating the specificity of CD95/Fas-binding ligands in the As2O3-sensitized CD95/Fas-induced apoptosis. These findings demonstrate that sensitization of human cervical cancer cells to CD95/Fas-mediated apoptosis by As2O3 can be partly due to induction of ROS and subsequent upregulation of CD95/Fas gene expression by NF-kappaB activation. PMID:15382040

Woo, Sang Hyeok; Park, In-Chul; Park, Myung-Jin; An, Sungkwan; Lee, Hyung-Chahn; Jin, Hyeon-Ok; Park, Sin-Ae; Cho, Hyeyoung; Lee, Su-Jae; Gwak, Ho-Shin; Hong, Young-Joon; Hong, Seok-Il; Rhee, Chang Hun

2004-11-20

78

(?)-Epigallocatechin-3-Gallate Induces Non-Apoptotic Cell Death in Human Cancer Cells via ROS-Mediated Lysosomal Membrane Permeabilization  

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(?)-Epigallocatechin-3-gallate (EGCG) is the most extensive studied tea polyphenol for its anti-cancer function. In this study, we report a novel mechanism of action for EGCG-mediated cell death by identifying the critical role of lysosomal membrane permeabilization (LMP). First, EGCG-induced cell death in human cancer cells (both HepG2 and HeLa) was found to be caspase-independent and accompanied by evident cytosolic vacuolization, only observable when cells were treated in serum-free medi...

Zhang, Yin; Yang, Nai-di; Zhou, Fan; Shen, Ting; Duan, Ting; Zhou, Jing; Shi, Yin; Zhu, Xin-qiang; Shen, Han-ming

2012-01-01

79

A novel androstenedione derivative induces ROS-mediated autophagy and attenuates drug resistance in osteosarcoma by inhibiting macrophage migration inhibitory factor (MIF).  

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Osteosarcoma is a common primary bone tumor in children and adolescents. The drug resistance of osteosarcoma leads to high lethality. Macrophage migration inhibitory factor (MIF) is an inflammation-related cytokine implicated in the chemoresistance of breast cancer. In this study, we isolated a novel androstenedione derivative identified as 3,4-dihydroxy-9,10-secoandrosta-1,3,5,7-tetraene-9,17-dione (DSTD). DSTD could inhibit MIF expression in MG-63 and U2OS cells. The inhibition of MIF by DSTD promoted autophagy by inducing Bcl-2 downregulation and the translocation of HMGB1. N-acetyl-L-cysteine (NAC) and 3-methyladenine (3-MA) attenuated DSTD-induced autophagy but promoted cell death, suggesting that DSTD induced ROS-mediated autophagy to rescue cell death. However, in the presence of chemotherapy drugs, DSTD enhanced the chemosensitivity by decreasing the HMGB1 level. Our data suggest MIF inhibition as a therapeutic strategy for overcoming drug resistance in osteosarcoma. PMID:25101674

Liu, Y; Zhao, L; Ju, Y; Li, W; Zhang, M; Jiao, Y; Zhang, J; Wang, S; Wang, Y; Zhao, M; Zhang, B; Zhao, Y

2014-01-01

80

Chaetocin-induced ROS-mediated apoptosis involves ATM-YAP1 axis and JNK-dependent inhibition of glucose metabolism.  

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Oxidative stress serves as an important regulator of both apoptosis and metabolic reprogramming in tumor cells. Chaetocin, a histone methyltransferase inhibitor, is known to induce ROS generation. As elevating basal ROS level sensitizes glioma cells to apoptosis, the ability of Chaetocin in regulating apoptotic and metabolic adaptive responses in glioma was investigated. Chaetocin induced glioma cell apoptosis in a ROS-dependent manner. Increased intracellular ROS induced (i) Yes-associated protein 1 (YAP1) expression independent of the canonical Hippo pathway as well as (ii) ATM and JNK activation. Increased interaction of YAP1 with p73 and p300 induced apoptosis in an ATM-dependent manner. Chaetocin induced JNK modulated several metabolic parameters like glucose uptake, lactate production, ATP generation, and activity of glycolytic enzymes hexokinase and pyruvate kinase. However, JNK had no effect on ATM or YAP1 expression. Coherent with the in vitro findings, Chaetocin reduced tumor burden in heterotypic xenograft glioma mouse model. Chaetocin-treated tumors exhibited heightened ROS, pATM, YAP1 and pJNK levels. Our study highlights the coordinated control of glioma cell proliferation and metabolism by ROS through (i) ATM-YAP1-driven apoptotic pathway and (ii) JNK-regulated metabolic adaptation. The elucidation of these newfound connections and the roles played by ROS to simultaneously shift metabolic program and induce apoptosis could provide insights toward the development of new anti-glioma strategies. PMID:24810048

Dixit, D; Ghildiyal, R; Anto, N P; Sen, E

2014-01-01

 
 
 
 
81

Chaetocin-induced ROS-mediated apoptosis involves ATM–YAP1 axis and JNK-dependent inhibition of glucose metabolism  

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Oxidative stress serves as an important regulator of both apoptosis and metabolic reprogramming in tumor cells. Chaetocin, a histone methyltransferase inhibitor, is known to induce ROS generation. As elevating basal ROS level sensitizes glioma cells to apoptosis, the ability of Chaetocin in regulating apoptotic and metabolic adaptive responses in glioma was investigated. Chaetocin induced glioma cell apoptosis in a ROS-dependent manner. Increased intracellular ROS induced (i) Yes-associated protein 1 (YAP1) expression independent of the canonical Hippo pathway as well as (ii) ATM and JNK activation. Increased interaction of YAP1 with p73 and p300 induced apoptosis in an ATM-dependent manner. Chaetocin induced JNK modulated several metabolic parameters like glucose uptake, lactate production, ATP generation, and activity of glycolytic enzymes hexokinase and pyruvate kinase. However, JNK had no effect on ATM or YAP1 expression. Coherent with the in vitro findings, Chaetocin reduced tumor burden in heterotypic xenograft glioma mouse model. Chaetocin-treated tumors exhibited heightened ROS, pATM, YAP1 and pJNK levels. Our study highlights the coordinated control of glioma cell proliferation and metabolism by ROS through (i) ATM-YAP1-driven apoptotic pathway and (ii) JNK-regulated metabolic adaptation. The elucidation of these newfound connections and the roles played by ROS to simultaneously shift metabolic program and induce apoptosis could provide insights toward the development of new anti-glioma strategies. PMID:24810048

Dixit, D; Ghildiyal, R; Anto, N P; Sen, E

2014-01-01

82

The Omega-3 Polyunsaturated Fatty Acid DHA Induces Simultaneous Apoptosis and Autophagy via Mitochondrial ROS-Mediated Akt-mTOR Signaling in Prostate Cancer Cells Expressing Mutant p53  

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Docosahexaenoic acid (DHA) induces autophagy-associated apoptotic cell death in wild-type p53 cancer cells via regulation of p53. The present study investigated the effects of DHA on PC3 and DU145 prostate cancer cell lines harboring mutant p53. Results show that, in addition to apoptosis, DHA increased the expression levels of lipidated form LC3B and potently stimulated the autophagic flux, suggesting that DHA induces both autophagy and apoptosis in cancer cells expressing mutant p53. DHA led to the generation of mitochondrial reactive oxygen species (ROS), as shown by the mitochondrial ROS-specific probe mitoSOX. Similarly, pretreatment with the antioxidant N-acetyl-cysteine (NAC) markedly inhibited both the autophagy and the apoptosis triggered by DHA, indicating that mitochondrial ROS mediate the cytotoxicity of DHA in mutant p53 cells. Further, DHA reduced the levels of phospho-Akt and phospho-mTOR in a concentration-dependent manner, while NAC almost completely blocked that effect. Collectively, these findings present a novel mechanism of ROS-regulated apoptosis and autophagy that involves Akt-mTOR signaling in prostate cancer cells with mutant p53 exposed to DHA. PMID:23841076

Shin, Soyeon; Jeong, Soyeon; Kim, Nayeong; Song, Kyoung-Sub; Heo, Jun-Young; Park, Ji-Hoon; Seo, Kang-Sik; Han, Jeongsu; Park, Jong-Il; Kweon, Gi-Ryang; Park, Seung-Kiel; Wu, Tong; Hwang, Byung-Doo; Lim, Kyu

2013-01-01

83

Cigarette smoke extract-induced BEAS-2B cell apoptosis and anti-oxidative Nrf-2 up-regulation are mediated by ROS-stimulated p38 activation.  

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Cigarette smoke contains reactive oxygen (ROS) that can cause oxidative stress. It increases the number of apoptotic and necrotic lung cells and further induces the development of chronic airway disease. In this study, we investigated the effects of cigarette smoke extract (CSE) on apoptosis in human bronchial epithelial cells (BEAS-2B). CSE exposure induced ROS generation and p38 mitogen-activated protein kinase (MAPK) activation that are associated with the activation of apoptosis-regulating signal kinase 1 (ASK-1). N-acetylcysteine (a general antioxidant) attenuated the CSE-induced ASK-1 and p38 MAPK activation and cell apoptosis, suggesting a triggering role of ROS in ASK-1/p38 MAPK activation during apoptotic progression. In contrast, the inhibition and knockdown of p38 attenuated the expression of anti-oxidant master NF-E2-related factor 2 (Nrf-2) and CSE-induced apoptosis, suggesting that p38 MAPK modulates Nrf-2 expression and presumably prevents cell apoptosis. Taken together, the data presented in this manuscript demonstrate that the ROS-dependent ASK-1/p38 signaling cascade regulates CSE-induced BEAS-2B cell apoptosis. In addition, anti-oxidative Nrf-2 is also up-regulated by the ROS/p38 signaling cascade in this progression. PMID:25134437

Lin, Xi-Xi; Yang, Xin-Fu; Jiang, Jun-Xia; Zhang, Shui-Juan; Guan, Yan; Liu, Ya-Nan; Sun, Yan-Hong; Xie, Qiang-Min

2014-12-01

84

Caspase-1/ASC Inflammasome-Mediated Activation of IL-1?–ROS–NF-?B Pathway for Control of Trypanosoma cruzi Replication and Survival Is Dispensable in NLRP3?/? Macrophages  

Science.gov (United States)

In this study, we have utilized wild-type (WT), ASC?/?, and NLRP3?/? macrophages and inhibition approaches to investigate the mechanisms of inflammasome activation and their role in Trypanosoma cruzi infection. We also probed human macrophages and analyzed published microarray datasets from human fibroblasts, and endothelial and smooth muscle cells for T. cruzi-induced changes in the expression genes included in the RT Profiler Human Inflammasome arrays. T. cruzi infection elicited a subdued and delayed activation of inflammasome-related gene expression and IL-1? production in m?s in comparison to LPS-treated controls. When WT and ASC?/? macrophages were treated with inhibitors of caspase-1, IL-1?, or NADPH oxidase, we found that IL-1? production by caspase-1/ASC inflammasome required reactive oxygen species (ROS) as a secondary signal. Moreover, IL-1? regulated NF-?B signaling of inflammatory cytokine gene expression and, subsequently, intracellular parasite replication in macrophages. NLRP3?/? macrophages, despite an inability to elicit IL-1? activation and inflammatory cytokine gene expression, exhibited a 4-fold decline in intracellular parasites in comparison to that noted in matched WT controls. NLRP3?/? macrophages were not refractory to T. cruzi, and instead exhibited a very high basal level of ROS (>100-fold higher than WT controls) that was maintained after infection in an IL-1?-independent manner and contributed to efficient parasite killing. We conclude that caspase-1/ASC inflammasomes play a significant role in the activation of IL-1?/ROS and NF-?B signaling of cytokine gene expression for T. cruzi control in human and mouse macrophages. However, NLRP3-mediated IL-1?/NF?B activation is dispensable and compensated for by ROS-mediated control of T. cruzi replication and survival in macrophages. PMID:25372293

Dey, Nilay; Sinha, Mala; Gupta, Shivali; Gonzalez, Mariela Natacha; Fang, Rong; Endsley, Janice J.; Luxon, Bruce A.; Garg, Nisha Jain

2014-01-01

85

Arsenic and chromium in drinking water promote tumorigenesis in a mouse colitis-associated colorectal cancer model and the potential mechanism is ROS-mediated Wnt/?-catenin signaling pathway  

International Nuclear Information System (INIS)

Exposure to carcinogenic metals, such as trivalent arsenic [As(III)] and hexavalent chromium [Cr(VI)], through drinking water is a major global public health problem and is associated with various cancers. However, the mechanism of their carcinogenicity remains unclear. In this study, we used azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse colitis-associated colorectal cancer model to investigate their tumorigenesis. Our results demonstrate that exposure to As(III) or Cr(VI), alone or in combination, together with AOM/DSS pretreatment has a promotion effect, increasing the colorectal tumor incidence, multiplicity, size, and grade, as well as cell inflammatory response. Two-dimensional differential gel electrophoresis coupled with mass spectrometry revealed that As(III) or Cr(VI) treatment alone significantly changed the density of proteins. The expression of ?-catenin and phospho-GSK was increased by treatment of carcinogenic metals alone. Concomitantly, the expression of NADPH oxidase1 (NOX1) and the level of 8-OHdG were also increased by treatment of carcinogenic metals alone. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, were decreased. Similarly, in an in vitro system, exposure of CRL-1807 to carcinogenic metals increased reactive oxygen species (ROS) generation, the expression of ?-catenin, phospho-GSK, and NOX1. Inhibition of ROS generation by addition of SOD or catalase inhibited ?-catenin expression and activity. Our study provides a new animal model to study the carcinogenicity of As(III) and Cr(VI) and suggests that As(III) and Cr(VI) promote colorectal cancer tumorigenesis, at least partly, through ROS-mediated Wnt/?-catenin signaling pathway. -- Highlights: ? Carcinogenic metals in drinking water promote colorectal tumor formation in vivo. ? Carcinogenic metals induce ?-catenin activation in vivo and in vitro. ? ROS generation induced by carcinogenic metals mediated ?-catenin activation.

86

Arsenic and chromium in drinking water promote tumorigenesis in a mouse colitis-associated colorectal cancer model and the potential mechanism is ROS-mediated Wnt/?-catenin signaling pathway  

Energy Technology Data Exchange (ETDEWEB)

Exposure to carcinogenic metals, such as trivalent arsenic [As(III)] and hexavalent chromium [Cr(VI)], through drinking water is a major global public health problem and is associated with various cancers. However, the mechanism of their carcinogenicity remains unclear. In this study, we used azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse colitis-associated colorectal cancer model to investigate their tumorigenesis. Our results demonstrate that exposure to As(III) or Cr(VI), alone or in combination, together with AOM/DSS pretreatment has a promotion effect, increasing the colorectal tumor incidence, multiplicity, size, and grade, as well as cell inflammatory response. Two-dimensional differential gel electrophoresis coupled with mass spectrometry revealed that As(III) or Cr(VI) treatment alone significantly changed the density of proteins. The expression of ?-catenin and phospho-GSK was increased by treatment of carcinogenic metals alone. Concomitantly, the expression of NADPH oxidase1 (NOX1) and the level of 8-OHdG were also increased by treatment of carcinogenic metals alone. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, were decreased. Similarly, in an in vitro system, exposure of CRL-1807 to carcinogenic metals increased reactive oxygen species (ROS) generation, the expression of ?-catenin, phospho-GSK, and NOX1. Inhibition of ROS generation by addition of SOD or catalase inhibited ?-catenin expression and activity. Our study provides a new animal model to study the carcinogenicity of As(III) and Cr(VI) and suggests that As(III) and Cr(VI) promote colorectal cancer tumorigenesis, at least partly, through ROS-mediated Wnt/?-catenin signaling pathway. -- Highlights: ? Carcinogenic metals in drinking water promote colorectal tumor formation in vivo. ? Carcinogenic metals induce ?-catenin activation in vivo and in vitro. ? ROS generation induced by carcinogenic metals mediated ?-catenin activation.

Wang, Xin; Mandal, Ardhendu K. [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Saito, Hiroshi [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States); Pulliam, Joseph F.; Lee, Eun Y. [Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY 40536 (United States); Ke, Zun-Ji; Lu, Jian; Ding, Songze [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Li, Li [Department of Family Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Shelton, Brent J.; Tucker, Thomas [Markey Cancer Control Program, University of Kentucky, Lexington, KY 40504 (United States); Evers, B. Mark [Department of Surgery and Physiology, Lucille P. Markey Cancer Center, University of Kentucky, Lexington, KY 40536 (United States); Zhang, Zhuo [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@uky.edu [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States)

2012-07-01

87

Low fucose containing bacterial polysaccharide facilitate mitochondria-dependent ROS-induced apoptosis of human lung epithelial carcinoma via controlled regulation of MAPKs-mediated Nrf2/Keap1 homeostasis signaling.  

Science.gov (United States)

Reactive oxygen species (ROS), the key mediators of cellular oxidative stress and redox dysregulation involved in cancer initiation and progression, have recently emerged as promising targets for anticancer drug discovery. Continuous free radical assault upsets homeostasis in cellular redox system and regulates the associated signaling pathways to mediate stress-induced cell death. This study investigates the dose-specific pro-oxidative behavior of a bacterial fucose polysaccharide, which attenuated proliferation of different cancer cells. In the fermentation process, Bacillus megaterium RB-05 [GenBank Accession Number HM371417] was found to biosynthesize a polysaccharide with low-fucose content (4.9%), which conferred the maximum anti-proliferative activity (750?µg/mL) against human lung cancer epithelial cells (A549) during preliminary screening. Structural elucidation and morphological characterization of the duly purified polysaccharide was done using HPLC, GC-MS, (1) H/(13) C NMR, and microscopy. The polysaccharide exhibited concentration- and time-dependent anti-proliferative effects against A549 cells by inducing intracellular ROS level and regulating the mitochondrial membrane-permeability following the apoptotic pathway. This process encompasses activation of caspase-8/9/3/7, increase in the ratio of Bax/Bcl2 ratio, translocation of Bcl2-associated X protein (Bax) and cytochrome c, decrease in expression of anti-apoptotic members of Bcl2 family, and phosphorylation of mitogen activated protein kinases (MAPKs). Apoptosis was attenuated upon pretreatment with specific caspase-inhibitors. Simultaneously, during apoptosis, the ROS-mediated stress as well as activated MAPKs triggered nuclear translocation of transcription factors like nuclear factor (erythroid-derived)-like 2 (Nrf2) and promoted further transcription of downstream cytoprotective genes, which somehow perturbed the chemotherapeutic efficacy of the polysaccharide, although using CuPP, a chemical inhibitor of HO-1, apoptosis increased significantly (P?

Chowdhury, Sougata Roy; Sengupta, Suman; Biswas, Subir; Sen, Ramkrishna; Sinha, Tridib Kumar; Basak, Ratan Kumar; Adhikari, Basudam; Bhattacharyya, Arindam

2014-10-30

88

Snake venom toxin from vipera lebetina turanica induces apoptosis of colon cancer cells via upregulation of ROS- and JNK-mediated death receptor expression  

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Abstract Background Abundant research suggested that the cancer cells avoid destruction by the immune system through down-regulation or mutation of death receptors. Therefore, it is very important that finding the agents that increase the death receptors of cancer cells. In this study, we demonstrated that the snake venom toxin from Vipera lebetina turanica induce the apoptosis of colon cancer cells through reactive oxygen species (ROS) and c-Jun N-terminal kinases (...

Park Mi; Jo MiRan; Won Dohee; Song Ho; Han Sang; Song Min; Hong Jin

2012-01-01

89

Nitric oxide signals ROS scavenger-mediated enhancement of PAL activity in nitrogen-deficient Matricaria chamomilla roots: side effects of scavengers.  

Science.gov (United States)

Owing to the abundance of phenolic metabolites in plant tissue, their accumulation represents an important tool for stress protection. However, the regulation of phenolic metabolism is still poorly known. The regulatory role of reactive oxygen species (ROS) in the activity of phenylalanine ammonia-lyase (PAL) in nitrogen (N)-deficient chamomile roots treated for 24 h was studied using three ROS scavengers [dithiothreitol (DTT), salicylhydroxamic acid, and sodium benzoate]. Scavengers decreased the level of hydrogen peroxide and/or superoxide (and up-regulated ascorbate/guaiacol peroxidase and glutathione reductase), but, surprisingly, stimulated PAL activity. This up-regulation was correlated with increases in nitric oxide (NO) content, total soluble phenols, selected phenolic acids, and, partially, lignin (being expressed the most in DTT-exposed roots). We therefore tested the hypothesis that NO may be involved in these changes. Application of 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) decreased PAL activity and the accumulation of soluble phenols in all treatments. Exogenous H(2)O(2) and NO also stimulated PAL activity and the accumulation of phenols. We conclude that NO, in addition to hydrogen peroxide, may regulate PAL activity during N deficiency. The anomalous effect of PTIO on NO content and possible mechanism of ROS scavenger-evoked NO increases in light of the current knowledge are also discussed. PMID:19345259

Kovácik, Jozef; Klejdus, Borivoj; Backor, Martin

2009-06-15

90

cFos Mediates cAMP-Dependent Generation of ROS and Rescue of Maturation Program in Retinoid-Resistant Acute Promyelocytic Leukemia Cell Line NB4-LR1  

Science.gov (United States)

A determining role has been assigned to cAMP in the signaling pathways that relieve resistance to anti-leukemia differentiation therapy. However, the underlying mechanisms have not been elucidated yet. Here, we identify cFos as a critical cAMP effector, able to regulate the re-expression and splicing of epigenetically silenced genes associated with maturation (CD44) in retinoid-resistant NB4-LR1 leukemia cells. Furthermore, using RNA interference approach, we show that cFos mediates cAMP-induced ROS generation, a critical mediator of neutrophil maturation, and in fine differentiation. This study highlights some of the mechanisms by which cAMP acts to overcome resistance, and reveals a new alternative cFos-dependent pathway which, though nonexistent in retinoid-sensitive NB4 cells, is essential to rescue the maturation program of resistant cells. PMID:23209736

Carrier, Jean-Luc; Javadi, Pasha; Bourrier, Emilie; Camus, Céline; Ségal-Bendirdjian, Evelyne; Karniguian, Aïda

2012-01-01

91

MAP17 and the double-edged sword of ROS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reactive oxygen species, ROS, are beneficially involved in many signaling pathways that control development and maintain cellular homeostasis. In physiological conditions, a tightly regulated redox balance protects cells from injurious ROS activity, but if the balance is altered, it promotes various pathological conditions including cancer. Understanding the duality of ROS as cytotoxic molecules and key mediators in signaling cascades may provide novel opportunities for improved cancer therap...

Carnero, Amancio

2012-01-01

92

Assessment of in-utero venlafaxine induced, ROS-mediated, apoptotic neurodegeneration in fetal neocortex and neurobehavioral sequelae in rat offspring.  

Science.gov (United States)

Venlafaxine (VEN), a serotonin and noradrenaline reuptake inhibitor is being used as a drug of choice for treating clinical depression even during pregnancy. It is an important therapeutic option in the treatment of perinatal depression, but the effects of VEN on fetus and the newborn are uncertain. Therefore, present study was undertaken to investigate the safety of in-utero exposure to VEN in terms of developmental neurotoxicity and neurodegenerative potential by using prenatal rat model. The selected doses of VEN (25, 40 and 50mg/kg) were administered to pregnant rats from GD 5 to 19 through oral gavage. The fetal brains were dissected and processed for histopathological measurements of neocortical thickness that showed significant reduction. Considering vulnerability of immature brain to free radical injury, VEN exposed neocortices were tested for reactive oxygen species (ROS) levels which were significantly increased. As ROS play important role in the initiation of apoptotic mechanisms, we explored for in situ detection of apoptosis by confocal microscopy that showed enhanced apoptosis including chromatin condensation which was further reconfirmed by electron microscopy. Substantially increased levels of pro-apoptotic protein Bax and decreased levels of anti-apoptotic protein Bcl2 as shown by western blotting also supported the increased neuro-apoptotic degeneration. For further correlation of these findings, prenatally VEN exposed young-adult rat offspring were assessed for open field exploratory behavior that showed increased anxiety-like and stereotypic responses indicating disturbed neurobehavioral pattern. The study concludes that prenatal VEN exposure may primarily enhance ROS generation that plays a key role in regulating release of proapoptotic factors from mitochondria and thereby enhancing apoptotic neurodegeneration that affect proliferation, migration and differentiation of cells, resulting in neuronal deficits manifested as long term neurobehavioral impairments. PMID:25450524

Singh, Manish; Singh, K P; Shukla, Shubha; Dikshit, Madhu

2015-02-01

93

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Yukiko K. Nakamura

2010-07-01

94

Selenium-platinum coordination compounds as novel anticancer drugs: selectively killing cancer cells via a reactive oxygen species (ROS)-mediated apoptosis route.  

Science.gov (United States)

We report the preparation of selenium-containing platinum-based anticancer drug EG-Se/Pt. EG-Se/Pt was obtained from the coordination of selenium-containing molecules (EG-Se) with cisplatin (CDDP). The structure of EG-Se/Pt was characterized by (1) H and (77) Se?NMR spectroscopy, XPS, ESI-MS, and MALDI-TOF. In aqueous solution, EG-Se/Pt self-assembles to form spherical aggregates. EG-Se/Pt shows enhanced stability against dilution and high salt concentration compared with EG-Se. EG-Se/Pt induces cell apoptosis via reactive oxygen species (ROS), which leads to high selectivity between cancer cells and normal cells in cytotoxicity assays. More importantly, EG-Se/Pt effectively inhibits tumor growth in vivo in tumor-bearing mice. It is anticipated that tuning the ROS level through the assembly of selenium-containing molecules can be a general method to realize anticancer selectivity. PMID:24844800

Zeng, Lingwu; Li, Yang; Li, Tianyu; Cao, Wei; Yi, Yu; Geng, Weijia; Sun, Zhiwei; Xu, Huaping

2014-08-01

95

Strategy to enhance the anticancer efficacy of X-ray radiotherapy in melanoma cells by platinum complexes, the role of ROS-mediated signaling pathways.  

Science.gov (United States)

Radiotherapy plays an important role in treatment of cancers with low toxicity to the surrounding normal tissues. However, it still fails to eradicate hypoxic tumors due to the occurrence of radioresistance. Therefore, the search for new radiation sensitizers is of great significance. Platinum (Pt) complexes have been identified as potential radiation sensitizers to increase the sensitivity of cancer cells to radiotherapy. In the present study, we have synthesized four Pt complexes containing (2 - benzimidazole [4, 5-f] - [1, 10] phenanthroline) ligand and found that they could effectively enhance the X-ray-induced growth inhibition against A375 human melanoma cells through induction of G2/M cell cycle arrest. In contrast, they showed much lower cytotoxicity toward human normal cells. The complexes also dramatically inhibited the TrxR activity and caused intracellular ROS overproduction, due to the Auger electron effect of heavy metal element under X-ray radiation. Excessive ROS triggered DNA damage and activated downstream signaling pathways, including the phosphorylation of p53 and p38MAPK, and down-regulation of phosphorylated AKT and ERK, finally resulted in increase of radiosensitivity and inhibition of tumor reproduction. Taken together, our results suggest that the synthetic Pt complexes could be further developed as sensitizers of X-ray radiotherapy. PMID:25135223

Xie, Qiang; Lan, Guoqiang; Zhou, Yangliang; Huang, Jiamin; Liang, Yuanwei; Zheng, Wenjie; Fu, Xiaoyan; Fan, Cundong; Chen, Tianfeng

2014-11-01

96

1 alpha,25(OH)2 vitamin D3-mediated stimulation of outward anionic currents in osteoblast-like ROS 17/2.8 cells.  

Science.gov (United States)

1 alpha,25-dihydroxyvitamin-D3 [1 alpha,25(OH)2D3] is known to potentiate in osteoblast-like rat osteosarcoma cells (ROS 17/2.8) the influx of Ca2+ through voltage-activated L-type Ca2+ channels. In the present study, by means of the whole-cell patch-clamp technique, we found that physiological concentrations of 1 alpha,25(OH)2D3 (5-5000 x 10(-11) M) also stimulate, in a dose-dependent manner, outwardly rectifying anionic currents over the course of 1-5 minutes. These currents, recorded in the presence of 130 mM glutamate or approximately 140 mM C1- in the external solution, were blocked by 200 microM DIDS, a stilbene derivative selective for C1- channels. We conclude that, in addition to the already known effects of 1 alpha,25(OH)2D3 on Ca2+ channels, the hormone also enhances in ROS 17/2.8 cells an outward anion conductance. This is the first report concerning activation of anion channels by 1 alpha,25(OH)2D3. PMID:8753799

Zanello, L P; Norman, A W

1996-08-14

97

Radiation-induced apoptosis of neural precursors cell cultures: early modulation of the response mediated by reactive oxygen and nitrogen species (ROS/RNS)  

International Nuclear Information System (INIS)

Apoptosis, the typical mode of radiation-induced cell death in developing Central Nervous System (CNS), is closely related with the oxidative status. Enhanced radiation-induced generation of ROS/RNS has been observed after exposures to low radiation doses leading to cellular amplification of signal transduction and further molecular and cellular radiation-responses. Moreover Nitric oxide (NO) and hydroxyl radical are implicated in dopaminergic neurotoxicity in different parading. This study is an attempt to address the participation of radiation-induced free radicals production, the contribution of endogenous NO generation, and the excitonic pathway, in the radiation-induced apoptosis of neural cortical precursors. Cortical cells obtained from at 17 gestational day (gd) were irradiated with doses from 0,2 Gy to 2 Gy at a dose-rate of 0.3 Gy/m. A significant decrease of Luminol-dependent Chemiluminescence was evident 30 m after irradiation reaching basal levels at 120 m follow for a tendency to increasing values Incubations with Superoxide Dismatuse (SOD) decreased significantly the chemiluminescence in irradiated samples NO content estimated by measuring the stable products NO2 and NO3 released to the culture medium in the same period, has shown a time-dependent accumulation from 1 h post-irradiation. the apoptosis, determined 24 h post-irradiation by flow cytometry, morphology and DNA fragmentation revealed a dose-effect relationship with signifled a dose-effect relationship with significant differences from 0.4 Gy. The samples pre-treated with 10 mM of N-acetyl cysteine (NAC) a precursor of intracellular GSH synthesis, shown a significant decrease of the apoptosis. Apoptosis was significantly increased in irradiated cells after inhibition of nitric oxide synthase (NOS) byL-NAME. We conclude that ROS/RNS play a pivotal role in the early signaling pathways leading to a radiation-induced cell death. (Author) 40 refs

98

Ischemia/reperfusion-induced upregulation of TIGAR in brain is mediated by SP1 and modulated by ROS and hormones involved in glucose metabolism.  

Science.gov (United States)

We previously found that TIGAR (TP53-induced glycolysis and apoptosis regulator) was upregulated in response to ischemia/reperfusion insult in a TP53-independent manner. The present study sought to investigate the regulatory mechanisms of TIGAR upregulation in animal and cellular models of stroke. The animal and cellular models of ischemia/reperfusion were produced by transient middle cerebral artery occlusion and reperfusion (tMCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R), respectively. The expression of TIGAR protein in cortical tissues and hippocampal neuronal cell line HT22 cells or primary neurons was determined. Glucose, hormones and hydrogen peroxide (H2O2) were administered to mice via injection into the tail vein or lateral ventricle or directly added into cell culture medium. In mice subjected to tMCAO/R, the blood glucose level rapidly increased, peaking at 0.5?h and then declined. TIGAR protein was also significantly increased and then declined with a delayed time-course. The increase in TIGAR protein was blunted when blood glucose levels were controlled with insulin. However, administering glucose solution to mice or adding glucose to cell culture medium had no effect on TIGAR protein levels. In contrast adrenaline, hydrocortisone, glucagon and H2O2 significantly increased TIGAR protein expression, whereas insulin inhibited TIGAR expression. The transcription factor SP1 was induced by ischemia/reperfusion ahead of TIGAR upregulation. Inhibiting SP1 with mithramycin A or silencing SP1 with siRNA blocked the ischemia-induced TIGAR upregulation. These results suggest that ROS and hormones regulating blood glucose metabolism play a role in ischemia/reperfusion-induced TIGAR upregulation. PMID:25445985

Sun, Meiling; Li, Mei; Huang, Qiao; Han, Feng; Gu, Jin-Hua; Xie, Jiaming; Han, Rong; Qin, Zheng-Hong; Zhou, Zhipeng

2015-01-01

99

Cu(II) inhibits hIAPP fibrillation and promotes hIAPP-induced beta cell apoptosis through induction of ROS-mediated mitochondrial dysfunction.  

Science.gov (United States)

Human islet amyloid polypeptide (hIAPP), the major component of the amyloid deposits found in the pancreatic islets of patients with type 2 diabetes mellitus (T2DM), plays a central role in the loss of insulin-secreting pancreatic beta cells. Misfolded hIAPP fibrillating in islet beta cells may be one of the causations for T2DM. Studies have showed that fibrosis of hIAPP was inhibited by copper compounds while hIAPP-induced cytotoxicity was greatly stimulated. In this study, the suppression effects of three different forms of copper compounds CuCl2, CuSO4 and Cu(Gly)2 on amyloid fibril formation were examined in vitro. The results demonstrated that Cu(II) could interact with hIAPP to suppress the fibrosis without involvement of the anions. The fibrosis of hIAPP was inhibited by CuCl2, CuSO4 and Cu(Gly)2 with a similar degree. The particle size of hIAPP aggregates was decreased, which was further confirmed in atomic force microscopy (AFM) and transmission electron microscopy (TEM) images. Moreover, approximative cytotoxicity-enhancing levels between CuCl2, CuSO4 and Cu(Gly)2 on hIAPP were also observed in INS-1 cells. Studies on the action mechanisms displayed that copper compounds increased hIAPP-induced cytotoxicity by facilitating apoptosis-promoting effect of hIAPP, which was dominated mainly by cation. Furthermore, Cu(II)-promoted ROS overproduction and mitochondrial disruption might be the main reason for the enhanced apoptosis. Taken together, our studies demonstrate clear interaction mechanisms of Cu(II) and hIAPP in pancreatic beta cells, and provide useful information for our understanding and treatment of T2DM. PMID:25108186

Ma, Lijuan; Li, Xiaoling; Wang, Yi; Zheng, Wenjie; Chen, Tianfeng

2014-11-01

100

Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways.  

Science.gov (United States)

Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 ?M significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. PMID:25018059

Chang, Chun-Yu; Shen, Chao-Yu; Kang, Chao-Kai; Sher, Yuh-Pyng; Sheu, Wayne H-H; Chang, Chia-Che; Lee, Tsung-Han

2014-09-15

 
 
 
 
101

Granzyme B-induced mitochondrial ROS are required for apoptosis.  

Science.gov (United States)

Caspases and the cytotoxic lymphocyte protease granzyme B (GB) induce reactive oxygen species (ROS) formation, loss of transmembrane potential and mitochondrial outer membrane permeabilization (MOMP). Whether ROS are required for GB-mediated apoptosis and how GB induces ROS is unclear. Here, we found that GB induces cell death in an ROS-dependent manner, independently of caspases and MOMP. GB triggers ROS increase in target cell by directly attacking the mitochondria to cleave NDUFV1, NDUFS1 and NDUFS2 subunits of the NADH: ubiquinone oxidoreductase complex I inside mitochondria. This leads to mitocentric ROS production, loss of complex I and III activity, disorganization of the respiratory chain, impaired mitochondrial respiration and loss of the mitochondrial cristae junctions. Furthermore, we have also found that GB-induced mitocentric ROS are necessary for optimal apoptogenic factor release, rapid DNA fragmentation and lysosomal rupture. Interestingly, scavenging the ROS delays and reduces many of the features of GB-induced death. Consequently, GB-induced ROS significantly promote apoptosis.Cell Death and Differentiation advance online publication, 31 October 2014; doi:10.1038/cdd.2014.180. PMID:25361078

Jacquemin, G; Margiotta, D; Kasahara, A; Bassoy, E Y; Walch, M; Thiery, J; Lieberman, J; Martinvalet, D

2014-10-31

102

Intracellular ROS Scavenging Activity and Downregulation of Inflammatory Mediators in RAW264.7 Macrophage by Fresh Leaf Extracts of Pseuderanthemum palatiferum  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Beneficial antioxidant phytochemicals are found in many medicinal plants. Pseuderanthemum palatiferum (PP), a well-known Vietnamese traditional medicinal plant in Thailand, has long been used in folk medicine for curing inflammatory diseases, often with limited support of scientific research. Therefore, this study aimed to determine antioxidant and modulation of inflammatory mediators of ethanol and water extracts of PP (EEP and WEP, resp.). WEP had significantly higher phenolic and flavonoid...

Patcharawan Sittisart; Benjamart Chitsomboon

2014-01-01

103

The ROS Workshop  

CERN Document Server

The first week of February saw the taking place of the ReadOut Subsystem (ROS) workshop. The ROS is the subsystem of the Trigger, DAQ & DCS project which receives and buffers data from the detector ReadOut Drivers (RODs). On request it then provides a subset of this buffered data, the so-called Regions of Interest (RoI), to the Level 2 trigger. Using the subsequent Level 2 trigger decision, the ROS either removes the buffered event data from its buffers or sends the full event data to the Event Filter for further processing. The workshop took place over a four-day period at a location in the Jura. The average daily attendance was twenty people, which mainly represented the five main ATLAS institutes currently engaged in this Trigger, DAQ & DCS activity. The aim of the workshop was to bring to an end the current prototyping activities in this area and launch the next, final, phase of prototyping. This new phase of prototyping will build on the successful activities of the previous phase and will focus...

Francis, D.

104

Damage of lipopolysaccharides in outer cell membrane and production of ROS-mediated stress within bacteria makes nano zinc oxide a bactericidal agent  

Science.gov (United States)

Zinc oxide nanoparticle (ZNP) has been synthesized by microwave-assisted technique with the aid of a buffer solution. ZNP inhibited the growth of bacterial system Escherichia coli, even its multidrug-resistant counterpart as well. Systematic evaluation reveals that bioavailable crystalline ZNP damages the lipopolysaccharide layer from outer membrane (OM) of E. coli, subsequently damages the OM followed by inner membrane, enters within the cell and generates extensive reactive oxygen species-mediated damage. A series of biochemical, biophysical and molecular techniques have been used to reach the conclusion. We believe this work is expected to enlighten the detailed mode of action study in bacterial system.

Patra, Prasun; Roy, Shuvrodeb; Sarkar, Sampad; Mitra, Shouvik; Pradhan, Saheli; Debnath, Nitai; Goswami, Arunava

2014-12-01

105

Effect of 15-lipoxygenase metabolites, 15-(S)-HPETE and 15-(S)-HETE on chronic myelogenous leukemia cell line K-562: reactive oxygen species (ROS) mediate caspase-dependent apoptosis.  

Science.gov (United States)

Growth inhibitory effects of 15-lipoxygenase-1 [13-(S)-HPODE and 13-(S)-HODE] and 15-lipoxygenase-2 [15-(S)-HPETE and 15-(S)-HETE] (15-LOX-1 and LOX-2) metabolites and the underlying mechanisms were studied on chronic myeloid leukemia cell line (K-562). The hydroperoxy metabolites, 15-(S)-HPETE and 13-(S)-HPODE rapidly inhibited the growth of K-562 cells by 3h with IC(50) values, 10 and 15microM, respectively. In contrast, the hydroxy metabolite of 15-LOX-2, 15-(S)-HETE, showed 50% inhibition only at 40microM by 6h and 13-(S)-HODE, hydroxy metabolite of 15-LOX-1, showed no significant effect up to 160microM. The cells exposed to 10microM of 15-(S)-HPETE and 40microM of 15-(S)-HETE showed typical apoptotic features like release of cytochrome c, caspase-3 activation and PARP-1 (poly(ADP) ribose polymerase-1) cleavage. A flow cytometry based DCFH-DA analysis and inhibitory studies with DPI, a pharmacological inhibitor of NADPH oxidase, NAC (N-acetyl cysteine) and GSH revealed that NADPH oxidase-mediated generation of ROS is responsible for caspase-3 activation and subsequent induction of apoptosis in the K-562 cell line. PMID:17517376

Mahipal, Suraneni V K; Subhashini, Jagu; Reddy, Madhava C; Reddy, Metukuri M; Anilkumar, Kotha; Roy, Karnati R; Reddy, Gorla V; Reddanna, Pallu

2007-07-15

106

Effects of temperature on complexes I and II mediated respiration, ROS generation and oxidative stress status in isolated gill mitochondria of the mud crab Scylla serrata.  

Science.gov (United States)

Effects of fluctuations in habitat temperature (18-30°) on mitochondrial respiratory behavior and oxidative metabolic responses in the euryhaline ectotherm Scylla serrata are not fully understood. In the present study, effects of different temperatures ranging from 12 to 40°C on glutamate and succinate mediated mitochondrial respiration, respiratory control ratio (RCR), ATP generation rate, ratio for the utilization of phosphate molecules per atomic oxygen consumption (P/O), levels of lipid peroxidation and H2O2 in isolated gill mitochondria of S. serrata are reported. The pattern of variation in the studied parameters was similar for the two substrates at different temperatures. The values recorded for RCR (?3) and P/O ratio (1.4-2.7) at the temperature range of 15-25°C were within the normal range reported for other animals (3-10 for RCR and 1.5-3 for P/O). Values for P/O ratio, ATP generation rate and RCR were highest at 18°C when compared to the other assay temperatures. However, at low and high extreme temperatures, i.e. at 12 and 40°C, states III and IV respiration rates were not clearly distinguishable from each other indicating that mitochondria were completely uncoupled. Positive correlations were noticed between temperature and the levels of both lipid peroxidation and H2O2. It is inferred that fluctuations on either side of ambient habitat temperature may adversely influence mitochondrial respiration and oxidative metabolism in S. serrata. The results provide baseline data to understand the impacts of acute changes in temperature on ectotherms inhabiting estuarine or marine environments. PMID:24679979

Paital, Biswaranjan; Chainy, G B N

2014-04-01

107

Sending ROS on a Bullet Train  

Science.gov (United States)

Plants have to contend with biotic stress, such as disease, mechanical wounding, and herbivory, as well as abiotic stress, such as heat, cold, and salinity. An early warning system for these threats would prevent or reduce the damage suffered by plants. Such a warning system should allow the signal to be rapidly generated and sent over long distances. The study of systemic signaling in plants has been a major scientific challenge. Reactive oxygen species (ROS) are among the systemic signals that have been proposed. Now, the exciting discovery that systemic ROS signaling is mediated by an NADPH (nicotinamide adenine dinucleotide phosphate, reduced form) oxidase opens the door to understanding the molecular mechanisms that initiate and propagate a rapid systemic signal.

Hann Ling Wong (Japan;Nara Institute of Science and Technology REV); Ko Shimamoto (Japan;Nara Institute of Science and Technology REV)

2009-09-29

108

Gravitropic response induced by coumarin: evidences of ROS distribution involvement.  

Science.gov (United States)

Coumarin effects on gravitropic responses of Arabidopsis thaliana roots were here evaluated. Coumarin alone did not cause any alteration on gravitropic response showing a behavior similar to control plants. In contrast, TIBA and NPA, two auxin transport inhibitors, strongly modified root gravitropic responses. The addition of coumarin to the medium together with TIBA or NPA partially restored the effect of both inhibitors. Simultaneously, a semi-quantitative evaluation of ROS distribution was performed on root tips. TIBA and NPA caused a wide distribution of O 2(-), ROS oxidant species, around the root tip which disappeared with coumarin addition to both treatments, restoring ROS localized distribution. These results indicated a strong correlation between ROS distribution and coumarin-mediated recovery of root gravitropism. PMID:23299434

Lupini, Antonio; Araniti, Fabrizio; Sunseri, Francesco; Abenavoli, Maria Rosa

2013-02-01

109

Regulating the regulator of ROS production.  

Science.gov (United States)

Balancing inflammatory reactive oxygen species (ROS) production is essential for safely eliminating pathogenic microbes. The newly described protein Negative Regulator of ROS (NRROS) dampens ROS production by restricting NOX2 availability, and thus "cools-off" inflammation. PMID:24839902

Bonini, Marcelo G; Malik, Asrar B

2014-08-01

110

Effect of electroacupuncture to prevent selenite-induced cataract in Wistar rats / Efeito da eletro-acupuntura na prevenção da catarata induzida por selenito de sódio em ratos Wistar  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese OBJETIVO: Avaliar o efeito da eletro-acupuntura na prevenção da catarata induzida por selenito de sódio em modelo experimental. MÉTODO: Cinqüenta filhotes de ratos Wistar foram randomizados em 5 grupos: no Grupo 1 (Controle, n=10) nenhum procedimento foi realizado. Grupo 2 (Selenito, n=10), selenito [...] de sódio (30 µmoles/kg) foi injetado por via subcutânea no décimo dia de vida. No Grupo 3 (Anestesia, n=10), filhotes receberam a mesma dose de selenito e sofreram anestesia inalatória com éter etílico durante 10 minutos diariamente por 1 semana. Grupo 4 (eletro-acupuntura, n=10), os animais sofreram os mesmos procedimentos do Grupo 3, porém também receberam eletro-acupuntura (2 Hz, 50 mA) aplicada nos pontos Neiguan (PC 6) e Guangming (GB37) durante o período de anestesia. Grupo 5 (Sham, n=10), os ratos foram submetidos aos mesmos procedimentos que o Grupo 4, porém as agulhas foram aplicadas em pontos falsos. O desenvolvimento da catarata foi avaliado após uma semana por lâmpada de fenda. RESULTADOS: Todos os animais controles (Grupo 1) não desenvolveram catarata. Todos os ratos dos grupos 2, 3 e 5 desenvolveram catarata grave. No Grupo 4 (eletro-acupuntura), 45% dos olhos não desenvolveram catarata e trinta por cento desenvolveram catarata menos grave que aos Grupos 2, 3 e 5. A diferença entre os grupos foi estatisticamente significante (p Abstract in english PURPOSE: To investigate whether electroacupuncture can prevent selenite-induced cataract in an experimental model. METHODS: Fifty Wistar rat pups were randomized into 5 groups of 10 animals: Group 1 (control), no procedure was performed; Group 2 (selenite), sodium selenite (30 micromoles/kg body wei [...] ght) was injected subcutaneously between postpartum days 10 to 12; Group 3 (anesthesia) received the same dose of selenite and underwent ether inhalation anesthesia during 10 minutes daily for one week; Group 4 (electroacupuncture) underwent the same procedure of Group 3, but also receiving electroacupuncture (2 Hz, 50 mA) applied to the Neiguan (PC6) and Guangming (GB37) acupoints during the anesthesia period; and Group 5 (Sham) underwent the same procedures of Group 4, but needles were applied to non-acupoints. The development of cataract was assessed one week later, and its density was graded by slit lamp biomicroscopy. RESULTS: All control rats lenses (Group 1) were clear. Groups 2, 3 and 5 rats developed more severe cataract or complete opacification. In Group 4 (electroacupuncture), 45% of eyes did not develop cataract while thirty per cent developed less severe cataract than Groups 2, 3 and 5. The between-group difference was statistically significant (p

Angelino Julio, Cariello; Fábio Henrique, Casanova; Acácio Alves de Souza, Lima Filho; Yara, Juliano; Angela, Tabosa.

2006-06-01

111

Menadione triggers cell death through ROS-dependent mechanisms involving PARP activation without requiring apoptosis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Low levels of reactive oxygen species (ROS) can function as redox-active signaling messengers, whereas high levels of ROS induce cellular damage. Menadione generates ROS through redox cycling, and high concentrations trigger cell death. Previous work suggests that menadione triggers cytochrome c release from mitochondria, while other studies implicate activation of the mitochondrial permeability transition poreas the mediator of cell death. We investigated menadione-induced cell death in gene...

Loor, Gabriel; Kondapalli, Jyothisri; Schriewer, Jacqueline M.; Chandel, Navdeep S.; Vanden Hoek, Terry L.; Schumacker, Paul T.

2010-01-01

112

ROS-induced ATF3 causes susceptibility to secondary infections during sepsis-associated immunosuppression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sepsis, sepsis-induced hyperinflammation and subsequent sepsis-associated immunosuppression (SAIS) are important causes of death. Here we show in humans that the loss of the major reactive oxygen species (ROS) scavenger, glutathione (GSH), during SAIS directly correlates with an increase in the expression of activating transcription factor 3 (ATF3). In endotoxin-stimulated monocytes, ROS stress strongly superinduced NF-E2–related factor 2 (NRF2)–dependent ATF3. In vivo, this ROS-mediated ...

Hoetzenecker, Wolfram; Echtenacher, Bernd; Guenova, Emmanuella; Hoetzenecker, Konrad; Woelbing, Florian; Bru?ck, Ju?rgen; Teske, Anna; Valtcheva, Nadejda; Fuchs, Kerstin; Kneilling, Manfred; Park, Ji-hyeon; Kim, Kyu-han; Kim, Kyu-won; Hoffmann, Petra; Krenn, Claus

2011-01-01

113

The role of ethylene and ROS in salinity, heavy metal, and flooding responses in rice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Plant growth and developmental processes as well as abiotic and biotic stress adaptations are regulated by small endogenous signaling molecules. Among these, phytohormones such as the gaseous alkene ethylene and reactive oxygen species (ROS) play an important role in mediating numerous specific growth or cell death responses. While apoplastic ROS are generated by plasma membrane-located respiratory burst oxidase homolog proteins, intracellular ROS are produced mainly in electron transfer chai...

Steffens, Bianka

2014-01-01

114

ROS signalling - specificity is required  

DEFF Research Database (Denmark)

Reactive oxygen species (ROS) production increases in plants under stress. ROS can damage cellular components, but they can also act in signal transduction to help the cell counteract the oxidative damage in the stressed compartment. H2O2 might induce a general stress response, but it does not have the required specificity to selectively regulate nuclear genes required for dealing with localized stress, e.g. in chloroplasts or mitochondria. Here we argue that peptides deriving from proteolytic breakdown of oxidatively damaged proteins have the requisite specificity to act as secondary ROS messengers and regulate source-specific genes and in this way contribute to retrograde ROS signalling during oxidative stress. Likewise, unmodified peptides deriving from the breakdown of redundant proteins could help coordinate organellar and nuclear gene expression

MØller, Ian M; Sweetlove, Lee J

2010-01-01

115

Effect of electroacupuncture to prevent selenite-induced cataract in Wistar rats Efeito da eletro-acupuntura na prevenção da catarata induzida por selenito de sódio em ratos Wistar  

Directory of Open Access Journals (Sweden)

Full Text Available PURPOSE: To investigate whether electroacupuncture can prevent selenite-induced cataract in an experimental model. METHODS: Fifty Wistar rat pups were randomized into 5 groups of 10 animals: Group 1 (control, no procedure was performed; Group 2 (selenite, sodium selenite (30 micromoles/kg body weight was injected subcutaneously between postpartum days 10 to 12; Group 3 (anesthesia received the same dose of selenite and underwent ether inhalation anesthesia during 10 minutes daily for one week; Group 4 (electroacupuncture underwent the same procedure of Group 3, but also receiving electroacupuncture (2 Hz, 50 mA applied to the Neiguan (PC6 and Guangming (GB37 acupoints during the anesthesia period; and Group 5 (Sham underwent the same procedures of Group 4, but needles were applied to non-acupoints. The development of cataract was assessed one week later, and its density was graded by slit lamp biomicroscopy. RESULTS: All control rats lenses (Group 1 were clear. Groups 2, 3 and 5 rats developed more severe cataract or complete opacification. In Group 4 (electroacupuncture, 45% of eyes did not develop cataract while thirty per cent developed less severe cataract than Groups 2, 3 and 5. The between-group difference was statistically significant (pOBJETIVO: Avaliar o efeito da eletro-acupuntura na prevenção da catarata induzida por selenito de sódio em modelo experimental. MÉTODO: Cinqüenta filhotes de ratos Wistar foram randomizados em 5 grupos: no Grupo 1 (Controle, n=10 nenhum procedimento foi realizado. Grupo 2 (Selenito, n=10, selenito de sódio (30 µmoles/kg foi injetado por via subcutânea no décimo dia de vida. No Grupo 3 (Anestesia, n=10, filhotes receberam a mesma dose de selenito e sofreram anestesia inalatória com éter etílico durante 10 minutos diariamente por 1 semana. Grupo 4 (eletro-acupuntura, n=10, os animais sofreram os mesmos procedimentos do Grupo 3, porém também receberam eletro-acupuntura (2 Hz, 50 mA aplicada nos pontos Neiguan (PC 6 e Guangming (GB37 durante o período de anestesia. Grupo 5 (Sham, n=10, os ratos foram submetidos aos mesmos procedimentos que o Grupo 4, porém as agulhas foram aplicadas em pontos falsos. O desenvolvimento da catarata foi avaliado após uma semana por lâmpada de fenda. RESULTADOS: Todos os animais controles (Grupo 1 não desenvolveram catarata. Todos os ratos dos grupos 2, 3 e 5 desenvolveram catarata grave. No Grupo 4 (eletro-acupuntura, 45% dos olhos não desenvolveram catarata e trinta por cento desenvolveram catarata menos grave que aos Grupos 2, 3 e 5. A diferença entre os grupos foi estatisticamente significante (p<0,001. A média do grau de opacificação do cristalino nos Grupos 1 e 4 foi mais baixo que nos Grupos 2, 3 e 5 (p<0,001. CONCLUSÃO: Eletro-acupuntura diminuiu a taxa de formação de catarata induzida por selenito em filhotes de ratos quando as agulhas foram aplicadas em pontos de acupuntura específicos.

Angelino Julio Cariello

2006-06-01

116

Scavenging ROS dramatically increase NMDA receptor whole-cell currents in painted turtle cortical neurons.  

Science.gov (United States)

Oxygen deprivation triggers excitotoxic cell death in mammal neurons through excessive calcium loading via over-activation of N-methyl-d-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. This does not occur in the western painted turtle, which overwinters for months without oxygen. Neurological damage is avoided through anoxia-mediated decreases in NMDA and AMPA receptor currents that are dependent upon a modest rise in intracellular Ca(2+) concentrations ([Ca(2+)]i) originating from mitochondria. Anoxia also blocks mitochondrial reactive oxygen species (ROS) generation, which is another potential signaling mechanism to regulate glutamate receptors. To assess the effects of decreased intracellular [ROS] on NMDA and AMPA receptor currents, we scavenged ROS with N-2-mercaptopropionylglycine (MPG) or N-acetylcysteine (NAC). Unlike anoxia, ROS scavengers increased NMDA receptor whole-cell currents by 100%, while hydrogen peroxide decreased currents. AMPA receptor currents and [Ca(2+)]i concentrations were unaffected by ROS manipulation. Because decreases in [ROS] increased NMDA receptor currents, we next asked whether mitochondrial Ca(2+) release prevents receptor potentiation during anoxia. Normoxic activation of mitochondrial ATP-sensitive potassium (mKATP) channels with diazoxide decreased NMDA receptor currents and was unaffected by subsequent ROS scavenging. Diazoxide application following ROS scavenging did not rescue scavenger-mediated increases in NMDA receptor currents. Fluorescent measurement of [Ca(2+)]i and ROS levels demonstrated that [Ca(2+)]i increases before ROS decreases. We conclude that decreases in ROS concentration are not linked to anoxia-mediated decreases in NMDA/AMPA receptor currents but are rather associated with an increase in NMDA receptor currents that is prevented during anoxia by mitochondrial Ca(2+) release. PMID:25063855

Dukoff, David James; Hogg, David William; Hawrysh, Peter John; Buck, Leslie Thomas

2014-09-15

117

Dexamethasone increases ROS production and T cell suppressive capacity by anti-inflammatory macrophages.  

Science.gov (United States)

Macrophages have been demonstrated to suppress T cell responses by producing reactive oxygen species (ROS) leading to the subsequent induction of T regulatory cells in a ROS-dependent manner. Macrophages may therefore be instrumental in downregulating T cell responses in situations of exacerbated immune responses. Here we investigated the effect of immunosuppressive drugs on ROS production by macrophage subsets and the subsequent effects on T cell activation. Macrophage types 1 and 2 were differentiated with GM-CSF or M-CSF, in presence or absence of dexamethasone, cyclosporine A, FK506, rapamycin, or mycophenolic acid. The ROS producing capacity of fully differentiated Mph was highest in anti-inflammatory Mph2 and not affected by exposure to immunosuppressive drugs. However, presence of rapamycin during Mph2 differentiation decreased the ROS production of these cells. In contrast, other immunosuppressive drugs, with dexamethasone being the most potent, increased the ROS producing capacity of Mph2. Intriguingly although the ROS producing ability of Mph1 was unaffected, dexamethasone strongly increased the ROS producing capabilities of dendritic cells. Both at the mRNA and protein level we found that dexamethasone enhanced the expression of NOX2 protein p47(phox). Functionally, dexamethasone further enhanced the capacity of Mph2 to suppress T cell mediated IFN-? and IL-4 production. In vivo, only in rats with normal ROS production (congenic DA.Ncf1(E3/E3)) it was observed that dexamethasone injection resulted in long-lasting upregulation of ROS production by macrophages and induced higher levels of Treg in a ROS-dependent manner. In conclusion, we show that the anti-inflammatory drug dexamethasone increases the ROS producing capacity of macrophages. PMID:22047959

Kraaij, Marina D; van der Kooij, Sandra W; Reinders, Marlies E J; Koekkoek, Karin; Rabelink, Ton J; van Kooten, Cees; Gelderman, Kyra A

2011-12-01

118

ROS1 Immunohistochemistry for Detection of ROS1-Rearranged Lung Adenocarcinomas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ROS1 gene rearrangements are reported in 1–2% of lung adenocarcinomas (ACA) and are associated with response to the multitargeted tyrosine kinase inhibitor, crizotinib. ROS1 rearrangements can be detected using fluorescence in situ hybridization (FISH) however immunohistochemistry (IHC) for ROS1 protein is a promising alternate screening modality. In this study we examine the correlation between ROS1 IHC and FISH and describe the clinicopathologic characteristics of ROS1-rearranged lung tum...

Sholl, Lynette M.; Sun, Heather; Butaney, Mohit; Zhang, Chengsheng; Lee, Charles; Ja?nne, Pasi A.; Rodig, Scott J.

2013-01-01

119

The role of ethylene and ROS in salinity, heavy metal, and flooding responses in rice.  

Science.gov (United States)

Plant growth and developmental processes as well as abiotic and biotic stress adaptations are regulated by small endogenous signaling molecules. Among these, phytohormones such as the gaseous alkene ethylene and reactive oxygen species (ROS) play an important role in mediating numerous specific growth or cell death responses. While apoplastic ROS are generated by plasma membrane-located respiratory burst oxidase homolog proteins, intracellular ROS are produced mainly in electron transfer chains of mitochondria and chloroplasts. Ethylene accumulates in plants due to physical entrapment or by enhanced ethylene biosynthesis. A major crop that must endure high salt and heavy metal concentrations upon flooding in regions of Asia is rice. Ethylene and ROS have been identified as the major signals that mediate salinity, chromium, and flooding stress in rice. This mini review focuses on (i) what is known about ethylene and ROS level control during these abiotic stresses in rice, (ii) how the two signals mediate growth or death processes, and (iii) feedback mechanisms that in turn regulate ethylene and ROS signaling. PMID:25538719

Steffens, Bianka

2014-01-01

120

ROS-GC interlocked Ca2+-sensor S100B protein signaling in cone photoreceptors: Review  

Directory of Open Access Journals (Sweden)

Full Text Available Photoreceptor rod outer segment membrane guanylate cyclase (ROS-GC is central to visual transduction; it generates cyclic GMP, the second messenger of the photon signal. Photoexcited rhodopsin initiates a biochemical cascade that leads to a drop in the intracellular level of cyclic GMP and closure of cyclic nucleotide gated (CNG ion channels. Recovery of the photoresponse requires resynthesis of cyclic GMP, typically by a pair of ROS-GCs, 1 and 2. In rods, ROS-GCs exist as complexes with GCAPs, which are Ca2+-sensing elements. There is a light-induced fall in intracellular Ca2+. As Ca2+ dissociates from GCAPs in the 20 to 200 nM range, ROS-GC activity rises to quicken the photoresponse recovery. GCAPs then progressively turn down ROS-GC activity as Ca2+ and cyclic GMP levels return to baseline. To date, GCAPs mediate the only known mechanism of ROS-GC regulation in the photoreceptors. However, in mammalian cone outer segments, cone synapses and ON bipolar cells, another Ca2+ sensor protein, S100B, complexes with ROS-GC1 and senses the Ca2+ signal with a K1/2 of 400 nM. Unlike GCAPs, S100B stimulates ROS-GC activity when Ca2+ is bound. Thus, the ROS-GC system in cones functions as a Ca2+ bimodal switch; with rising intracellular Ca2+, its activity is first turned down by GCAPs and then turned up by S100B. This presentation provides a historical perspective on the role of S100B in the photoreceptors, offers a pictorial model for the “bimodal” operation of the ROS-GC switch and projects future tasks that are needed to understand its operation. Some accounts of this review have been adopted from the original publications of these authors.

Rameshwar K Sharma

2014-03-01

 
 
 
 
121

ROS-GC interlocked Ca2+-sensor S100B protein signaling in cone photoreceptors: review  

Science.gov (United States)

Photoreceptor rod outer segment membrane guanylate cyclase (ROS-GC) is central to visual transduction; it generates cyclic GMP, the second messenger of the photon signal. Photoexcited rhodopsin initiates a biochemical cascade that leads to a drop in the intracellular level of cyclic GMP and closure of cyclic nucleotide gated ion channels. Recovery of the photoresponse requires resynthesis of cyclic GMP, typically by a pair of ROS-GCs, 1 and 2. In rods, ROS-GCs exist as complexes with guanylate cyclase activating proteins (GCAPs), which are Ca2+-sensing elements. There is a light-induced fall in intracellular Ca2+. As Ca2+ dissociates from GCAPs in the 20–200 nM range, ROS-GC activity rises to quicken the photoresponse recovery. GCAPs then progressively turn down ROS-GC activity as Ca2+ and cyclic GMP levels return to baseline. To date, GCAPs mediate the only known mechanism of ROS-GC regulation in the photoreceptors. However, in mammalian cone outer segments, cone synapses and ON bipolar cells, another Ca2+ sensor protein, S100B, complexes with ROS-GC1 and senses the Ca2+ signal with a K1/2 of 400 nM. Unlike GCAPs, S100B stimulates ROS-GC activity when Ca2+ is bound. Thus, the ROS-GC system in cones functions as a Ca2+ bimodal switch; with rising intracellular Ca2+, its activity is first turned down by GCAPs and then turned up by S100B. This presentation provides a historical perspective on the role of S100B in the photoreceptors, offers a pictorial model for the “bimodal” operation of the ROS-GC switch and projects future tasks that are needed to understand its operation. Some accounts of this review have been adopted from the original publications of these authors. PMID:24723847

Sharma, Rameshwar K.; Makino, Clint L.; Hicks, David; Duda, Teresa

2014-01-01

122

ROS-GC interlocked Ca(2+)-sensor S100B protein signaling in cone photoreceptors: review.  

Science.gov (United States)

Photoreceptor rod outer segment membrane guanylate cyclase (ROS-GC) is central to visual transduction; it generates cyclic GMP, the second messenger of the photon signal. Photoexcited rhodopsin initiates a biochemical cascade that leads to a drop in the intracellular level of cyclic GMP and closure of cyclic nucleotide gated ion channels. Recovery of the photoresponse requires resynthesis of cyclic GMP, typically by a pair of ROS-GCs, 1 and 2. In rods, ROS-GCs exist as complexes with guanylate cyclase activating proteins (GCAPs), which are Ca(2+)-sensing elements. There is a light-induced fall in intracellular Ca(2+). As Ca(2+) dissociates from GCAPs in the 20-200 nM range, ROS-GC activity rises to quicken the photoresponse recovery. GCAPs then progressively turn down ROS-GC activity as Ca(2+) and cyclic GMP levels return to baseline. To date, GCAPs mediate the only known mechanism of ROS-GC regulation in the photoreceptors. However, in mammalian cone outer segments, cone synapses and ON bipolar cells, another Ca(2+) sensor protein, S100B, complexes with ROS-GC1 and senses the Ca(2+) signal with a K1/2 of 400 nM. Unlike GCAPs, S100B stimulates ROS-GC activity when Ca(2+) is bound. Thus, the ROS-GC system in cones functions as a Ca(2+) bimodal switch; with rising intracellular Ca(2+), its activity is first turned down by GCAPs and then turned up by S100B. This presentation provides a historical perspective on the role of S100B in the photoreceptors, offers a pictorial model for the "bimodal" operation of the ROS-GC switch and projects future tasks that are needed to understand its operation. Some accounts of this review have been adopted from the original publications of these authors. PMID:24723847

Sharma, Rameshwar K; Makino, Clint L; Hicks, David; Duda, Teresa

2014-01-01

123

Synthesis, characterization and ROS-mediated cytotoxic action of novel (S,S)-1,3-propanediamine-N,N'-di-2-(3-cyclohexyl)propanoic acid and corresponding esters.  

Science.gov (United States)

This study involves the synthesis and characterization of novel cyclohexyl 1,3-propanediamine-N,N'-diacetate molecules as well as investigation of their cytotoxic action. New acid 1a was synthesized by reaction between (S)-2-amino-3-cyclohexylpropanoic acid and 1,3-dibromopropane, while the esters (1b-1e) derived from this acid were obtained by reaction of the corresponding absolute alcohol, thionyl chloride and synthesized acid. All compounds were characterized by IR, ESI-MS, ((1)H, (13)C and HSQC) NMR spectroscopy and elemental analysis. The cytotoxic activity of all compounds was tested on several tumour cell lines: human (U251) and rat (C6) glioma, human promyelocytic leukaemia (HL-60), human neuroblastoma (SHSY-5Y) and mouse fibrosarcoma (L929) as well as primary rat astrocytes. The present study reveals potent antitumour activity of novel purely organic compounds (1a-1e), which was most pronounced in human glioma (U251) cells. The esterification is required for the novel compounds' cytotoxic action since the n-butyl ester 1e was the most efficient compound. Importantly, n-butyl ester 1e was more toxic to glioma cells in comparison to rat astrocytes, with 24-h IC50 values lower than those for cisplatin. n-Butyl ester 1e induced production of reactive oxygen species (ROS) and caused an oxidative-stress-derived accumulation of glioma cells in the G0/G1 phase of the cell cycle, as well as caspase activation and DNA fragmentation, suggesting that apoptosis induction plays an important role in the novel compounds' antiglioma action. PMID:24836201

Savi?, Aleksandar; Misirli?-Den?i?, Sonja; Dulovi?, Marija; Mihajlovi?-Lali?, Ljiljana E; Jovanovi?, Maja; Grguri?-Šipka, Sanja; Markovi?, Ivanka; Sabo, Tibor J

2014-06-01

124

Overview on how oncogenic Kras promotes pancreatic carcinogenesis by inducing low intracellular ROS levels.  

Science.gov (United States)

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease without clearly known disease causes. Recent epidemiological and animal studies suggest that the supplementation of dietary antioxidants (e.g., vitamins C and E) decreases cancer risk, implying that increased reactive oxygen species (ROS) may play a role in pancreatic carcinogenesis. However, oncogenic Kras mutations (e.g., Kras(G12D)), which are present in more than 90% of PDAC, have been proven to foster low intracellular ROS levels. Here, oncogenic Kras activates expression of a series of anti-oxidant genes via Nrf2 (nuclear factor, erythroid derived 2, like 2) and also mediates an unusual metabolic pathway of glutamine to generate NADPH. This can then be used as the reducing power for ROS detoxification, leading collectively to low ROS levels in pancreatic pre-neoplastic cells and in cancer cells. In adult stem cells and cancer stem cells, low ROS levels have been associated with the formation of a proliferation-permissive intracellular environment and with perseverance of self-renewal capacities. Therefore, it is conceivable that low intracellular ROS levels may contribute significantly to oncogenic Kras-mediated PDAC formation. PMID:24062691

Kong, Bo; Qia, Chengjia; Erkan, Mert; Kleeff, Jörg; Michalski, Christoph W

2013-01-01

125

Overview on how oncogenic Kras promotes pancreatic carcinogenesis by inducing low intracellular ROS levels  

Directory of Open Access Journals (Sweden)

Full Text Available Pancreatic ductal adenocarcinoma (PDAC is a devastating disease without clearly known disease causes. Recent epidemiological and animal studies suggest that the supplementation of dietary antioxidants (e.g. vitamins C and E decreases cancer risk, implying that increased reactive oxygen species (ROS may play a role in pancreatic carcinogenesis. However, oncogenic Kras mutations (e.g. KrasG12D, which are present in more than 90% of PDAC, have been proven to foster low intracellular ROS levels. Here, oncogenic Kras activates expression of a series of anti-oxidant genes via Nrf2 (nuclear factor, erythroid derived 2, like 2 and also mediates an unusual metabolic pathway of glutamine to generate NADPH. This can then be used as the reducing power for ROS detoxification, leading collectively to low ROS levels in pancreatic pre-neoplastic cells and in cancer cells. In adult stem cells and cancer stem cells, low ROS levels have been associated with the formation of a proliferation-permissive intracellular environment and with perseverance of self-renewal capacities. Therefore, it is conceivable that low intracellular ROS levels may contribute significantly to oncogenic Kras-mediated PDAC formation.

ChristophWMichalski

2013-09-01

126

PERK is required at the ER-mitochondrial contact sites to convey apoptosis after ROS-based ER stress.  

Science.gov (United States)

Endoplasmic reticulum stress is emerging as an important modulator of different pathologies and as a mechanism contributing to cancer cell death in response to therapeutic agents. In several instances, oxidative stress and the onset of endoplasmic reticulum (ER) stress occur together; yet, the molecular events linking reactive oxygen species (ROS) to ER stress-mediated apoptosis are currently unknown. Here, we show that PERK (RNA-dependent protein kinase (PKR)-like ER kinase), a key ER stress sensor of the unfolded protein response, is uniquely enriched at the mitochondria-associated ER membranes (MAMs). PERK(-/-) cells display disturbed ER morphology and Ca(2+) signaling as well as significantly weaker ER-mitochondria contact sites. Re-expression of a kinase-dead PERK mutant but not the cytoplasmic deletion mutant of PERK in PERK(-/-) cells re-establishes ER-mitochondria juxtapositions and mitochondrial sensitization to ROS-mediated stress. In contrast to the canonical ER stressor thapsigargin, during ROS-mediated ER stress, PERK contributes to apoptosis twofold by sustaining the levels of pro-apoptotic C/EBP homologous protein (CHOP) and by facilitating the propagation of ROS signals between the ER and mitochondria through its tethering function. Hence, this study reveals an unprecedented role of PERK as a MAMs component required to maintain the ER-mitochondria juxtapositions and propel ROS-mediated mitochondrial apoptosis. Furthermore, it suggests that loss of PERK may cause defects in cell death sensitivity in pathological conditions linked to ROS-mediated ER stress. PMID:22705852

Verfaillie, T; Rubio, N; Garg, A D; Bultynck, G; Rizzuto, R; Decuypere, J-P; Piette, J; Linehan, C; Gupta, S; Samali, A; Agostinis, P

2012-11-01

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Calyculin A causes sensitization to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis by ROS-mediated down-regulation of cellular FLICE-inhibiting protein (c-FLIP) and by enhancing death receptor 4 mRNA stabilization.  

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Calyculin A (Cal A) is a serine/threonine phosphatase inhibitor that is capable of inducing apoptosis in cancer cells. In this study, we examined whether Cal A could modulate TRAIL-induced apoptosis in human renal carcinoma-derived Caki cells. Our results show that Cal A is capable of sensitizing Caki cells to TRAIL-induced apoptosis, as well as U2OS human osteosarcoma cells and A549 human lung adenocarcinoma epithelial cells. Cal A increases intracellular ROS production and down-regulates c-FLIP(L) expression. Interestingly, the down-regulation of protein phosphatase 1 (PP1) by PP1 siRNA also reduced c-FLIP(L) expression via reactive oxygen species production. Furthermore, Cal A induced death receptor 4 (DR4) mRNA and protein expression by enhancing DR4 mRNA stability. We also found that PP4 siRNA up-regulated DR4 mRNA and protein expression. Collectively, our results suggest that Cal A could enhance TRAIL-mediated apoptosis via the down-regulation of c-FLIP(L) and the up-regulation of DR4 in human renal cell carcinoma cell line Caki. PMID:22911475

Woo, Seon Min; Min, Kyoung-jin; Kwon, Taeg Kyu

2012-11-01

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Natural daucane esters induces apoptosis in leukaemic cells through ROS production.  

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Continuing our research on antiproliferative agents from plants, we extended our interest on further compounds isolated from Ferula communis and Ferulago campestris. One new daucane (DE-20) and one new phenol derivative (PH-3) were isolated and characterized in addition to six daucane, three coumarins and four simple phenolics. The cytotoxic activity was evaluated against a panel of six human tumor cell lines. The derivative DE-17 that resulted moderately active on all the studied cell lines was studied to evaluate its possible mechanism of action. DE-17 was able to induce apoptosis in a time and concentration-dependent manner in SEM and Jurkat cell lines. We observed that DE-17 just after 1h of treatment increased the reactive oxygen species (ROS) production and that the co-incubation of DE-17 with ROS scavengers significantly increased cell viability suggesting that ROS-mediated downstream signaling is essential for the antiproliferative effects of DE-17. At later times of incubation DE-17 induced mitochondrial depolarization, as well as caspase-3 and -9 activation suggesting that apoptosis follow the mitochondrial pathway. Concomitantly to ROS induction, a remarkable decrease of mRNA expression of several antioxidant enzymes and intracellular GSH content was detected in treated cells compared to controls further indicative of oxidative stress. Taken together our results showed for the first time that daucane esters induces apoptotic cell death through a ROS-mediated mechanism in human leukemia cells. PMID:25294094

Dall'Acqua, Stefano; Linardi, Maria Antonella; Bortolozzi, Roberta; Clauser, Maria; Marzocchini, Sara; Maggi, Filippo; Nicoletti, Marcello; Innocenti, Gabbriella; Basso, Giuseppe; Viola, Giampietro

2014-12-01

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Influenza virus replication in lung epithelial cells depends on redox-sensitive pathways activated by NOX4-derived ROS.  

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An overproduction of reactive oxygen species (ROS) mediated by NADPH oxidase 2 (NOX2) has been related to airway inflammation typical of influenza infection. Virus-induced oxidative stress may also control viral replication, but the mechanisms underlying ROS production, as well as their role in activating intracellular pathways and specific steps of viral life cycle under redox control have to be fully elucidated. In this study, we demonstrate that influenza A virus infection of lung epithelial cells causes a significant ROS increase that depends mainly on NOX4, which is upregulated at both mRNA and protein levels, while the expression of NOX2, the primary source of ROS in inflammatory cells, is downregulated. Inhibition of NOX4 activity through chemical inhibitors or RNA silencing blocks the ROS increase, prevents MAPK phosphorylation, and inhibits viral ribonucleoprotein (vRNP) nuclear export and viral release. Overall these data, obtained in cell lines and primary culture, describe a so far unrecognized role for NOX4-derived ROS in activating redox-regulated intracellular pathways during influenza virus infection and highlight their relevance in controlling specific steps of viral replication in epithelial cells. Pharmacological modulation of NOX4-mediated ROS production may open the way for new therapeutic approaches to fighting influenza by targeting cell and not the virus. PMID:25154738

Amatore, Donatella; Sgarbanti, Rossella; Aquilano, Katia; Baldelli, Sara; Limongi, Dolores; Civitelli, Livia; Nencioni, Lucia; Garaci, Enrico; Ciriolo, Maria Rosa; Palamara, Anna Teresa

2015-01-01

130

Influenza virus replication in lung epithelial cells depends on redox-sensitive pathways activated by NOX4-derived ROS  

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An overproduction of reactive oxygen species (ROS) mediated by NADPH oxidase 2 (NOX2) has been related to airway inflammation typical of influenza infection. Virus-induced oxidative stress may also control viral replication, but the mechanisms underlying ROS production, as well as their role in activating intracellular pathways and specific steps of viral life cycle under redox control have to be fully elucidated. In this study, we demonstrate that influenza A virus infection of lung epithelial cells causes a significant ROS increase that depends mainly on NOX4, which is upregulated at both mRNA and protein levels, while the expression of NOX2, the primary source of ROS in inflammatory cells, is downregulated. Inhibition of NOX4 activity through chemical inhibitors or RNA silencing blocks the ROS increase, prevents MAPK phosphorylation, and inhibits viral ribonucleoprotein (vRNP) nuclear export and viral release. Overall these data, obtained in cell lines and primary culture, describe a so far unrecognized role for NOX4-derived ROS in activating redox-regulated intracellular pathways during influenza virus infection and highlight their relevance in controlling specific steps of viral replication in epithelial cells. Pharmacological modulation of NOX4-mediated ROS production may open the way for new therapeutic approaches to fighting influenza by targeting cell and not the virus. PMID:25154738

Amatore, Donatella; Sgarbanti, Rossella; Aquilano, Katia; Baldelli, Sara; Limongi, Dolores; Civitelli, Livia; Nencioni, Lucia; Garaci, Enrico; Ciriolo, Maria Rosa; Palamara, Anna Teresa

2015-01-01

131

Anticancer effect of calycopterin via PI3K/Akt and MAPK signaling pathways, ROS-mediated pathway and mitochondrial dysfunction in hepatoblastoma cancer (HepG2) cells.  

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Calycopterin is a flavonoid compound isolated from Dracocephalum kotschyi that has multiple medical uses, as an antispasmodic, analgesic, anti-hyperlipidemic, and immunomodulatory agents. However, its biological activity and the mechanism of action are poorly investigated. Herein, we investigated the apoptotic effect of calycopterin against the human hepatoblastoma cancer cell (HepG2) line. We discovered that calycopterin-treated HepG2 cells were killed off by apoptosis in a dose-dependent manner within 24 h, and was characterized by the appearance of nuclear shrinkage, cleavage of poly (ADP-ribose) polymerase and DNA fragmentation. Calycopterin treatment also affected HepG2 cell viability: (a) by inhibiting cell cycle progression at the G2/M transition leading to growth arrest and apoptosis; (b) by decreasing the expression of mitotic kinase cdc2, mitotic phosphatase cdc25c, mitotic cyclin B1, and apoptotic factors pro-caspases-3 and -9; and (c) increasing the levels of mitochondrial apoptotic-related proteins, intracellular levels of reactive oxygen species, and nitric oxide. We further examined the phosphorylation of extracellular signal-related kinase (ERK 1/2), c-Jun N-terminal kinase, and p-38 mitogen-activated protein kinases (MAPKs) and found they all were significantly increased in HepG2 cells treated with calycopterin. Interestingly, we discovered that treated cells had significantly lower Akt phosphorylation. This mode of action for calycopterin in our study provides strong support that inhibition of PI3K/Akt and activation of MAPKs are pivotal in G2/M cell cycle arrest and apoptosis of human hepatocarcinoma cells mediated by calycopterin. PMID:25060910

Esmaeili, Mohammad Ali; Farimani, Mahdi Moridi; Kiaei, Mahmoud

2014-12-01

132

ROS generation via NOX4 and its utility in the cytological diagnosis of urothelial carcinoma of the urinary bladder  

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Full Text Available Abstract Background Reactive oxygen species (ROS production via NADPH oxidase (NOX contributes to various types of cancer progression. In the present research, we examined the pathobiological role of NADPH oxidase (NOX4-mediated generation of reactive oxygen species (ROS in urothelial carcinoma (UC of the urinary bladder, and demonstrated the utility of ROS labeling in urine cytology. Methods NOX4 gene was silenced in vivo and in vitro by NOX4 siRNA transfection with or without atlocollagen. Cell cycle and measurement of ROS were analyzed by flowcytometry. Orthotopic implantation animal model was used in vivo experiment. NOX4 expression in urothelial carcinoma cells was observed by immunohistochemical analysis using surgical specimens of human bladder cancer. Urine cytology was performed after treatment with ROS detection reagents in addition to Papanicolaou staining. Results NOX4 was overexpressed in several UC cell lines and the NOX inhibitor, diphenylene iodonium reduced intracellular ROS and induced p16-dependent cell cycle arrest at the G1 phase. Moreover, silencing of NOX4 by siRNA significantly reduced cancer cell growth in vivo as assessed in an orthotopic mouse model. Immunohistochemistry demonstrated high expression of NOX4 in low grade/non-invasive and high grade/invasive UC including precancerous lesions such as dysplasia but not in normal urothelium. Then, we assessed the usefulness of cytological analysis of ROS producing cells in urine (ROS-C. Urine samples obtained from UC cases and normal controls were treated with fluorescent reagents labeling the hydrogen peroxide/superoxide anion and cytological atypia of ROS positive cells were analyzed. As a result, the sensitivity for detection of low grade, non-invasive UC was greatly increased (35% in conventional cytology (C-C vs. 75% in ROS-C, and the specificity was 95%. Through ROS-C, we observed robust improvement in the accuracy of follow-up urine cytology for cases with previously diagnosed UC, especially in those with low grade/non-invasive cancer recurrence (0% in C-C vs. 64% in ROS-C. Conclusions This is the first report demonstrating that ROS generation through NOX4 contributes to an early step of urothelial carcinogenesis and cancer cell survival. In addition, cytology using ROS labeling could be a useful diagnostic tool in human bladder cancer.

Fujimoto Kiyohide

2011-10-01

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Microcystin-LR-Caused ROS generation involved in p38 activation and tau hyperphosphorylation in neuroendocrine (PC12) cells.  

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Microcystin-LR (MC-LR), a potent specific hepatotoxin produced by cyanobacteria, has recently been reported to show neurotoxicity. Our previous study demonstrated that MC-LR caused the reorganization of cytoskeleton architectures and hyperphosphorylation of the cytoskeletal-associated proteins tau and HSP27 in neuroendocrine PC12 cell line by direct PP2A inhibition and indirect p38 mitogen-activated protein kinase (MAPK) activation. It has been shown that oxidative stress is extensively associated with MC-LR toxicity, mainly resulting from an excessive production of reactive oxygen species (ROS). However, the mechanisms by which ROS mediates the cytotoxic action of MC-LR are unclear. In the present study, we investigated whether ROS might play a critical role in MC-LR-induced hyperphosphorylation of microtubule-associated protein tau and the activation of the MAPKs in PC12 cell line. The results showed that MC-LR had time- and concentration-dependent effects on ROS generation, p38-MAPK activation and tau phosphorylation. The time-course studies indicated similar biphasic changes in ROS generation and tau hyperphosphorylation, which started to increase within 1 h and reached the maximum level at 3 h followed by a decrease after prolonged treatment. Furthermore, pretreatment with the antioxidants, N-acetylcysteine and vitamin C, significantly decreased MC-LR-induced ROS generation and effectively attenuated p38-MAPK activation as well as tau hyperphosphorylation. Taken together, these findings suggest that ROS generation triggered by MC-LR is a key intracellular event that contributes to an induction of p38-MAPK activation and tau phosphorylation, and that blockade of this ROS-mediated redox-sensitive signal cascades may attenuate the toxic effects of MC-LR. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 366-374, 2015. PMID:24142891

Meng, Guanmin; Liu, Jinghui; Lin, Shuyan; Guo, Zonglou; Xu, Lihong

2015-03-01

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Contribution of mitochondrial network dynamics to intracellular ROS signaling  

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Oxidative stresses can induce rapid depolarization of inner mitochondrial membrane potential and subsequent impairment of oxidative phosphorylation. Damaged mitochondria produce more reactive oxygen species (ROS), particularly the superoxide anion (O2-) and hydrogen peroxide (H2O2), which potentiate mitochondria-driven ROS propagation, so-called ROS-induced ROS release (RIRR), via activation of an inter-mitochondrial signaling network. In this context, mitochondrial network dynamics, such as ...

Park, Junseong; Choi, Chulhee

2012-01-01

135

Mitochondrial ROS in the prohypertensive immune response  

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In the past decade, it has become clear that reactive oxygen species (ROS) and inflammation play an important role in the development of hypertension. Scavenging of mitochondrial superoxide and blocking either IL-17 or tumor necrosis factor-? (TNF-?) attenuates hypertension. T-cells, critical for development of hypertension, once activated intensively produce cytokines, proliferate, and differentiate. Thus T-cell activation leads to expanded energy demand. To fulfill these needs, T-cells th...

Nazarewicz, Rafal R.; Dikalov, Sergey I.

2013-01-01

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RAGE-Induced Cytosolic ROS Promote Mitochondrial Superoxide Generation in Diabetes  

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Damaged mitochondria generate an excess of superoxide, which may mediate tissue injury in diabetes. We hypothesized that in diabetic nephropathy, advanced glycation end-products (AGEs) lead to increases in cytosolic reactive oxygen species (ROS), which facilitate the production of mitochondrial superoxide. In normoglycemic conditions, exposure of primary renal cells to AGEs, transient overexpression of the receptor for AGEs (RAGE) with an adenoviral vector, and infusion of AGEs to healthy rod...

Coughlan, Melinda T.; Thorburn, David R.; Penfold, Sally A.; Laskowski, Adrienne; Harcourt, Brooke E.; Sourris, Karly C.; Tan, Adeline L. Y.; Fukami, Kei; Thallas-bonke, Vicki; Nawroth, Peter P.; Brownlee, Michael; Bierhaus, Angelika; Cooper, Mark E.; Forbes, Josephine M.

2009-01-01

137

Map17, a ROS-dependent oncogene  

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Full Text Available MAP17 is a small 17 kDa non-glycosylated membrane protein previously identified as being overexpressed in carcinomas. Breast tumor cells that overexpress MAP17 show an increased tumoral phenotype with enhanced proliferative capabilities both in the presence or the absence of contact inhibition, decreased apoptotic sensitivity and increased migration. MAP17-expressing clones also grow better in nude mice. The increased malignant cell behavior induced by MAP17 is associated with an increase in reactive oxygen species, ROS, production, and the treatment of MAP17-expressing cells with antioxidants results in a reduction in the tumorigenic properties of these cells. The MAP17-dependent increase in ROS and tumorigenesis relies on its PDZ-binding domain because disruption of this sequence by point mutations abolishes the ability of MAP17 to enhance ROS production and tumorigenesis. MAP17 is overexpressed in a great variety of human carcinomas, including breast tumors. Immunohistochemical analysis of MAP17 during cancer progression demonstrates that overexpression of the protein strongly correlates with tumoral progression. Generalized MAP17 overexpression in human carcinomas indicates that MAP17 can be a good marker for tumorigenesis and, especially, for malignant progression.

AmancioCarnero

2012-09-01

138

Particulate matter exposure exacerbates high glucose-induced cardiomyocyte dysfunction through ROS generation.  

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Diabetes mellitus and fine particulate matter from diesel exhaust (DEP) are both important contributors to the development of cardiovascular disease (CVD). Diabetes mellitus is a progressive disease with a high mortality rate in patients suffering from CVD, resulting in diabetic cardiomyopathy. Elevated DEP levels in the air are attributed to the development of various CVDs, presumably since fine DEP (rat ventricular myocytes exposed overnight to fine DEP (0.1 µg/ml), and/or high glucose (HG, 25.5 mM). Our hypothesis was that DEP exposure exacerbates contractile dysfunction via ROS generation in cardiomyocytes exposed to HG. Ventricular myocytes were isolated from male adult Sprague-Dawley rats cultured overnight and sarcomeric contractile properties were evaluated, including: peak shortening normalized to baseline (PS), time-to-90% shortening (TPS(90)), time-to-90% relengthening (TR(90)) and maximal velocities of shortening/relengthening (±dL/dt), using an IonOptix field-stimulator system. ROS generation was determined using hydroethidine/ethidium confocal microscopy. We found that DEP exposure significantly increased TR(90), decreased PS and ±dL/dt, and enhanced intracellular ROS generation in myocytes exposed to HG. Further studies indicated that co-culture with antioxidants (0.25 mM Tiron and 0.5 mM N-Acetyl-L-cysteine) completely restored contractile function in DEP, HG and HG+DEP-treated myocytes. ROS generation was blocked in HG-treated cells with mitochondrial inhibition, while ROS generation was blocked in DEP-treated cells with NADPH oxidase inhibition. Our results suggest that DEP exacerbates myocardial dysfunction in isolated cardiomyocytes exposed to HG-containing media, which is potentially mediated by various ROS generation pathways. PMID:21850256

Zuo, Li; Youtz, Dane J; Wold, Loren E

2011-01-01

139

Oncogene-induced Nrf2 transcription promotes ROS detoxification and tumorigenesis  

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Reactive oxygen species (ROS) are mutagenic and may thereby promote cancer1. Normally, ROS levels are tightly controlled by an inducible antioxidant program that responds to cellular stressors and is predominantly regulated by the transcription factor Nrf2 and its repressor protein Keap12-5. In contrast to the acute physiological regulation of Nrf2, in neoplasia there is evidence for increased basal activation of Nrf2. Indeed, somatic mutations that disrupt the Nrf2-Keap1 interaction to stabilize Nrf2 and increase the constitutive transcription of Nrf2 target genes were recently identified, suggesting that enhanced ROS detoxification and additional Nrf2 functions may in fact be pro-tumorigenic6. Here, we investigated ROS metabolism in primary murine cells following the expression of endogenous oncogenic alleles of K-Ras, B-Raf and Myc, and find that ROS are actively suppressed by these oncogenes. K-RasG12D, B-RafV619E and MycERT2 each increased the transcription of Nrf2 to stably elevate the basal Nrf2 antioxidant program and thereby lower intracellular ROS and confer a more reduced intracellular environment. Oncogene-directed increased expression of Nrf2 is a novel mechanism for the activation of the Nrf2 antioxidant program, and is evident in primary cells and tissues of mice expressing K-RasG12D and B-RafV619E, and in human pancreatic cancer. Furthermore, genetic targeting of the Nrf2 pathway impairs K-RasG12D-induced proliferation and tumorigenesis in vivo. Thus, the Nrf2 antioxidant and cellular detoxification program represents a previously unappreciated mediator of oncogenesis. PMID:21734707

DeNicola, Gina M.; Karreth, Florian A.; Humpton, Timothy J.; Gopinathan, Aarthi; Wei, Cong; Frese, Kristopher; Mangal, Dipti; Yu, Kenneth H.; Yeo, Charles J.; Calhoun, Eric S.; Scrimieri, Francesca; Winter, Jordan M.; Hruban, Ralph H.; Iacobuzio-Donahue, Christine; Kern, Scott E.; Blair, Ian A.; Tuveson, David A.

2012-01-01

140

Mitochondrial ROS govern the LPS-induced pro-inflammatory response in microglia cells by regulating MAPK and NF-?B pathways.  

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Activation of microglia cells in the brain contributes to neurodegenerative processes promoted by many neurotoxic factors such as pro-inflammatory cytokines and nitric oxide (NO). Reactive oxygen species (ROS) actively affect microglia-associated neurodegenerative diseases through their role as pro-inflammatory molecules and modulators of pro-inflammatory processes. Although the ROS which involved in microglia activation are thought to be generated primarily by NADPH oxidase (NOX) and involved in the immune response, mitochondrial ROS have also been proposed as important regulators of the inflammatory response in the innate immune system. However, the role of mitochondrial ROS in microglial activation has yet to be fully elucidated. In this study, we demonstrate that inhibition of mitochondrial ROS by treatment with Mito-TEMPO effectively suppressed the level of mitochondrial and intracellular ROS. Mito-TEMPO treatment also significantly prevented LPS-induced increase in the TNF-?, IL-1?, IL-6, iNOS and Cox-2 in BV-2 and primary microglia cells. Furthermore, LPS-induced suppression of mitochondrial ROS generation not only affected LPS-stimulated activation of MAPKs, including ERK, JNK, and p38, but also regulated I?B activation and NF-?B nuclear localization. These results indicate that mitochondria constitute a major source of ROS generation in LPS-mediated activated microglia cells. Additionally, suppression of LPS-induced mitochondrial ROS plays a role in modulating the production of pro-inflammatory mediators by preventing MAPK and NF-?B activation in microglia cells. Our findings suggest that a potential strategy in the development of therapy for inflammation-associated degenerative neurological diseases involves targeting the regulation of mitochondrial ROS in microglial cells. PMID:25459294

Park, Junghyung; Min, Ju-Sik; Kim, Bokyung; Chae, Un-Bin; Yun, Jong Won; Choi, Myung-Sook; Kong, Il-Keun; Chang, Kyu-Tae; Lee, Dong-Seok

2015-01-01

 
 
 
 
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PARP-1 hyperactivation and reciprocal elevations in intracellular Ca2+ during ROS-induced nonapoptotic cell death.  

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The generation of reactive oxygen species (ROS) has been implicated in the pathogenesis of renal ischemia/reperfusion injury, and many other pathological conditions. DNA strand breaks caused by ROS lead to the activation of poly(ADP-ribose)polymerase-1 (PARP-1), the excessive activation of which can result in cell death. We have utilized a model in which 2,3,5-tris(glutathion-S-yl)hydroquinone (TGHQ), a nephrotoxic and nephrocarcinogenic metabolite of hydroquinone, causes ROS-dependent cell death in human renal proximal tubule epithelial cells (HK-2), to further elucidate the role of PARP-1 in ROS-dependent cell death. TGHQ-induced ROS generation, DNA strand breaks, hyperactivation of PARP-1, rapid depletion of nicotinamide adenine dinucleotide (NAD), elevations in intracellular Ca(2+) concentrations, and subsequent nonapoptotic cell death in both a PARP- and Ca(2+)-dependent manner. Thus, inhibition of PARP-1 with PJ34 completely blocked TGHQ-mediated accumulation of poly(ADP-ribose) polymers and NAD consumption, and delayed HK-2 cell death. In contrast, chelation of intracellular Ca(2+) with BAPTA completely abrogated TGHQ-induced cell death. Ca(2+) chelation also attenuated PARP-1 hyperactivation. Conversely, inhibition of PARP-1 modulated TGHQ-mediated changes in Ca(2+) homeostasis. Interestingly, PARP-1 hyperactivation was not accompanied by the translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus, a process usually associated with PARP-dependent cell death. Thus, pathways coupling PARP-1 hyperactivation to cell death are likely to be context-dependent, and therapeutic strategies designed to target PARP-1 need to recognize such variability. Our studies provide new insights into PARP-1-mediated nonapoptotic cell death, during which PARP-1 hyperactivation and elevations in intracellular Ca(2+) are reciprocally coupled to amplify ROS-induced nonapoptotic cell death. PMID:24752504

Zhang, Fengjiao; Xie, Ruiye; Munoz, Frances M; Lau, Serrine S; Monks, Terrence J

2014-07-01

142

Amorphous nanosilica induce endocytosis-dependent ROS generation and DNA damage in human keratinocytes  

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Full Text Available Abstract Background Clarifying the physicochemical properties of nanomaterials is crucial for hazard assessment and the safe application of these substances. With this in mind, we analyzed the relationship between particle size and the in vitro effect of amorphous nanosilica (nSP. Specifically, we evaluated the relationship between particle size of nSP and the in vitro biological effects using human keratinocyte cells (HaCaT. Results Our results indicate that exposure to nSP of 70 nm diameter (nSP70 induced an elevated level of reactive oxygen species (ROS, leading to DNA damage. A markedly reduced response was observed using submicron-sized silica particles of 300 and 1000 nm diameter. In addition, cytochalasin D-treatment reduced nSP70-mediated ROS generation and DNA damage, suggesting that endocytosis is involved in nSP70-mediated cellular effects. Conclusions Thus, particle size affects amorphous silica-induced ROS generation and DNA damage of HaCaT cells. We believe clarification of the endocytosis pathway of nSP will provide useful information for hazard assessment as well as the design of safer forms of nSPs.

Hirai Toshiro

2011-01-01

143

Cilostazol Enhances Oxidative Glucose Metabolism in Both Neurons and Astroglia without Increasing Ros Production  

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Full Text Available Cilostazol, a potent inhibitor of type 3 phosphodiesterase (PDE3, has recently been reported to exert neuroprotective effects during acute cerebral ischemic injury. These effects are, at least in part, mediated by the inhibition of oxidative cell death. However, the effects of cilostazol on glucose metabolism in brain cells have not been determined. In the present study, we examined the effects of cilostazol on the oxidative metabolism of glucose and the resultant formation of reactive oxygen species (ROS in cultured neurons and astroglia. Cultures of neurons or astroglia were prepared from Sprague-Dawley rats. The cells were treated with cilostazol (0 – 30 ?M for 48 hours prior to the assay. L-[U-14C]lactate ([14C]lactate or [1-14C]pyruvate ([14C]pyruvate oxidation was measured. ROS production was determined using an H2DCFDA assay with a microplate reader. Forty-eight hours of exposure to cilostazol resulted in dose-dependent increases in [14C]lactate and [14C]pyruvate oxidation in both the neurons and astroglia. Dibutyryl cyclic AMP (0 – 0.5 mM also increased [14C]lactate oxidation, indicating cAMP-mediated PDH activation. In contrast, free radical formation was not affected by cilostazol in either the neurons or astroglia. Cilostazol enhanced the oxidative metabolism of glucose in both neurons and astroglia, while it did not augment ROS production.

Shinichi Takahashi

2011-10-01

144

Mitochondrial ROS potentiates indirect activation of the AIM2 inflammasome  

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Full Text Available Activation of the inflammasome is important for the detection and clearance of cytosolic pathogens. In contrast to avirulent F. novicida (Fn, infection with virulent F. tularensis ssp tularensis does not trigger activation of the host AIM2 inflammasome. Here we show that differential activation of AIM2 following Francisella infection is due to sensitivity of each isolate to reactive oxygen species (ROS. ROS present at the outset of Fn infection contributes to activation of the AIM2 inflammasome, independent of NLRP3 and NADPH oxidase. Rather, mitochondrial ROS (mROS is critical for Fn stimulation of the inflammasome. This study represents the first demonstration of the importance of mROS in the activation of the AIM2 inflammasome by bacteria. Our results also demonstrate that bacterial resistance to mROS is a mechanism of virulence for early evasion of detection by the host.

CatharineBosio

2014-08-01

145

Benzoquinone activates the ERK/MAPK signaling pathway via ROS production in HL-60 cells  

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Benzene (BZ) is a class I carcinogen and its oxidation to reactive intermediates is a prerequisite of hematoxicity and myelotoxicity. The generated metabolites include hydroquinone, which is further oxidized to the highly reactive 1,4-benzoquinone (BQ) in bone marrow. Therefore, we explored the mechanisms underlying BQ-induced HL-60 cell proliferation by studying the role of BQ-induced reactive oxygen species (ROS) in the activation of the ERK-MAPK signaling pathway. BQ treatment (0.01-30 ?M) showed that doses below 10 ?M did not significantly reduce viability. ROS production after 3 ?M BQ treatment increased threefold; however, catalase addition reduced ROS generation to basal levels. FACS analysis showed that BQ induced a fivefold increase in the proportion of cells in S-phase. We also observed a high proportion of Bromodeoxyuridine (BrdU) stained cells, indicating a higher DNA synthesis rate. BQ also produced rapid and prolonged phosphorylation of ERK1/2 proteins. Simultaneous treatment with catalase or PD98059, a potent MEK protein inhibitor, reduced cell recruitment into the S-phase and also abolished the ERK1/2 protein phosphorylation induced by BQ, suggesting that MEK/ERK is an important pathway involved in BQ-induced ROS mediated proliferation. The prolonged activation of ERK1/2 contributes to explain the increased S-phase cell recruitment and to understand the leukemogenic processes associated with exposure to benzene metabolites. Thus, the possible mechan metabolites. Thus, the possible mechanism by which BQ induce HL-60 cells to enter the cell cycle and proliferate is linked to ROS production and its growth promoting effects by specific activation of regulating genes known to be activated by redox mechanisms

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ROS-dependent anticandidal activity of zinc oxide nanoparticles synthesized by using egg albumen as a biotemplate  

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Zinc oxide nanoparticles (ZnO NPs) have attracted great attention because of their superior optical properties and wide application in biomedical science. However, little is known about the anticandidal activity of ZnO NPs against Candida albicans (C. albicans). This study was designed to develop the green approach to synthesize ZnO NPs using egg white (denoted as EtZnO NPs) and investigated its possible mechanism of antimicrobial activity against C. albicans 077. It was also notable that anticandidal activity of EtZnO NPs is correlated with reactive oxygen species (ROS) production in a dose dependent manner. Protection of histidine against ROS clearly suggests the implication of ROS in anticandidal activity of EtZnO NPs. This green approach based on egg white-mediated synthesis of ZnO NPs paves the way for developing cost effective, eco-friendly and promising antimicrobial nanomaterial for applications in medicine. (paper)

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Contribution of the ROS-p53 feedback loop in thuja-induced apoptosis of mammary epithelial carcinoma cells.  

Science.gov (United States)

The adverse side-effects associated with chemotherapy during cancer treatment have shifted considerable focus towards therapies that are targeted but devoid of toxic side-effects. In the present study, the antitumorigenic activity of thuja, the bioactive derivative of the medicinal plant Thuja occidentalis, was evaluated, and the molecular mechanisms underlying thuja-induced apoptosis of functional p53-expressing mammary epithelial carcinoma cells were elucidated. Our results showed that thuja successfully induced apoptosis in functional p53-expressing mammary epithelial carcinoma cells. Abrogation of intracellular reactive oxygen species (ROS), prevention of p53-activation, knockdown of p53 or inhibition of its functional activity significantly abridged ROS generation. Notably, under these conditions, thuja-induced breast cancer cell apoptosis was reduced, thereby validating the existence of an ROS-p53 feedback loop. Elucidating this feedback loop revealed bi-phasic ROS generation as a key mediator of thuja-induced apoptosis. the first phase of ROS was instrumental in ensuring activation of p53 via p38MAPK and its nuclear translocation for transactivation of Bax, which induced a second phase of mitochondrial ROS to construct the ROS-p53 feedback loop. Such molecular crosstalk induced mitochondrial changes i) to maintain and amplify the thuja signal in a positive self-regulatory feedback manner; and ii) to promote the mitochondrial death cascade through cytochrome c release and caspase-driven apoptosis. These results open the horizon for developing a targeted therapy by modulating the redox status of functional p53-expressing mammary epithelial carcinoma cells by thuja. PMID:24482097

Saha, Shilpi; Bhattacharjee, Pushpak; Mukherjee, Shravanti; Mazumdar, Minakshi; Chakraborty, Samik; Khurana, Anil; Nayak, Debadatta; Manchanda, Rajkumar; Chakrabarty, Rathin; Das, Tanya; Sa, Gaurisankar

2014-04-01

148

Activation of PPAR? counteracts angiotensin II-induced ROS generation by inhibiting rac1 translocation in vascular smooth muscle cells.  

Science.gov (United States)

Angiotensin II (Ang II)-mediated modification of the redox milieu of vascular smooth muscle cells (VSMCs) has been implicated in several pathophysiological processes, including cell proliferation, migration and differentiation. In this study, we demonstrate that the peroxisome proliferator-activated receptor (PPAR) ? counteracts Ang II-induced production of reactive oxygen species (ROS) in VSMCs. Activation of PPAR? by GW501516, a specific ligand for PPAR?, significantly reduced Ang II-induced ROS generation in VSMCs. This effect was, however, reversed in the presence of small interfering (si)RNA against PPAR?. The marked increase in ROS levels induced by Ang II was also eliminated by the inhibition of phosphatidylinositol 3-kinase (PI3K) but not of protein kinase C, suggesting the involvement of the PI3K/Akt signalling pathway in this process. Accordingly, ablation of Akt with siRNA further enhanced the inhibitory effects of GW501516 in Ang II-induced superoxide production. Ligand-activated PPAR? also blocked Ang II-induced translocation of Rac1 to the cell membrane, inhibiting the activation of NADPH oxidases and consequently ROS generation. These results indicate that ligand-activated PPAR? plays an important role in the cellular response to oxidative stress by decreasing ROS generated by Ang II in vascular cells. PMID:22519881

Lee, Hanna; Ham, Sun Ah; Kim, Min Young; Kim, Jae-Hwan; Paek, Kyung Shin; Kang, Eun Sil; Kim, Hyo Jung; Hwang, Jung Seok; Yoo, Taesik; Park, Chankyu; Kim, Jin-Hoi; Lim, Dae-Seog; Han, Chang Woo; Seo, Han Geuk

2012-07-01

149

ROS signaling, oxidative stress and Nrf2 in pancreatic beta-cell function  

International Nuclear Information System (INIS)

This review focuses on the emerging evidence that reactive oxygen species (ROS) derived from glucose metabolism, such as H2O2, act as metabolic signaling molecules for glucose-stimulated insulin secretion (GSIS) in pancreatic beta-cells. Particular emphasis is placed on the potential inhibitory role of endogenous antioxidants, which rise in response to oxidative stress, in glucose-triggered ROS and GSIS. We propose that cellular adaptive response to oxidative stress challenge, such as nuclear factor E2-related factor 2 (Nrf2)-mediated antioxidant induction, plays paradoxical roles in pancreatic beta-cell function. On the one hand, induction of antioxidant enzymes protects beta-cells from oxidative damage and possible cell death, thus minimizing oxidative damage-related impairment of insulin secretion. On the other hand, the induction of antioxidant enzymes by Nrf2 activation blunts glucose-triggered ROS signaling, thus resulting in reduced GSIS. These two premises are potentially relevant to impairment of beta-cells occurring in the late and early stage of Type 2 diabetes, respectively. In addition, we summarized our recent findings that persistent oxidative stress due to absence of uncoupling protein 2 activates cellular adaptive response which is associated with impaired pancreatic beta-cell function.

150

JNK suppression of chemotherapeutic agents-induced ROS confers chemoresistance on pancreatic cancer stem cells.  

Science.gov (United States)

Chemoresistance associated with cancer stem cells (CSCs), which is now being held responsible for the pervasive therapy resistance of pancreatic cancer, poses a major challenge to the successful management of this devastating malignancy. However, the molecular mechanism underlying the marked chemoresistance of pancreatic CSCs remains largely unknown. Here we show that JNK, which is upregulated in pancreatic CSCs and contributes to their maintenance, is critically involved in the resistance of pancreatic CSCs to 5-fluorouracil (5-FU) and gemcitabine (GEM). We found that JNK inhibition effectively sensitizes otherwise chemoresistant pancreatic CSCs to 5-FU and GEM. Significantly, JNK inhibition promoted 5-FU- and GEM-induced increase in intracellular reactive oxygen species (ROS), and scavenging intracellular ROS by use of N-acetylcysteine impaired JNK inhibition-mediated promotion of the cytotoxicity of 5-FU and GEM. Our findings thus suggest that JNK may contribute to the chemoresistance of pancreatic CSCs through prevention of chemotherapeutic agents-induced increase in intracellular ROS. Our findings also suggest that JNK inhibition combined with 5-FU- and/or GEM-based regimens may be a rational therapeutic approach to effectively eliminate pancreatic CSCs. PMID:25473894

Suzuki, Shuhei; Okada, Masashi; Shibuya, Keita; Seino, Manabu; Sato, Atsushi; Takeda, Hiroyuki; Seino, Shizuka; Yoshioka, Takashi; Kitanaka, Chifumi

2014-11-19

151

Adjudin protects rodent cochlear hair cells against gentamicin ototoxicity via the SIRT3-ROS pathway.  

Science.gov (United States)

Hearing loss resulting from hair cell degeneration is a common disease that affects millions of people worldwide. Strategies to overcome the apparent irreversible hair cell loss in mammals become paramount for hearing protection. Here we reported that, by using a well-established gentamicin-induced hair cell loss model in vitro, adjudin, a multi-functional small molecule drug, protected cochlear hair cells from gentamicin damage. Immunohistochemistry, Western blotting and quantitative RT-PCR analyses revealed that adjudin exerted its otoprotective effects by up-regulating the level of Sirt3, a member of Sirtuin family protein located in mitochondria, which regulates reactive oxygen species (ROS) production in cochlear cells and inhibits the production of ROS and apoptotic cells induced by gentamicin. Sirt3 silencing experiments confirmed that Sirt3-ROS signaling axis mediated hair cell protection against gentamicin by adjudin, at least in part. Furthermore, adjudin's otoprotection effects were also observed in an in vivo gentamicin-injured animal model. Taken together, these findings identify adjudin as a novel otoprotective small molecule via elevating Sirt3 levels and Sirt3 may be of therapeutic value in hair cell protection from ototoxic insults. PMID:25640330

Quan, Yizhou; Xia, Li; Shao, Jiaxiang; Yin, Shankai; Cheng, C Yan; Xia, Weiliang; Gao, Wei-Qiang

2015-01-01

152

ROS-dependence of cyclooxygenase-2 induction in rats subjected to unilateral ureteral obstruction  

DEFF Research Database (Denmark)

Oxidative stress resulting from unilateral ureteral obstruction (UUO) may be aggravated by increased production of reactive oxygen species (ROS). Previous studies demonstrated increased COX-2 expression in renal medullary interstitial cells (RMIC) in response to UUO. We investigated both in vivo and in vitro the role of ROS in COX-2 induction in rats subjected to UUO and RMIC cells exposed to oxidative and mechanical stress. Rats subjected to 3-day UUO were treated with 2 mechanistically distinct antioxidants, the NADPH-oxidase inhibitor diphenyleneiodonium (DPI) and the complex I inhibitor rotenone (ROT), to interfere with ROS production. We found that UUO-mediated induction of COX-2 in inner medulla was attenuated by both antioxidants. In addition, DPI and ROT reduced tubular damage and oxidative stress after UUO. Moreover, mechanical stretch induce COX-2 and oxidative stress in RMIC. Likewise, RMIC cells exposed to H2O2 as an inducer of oxidative stress showed increased COX-2 expression and activity, both of which were reduced by DPI and ROT. Similarly, ROS production, which was increased following exposure of RMIC cells to H2O2, was also reduced by DPI and ROT. Furthermore, oxidative stress-induced phosphorylation of ERK1/2 and p38 was blocked by both antioxidants, and inhibition of ERK1/2 and p38 attenuated COX-2 induction in RMIC cells. Notably, COX-2 inhibitors further exacerbated the oxidative stress level in H2O2-exposed RMIC cells. We conclude that oxidative stress as a consequence of UUO stimulates the COX-2 expression through activation of multiple MAP kinases and that COX-2 induction may exert a cytoprotective function in RMIC cells.

Oestergaard, Martin; Christensen, Michael

2013-01-01

153

Mechanistic Investigation of ROS-Induced DNA Damage by Oestrogenic Compounds in Lymphocytes and Sperm Using the Comet Assay  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Past research has demonstrated that oestrogenic compounds produce strand breaks in the DNA of sperm and lymphocytes via reactive oxygen species (ROS). In the current investigation, sperm and lymphocytes were treated in vitro with oestrogenic compounds (diethylstilboestrol, progesterone, 17?-oestradiol, noradrenaline and triiodotyronine) and several aspects of DNA damage were investigated. Firstly, mediation of DNA damage by lipid peroxidation was investigated in the presence of BHA (a lipid ...

Diana Anderson; Eduardo Cemeli

2011-01-01

154

PERK is required at the ER-mitochondrial contact sites to convey apoptosis after ROS-based ER stress  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Endoplasmic reticulum stress is emerging as an important modulator of different pathologies and as a mechanism contributing to cancer cell death in response to therapeutic agents. In several instances, oxidative stress and the onset of endoplasmic reticulum (ER) stress occur together; yet, the molecular events linking reactive oxygen species (ROS) to ER stress-mediated apoptosis are currently unknown. Here, we show that PERK (RNA-dependent protein kinase (PKR)-like ER kinase), a key ER stress...

Verfaillie, T.; Rubio, N.; Garg, A. D.; Bultynck, G.; Rizzuto, R.; Decuypere, J-p; Piette, J.; Linehan, C.; Gupta, S.; Samali, A.; Agostinis, P.

2012-01-01

155

MaROS: Information Management Service  

Science.gov (United States)

This software is provided by the Mars Relay Operations Service (MaROS) task to a variety of Mars projects for the purpose of coordinating communications sessions between landed spacecraft assets and orbiting spacecraft assets at Mars. The Information Management Service centralizes a set of functions previously distributed across multiple spacecraft operations teams, and as such, greatly improves visibility into the end-to-end strategic coordination process. Most of the process revolves around the scheduling of communications sessions between the spacecraft during periods of time when a landed asset on Mars is geometrically visible by an orbiting spacecraft. These relay sessions are used to transfer data both to and from the landed asset via the orbiting asset on behalf of Earth-based spacecraft operators. This software component is an application process running as a Java virtual machine. The component provides all service interfaces via a Representational State Transfer (REST) protocol over https to external clients. There are two general interaction modes with the service: upload and download of data. For data upload, the service must execute logic specific to the upload data type and trigger any applicable calculations including pass delivery latencies and overflight conflicts. For data download, the software must retrieve and correlate requested information and deliver to the requesting client. The provision of this service enables several key advancements over legacy processes and systems. For one, this service represents the first time that end-to-end relay information is correlated into a single shared repository. The software also provides the first multimission latency calculator; previous latency calculations had been performed on a mission-by-mission basis.

Allard, Daniel A.; Gladden, Roy E.; Wright, Jesse J.; Hy, Franklin H.; Rabideau, Gregg R.; Wallick, Michael N.

2011-01-01

156

Philip Glass, Scott Walker ja Sigur Ros! / Immo Mihkelson  

Index Scriptorium Estoniae

Pimedate Ööde 11. filmifestivali muusikafilme - Austraalia "Glass: Philipi portree 12 osas" (rež. Scott Hicks), Islandi "Sigur Ros kodus" (rež. Dean DeBois), Suurbritannia "Scott Walker: 30 Century Man" (rež. Stephen Kijak)

Mihkelson, Immo, 1959-

2007-01-01

157

Molecular pathways: ROS1 fusion proteins in cancer.  

Science.gov (United States)

Genetic alterations that lead to constitutive activation of kinases are frequently observed in cancer. In many cases, the growth and survival of tumor cells rely upon an activated kinase such that inhibition of its activity is an effective anticancer therapy. ROS1 is a receptor tyrosine kinase that has recently been shown to undergo genetic rearrangements in a variety of human cancers, including glioblastoma, non-small cell lung cancer (NSCLC), cholangiocarcinoma, ovarian cancer, gastric adenocarcinoma, colorectal cancer, inflammatory myofibroblastic tumor, angiosarcoma, and epithelioid hemangioendothelioma. These rearrangements create fusion proteins in which the kinase domain of ROS1 becomes constitutively active and drives cellular proliferation. Targeting ROS1 fusion proteins with the small-molecule inhibitor crizotinib is showing promise as an effective therapy in patients with NSCLC whose tumors are positive for these genetic abnormalities. This review discusses the recent preclinical and clinical findings on ROS1 gene fusions in cancer. PMID:23719267

Davies, Kurtis D; Doebele, Robert C

2013-08-01

158

Differences Between ROS And Researchfish - Research Councils UK  

Researchers control who can see/edit their data. ... A template spreadsheet could \\be used to upload details of multiple outcomes across multiple awards. ... Please \\contact researchoutcomes@rcuk.ac.uk for assistance in accessing ROS ...

159

Menadione triggers cell death through ROS-dependent mechanisms involving PARP activation without requiring apoptosis.  

Science.gov (United States)

Low levels of reactive oxygen species (ROS) can function as redox-active signaling messengers, whereas high levels of ROS induce cellular damage. Menadione generates ROS through redox cycling, and high concentrations trigger cell death. Previous work suggests that menadione triggers cytochrome c release from mitochondria, whereas other studies implicate the activation of the mitochondrial permeability transition pore as the mediator of cell death. We investigated menadione-induced cell death in genetically modified cells lacking specific death-associated proteins. In cardiomyocytes, oxidant stress was assessed using the redox sensor RoGFP, expressed in the cytosol or the mitochondrial matrix. Menadione elicited rapid oxidation in both compartments, whereas it decreased mitochondrial potential and triggered cytochrome c redistribution to the cytosol. Cell death was attenuated by N-acetylcysteine and exogenous glutathione or by overexpression of cytosolic or mitochondria-targeted catalase. By contrast, no protection was observed in cells overexpressing Cu,Zn-SOD or Mn-SOD. Overexpression of antiapoptotic Bcl-X(L) protected against staurosporine-induced cell death, but it failed to confer protection against menadione. Genetic deletion of Bax and Bak, cytochrome c, cyclophilin D, or caspase-9 conferred no protection against menadione-induced cell death. However, cells lacking PARP-1 showed a significant decrease in menadione-induced cell death. Thus, menadione induces cell death through the generation of oxidant stress in multiple subcellular compartments, yet cytochrome c, Bax/Bak, caspase-9, and cyclophilin D are dispensable for cell death in this model. These studies suggest that multiple redundant cell death pathways are activated by menadione, but that PARP plays an essential role in mediating each of them. PMID:20937380

Loor, Gabriel; Kondapalli, Jyothisri; Schriewer, Jacqueline M; Chandel, Navdeep S; Vanden Hoek, Terry L; Schumacker, Paul T

2010-12-15

160

Aged Garlic Extract Reduces ROS Production and Cell Death Induced by 6-Hydroxydopamine through Activation of the Nrf2-ARE Pathway in SH-SY5Y Cells  

Directory of Open Access Journals (Sweden)

Full Text Available Many degenerative or pathological processes, such as aging, cancer and coronary heart disease, are related to reactive oxygen species (ROS and radical-mediated reactions. We examined the effectiveness of aged garlic extract (AGE, a garlic preparation rich in water-soluble cysteinyl moieties, for protection of cells from ROS produced by 6-hydroxy-dopamine (6-OHDA using human neuroblastoma SH-SY5Y cells. Concomitant treatment of cells with AGE (2 and 4 mg/ml showed the dose-dependent protective effect on the cell death induced by 6-OHDA. In addition, the AGE treatment significantly suppressed the increase of ROS generation by 6-OHDA. Furthermore, the protective effect of AGE was accompanied by activation of the nuclear factor erythroid 2-related factor 2 (Nrf2-antioxidant response element (ARE pathway and the increase of mRNAs of heme oxygenase-1 and NAD(PH quinone oxidoreductase 1. These two enzymes are important in the cellular antioxidant system. These results indicated that AGE protected cells from ROS damage by not only capturing ROS directly but also activating the cellular antioxidant system by stimulating antioxidant gene expression via the Nrf2-ARE pathway. The present study suggested that AGE may be useful for prevention and treatment of cell damage caused by ROS.

Tomoko Fukuuchi

2013-01-01

 
 
 
 
161

MITOCHONDRIAL REACTIVE OXYGEN SPECIES (ROS AS SIGNALLING MOLECULES OF INTRACELLULAR PATHWAYS TRIGGERED BY THE CARDIAC RENIN-ANGIOTENSIN II-ALDOSTERONE SYSTEM (RAAS.  

Directory of Open Access Journals (Sweden)

Full Text Available Mitochondria represent major sources of basal reactive oxygen species (ROS production of the cardiomyocyte. The role of ROS as signalling molecules that mediate different intracellular pathways has gained increasing interest among physiologists in the last years. In our lab, we have been studying the participation of mitochondrial ROS in the intracellular pathways triggered by the renin-angiotensin II-aldosterone system (RAAS in the myocardium during the past few years. We have demonstrated that acute activation of cardiac RAAS induces mitochondrial ATP-dependent potassium channel (mitoKATP opening with the consequent enhanced production of mitochondrial ROS. These oxidant molecules, in turn, activate membrane transporters, as sodium/hydrogen exchanger (NHE-1 and sodium/bicarbonate cotransporter (NBC via the stimulation of the ROS-sensitive MAPK cascade. The stimulation of such effectors leads to an increase in cardiac contractility. In addition, it is feasible to suggest that a sustained enhanced production of mitochondrial ROS induced by chronic cardiac RAAS, and hence, chronic NHE-1 and NBC stimulation, would also result in the development of cardiac hypertrophy.

ErnestoAlejandroAiello

2013-05-01

162

Reactive oxygen species (ROS) induced cytokine production and cytotoxicity of PAMAM dendrimers in J774A.1 cells  

International Nuclear Information System (INIS)

The immunotoxicity of three generations of polyamidoamine (PAMAM) dendrimers (G-4, G-5 and G-6) was evaluated in mouse macrophage cells in vitro. Using the Alamar blue and MTT assays, a generation dependent cytotoxicity of the PAMAM dendrimers was found whereby G-6 > G-5 > G-4. The toxic response of the PAMAM dendrimers correlated well with the number of surface primary amino groups, with increasing number resulting in an increase in toxic response. An assessment of intracellular ROS generation by the PAMAM dendrimers was performed by measuring the increased fluorescence as a result of intracellular oxidation of Carboxy H2DCFDA to DCF both quantitatively using plate reader and qualitatively by confocal laser scanning microscopy. The inflammatory mediators macrophage inflammatory protein-2 (MIP-2), tumour necrosis factor-? (TNF-?) and interleukin-6, (IL-6) were measured by the enzyme linked immunosorbant assay (ELISA) following exposure of mouse macrophage cells to PAMAM dendrimers. A generation dependent ROS and cytokine production was found, which correlated well with the cytotoxicological response and therefore number of surface amino groups. A clear time sequence of increased ROS generation (maximum at ? 4 h), TNF-? and IL-6 secretion (maximum at ? 24 h), MIP-2 levels and cell death (? 72 h) was observed. The intracellular ROS generation and cytokine production induced cytotoxicity point towards the mechanistic pathway of cell death upon exposurathway of cell death upon exposure to PAMAM dendrimers.

163

Genistein Inhibits Osteoclastic Differentiation of RAW 264.7 Cells via Regulation of ROS Production and Scavenging  

Directory of Open Access Journals (Sweden)

Full Text Available Genistein, a phytoestrogen, has been demonstrated to have a bone-sparing and antiresorptive effect. Genistein can inhibit the osteoclast formation of receptor activator of nuclear factor-?B ligand (RANKL-induced RAW 264.7 cells by preventing the translocation of nuclear factor-?B (NF-?B, a redox-sensitive factor, to the nucleus. Therefore, the suppressive effect of genistein on the reactive oxygen species (ROS level during osteoclast differentiation and the mechanism associated with the control of ROS levels by genistein were investigated. The cellular antioxidant capacity and inhibitory effect of genistein were confirmed. The translation and activation of nicotinamide adenine dinucleotide phosphate (NADPH oxidase 1 (Nox1, as well as the disruption of the mitochondrial electron transport chain system were obviously suppressed by genistein in a dose-dependent manner. The induction of phase II antioxidant enzymes, such as superoxide dismutase 1 (SOD1 and heme oxygenase-1 (HO-1, was enhanced by genistein. In addition, the translational induction of nuclear factor erythroid 2-related factor 2 (Nrf2 was notably increased by genistein. These results provide that the inhibitory effects of genistein on RANKL-stimulated osteoclast differentiation is likely to be attributed to the control of ROS generation through suppressing the translation and activation of Nox1 and the disruption of the mitochondrial electron transport chain system, as well as ROS scavenging through the Nrf2-mediated induction of phase II antioxidant enzymes, such as SOD1 and HO-1.

Sang-Hyun Lee

2014-06-01

164

Hesperetin induces apoptosis in breast carcinoma by triggering accumulation of ROS and activation of ASK1/JNK pathway.  

Science.gov (United States)

Hesperetin, a flavanone glycoside predominantly found in citrus fruits, exhibits a wide array of biological properties. In the present study hesperetin exhibited a significant cytotoxic effect in human breast carcinoma MCF-7 cells in a concentration- and time-dependent manner without affecting normal (HMEC) as well as immortalized normal mammary epithelial cells (MCF-10A). The cytotoxic effect of hesperetin was due to the induction of apoptosis as evident from the phosphatidyl-serine externalization, DNA fragmentation, caspase-7 activation and PARP cleavage. Apoptosis was associated with caspase-9 activation, mitochondrial membrane potential loss, release of cytochrome c and increase in Bax:Bcl-2 ratio. Pre-treatment with caspase-9 specific inhibitor (Z-LEHD-fmk) markedly attenuated apoptosis suggesting an involvement of intrinsic mitochondrial apoptotic cascade. Further, DCFDA flow-cytometric analysis revealed triggering of ROS in a time-dependent manner. Pre-treatment with ROS scavenger N-acetylcysteine (NAC) and glutathione markedly abrogated hesperetin-mediated apoptosis whereas carbonyl cyanide m-chlorophenylhydrazone (CCCP) pretreatment along with DHR123-based flow-cytometry indicated the generation of cytosolic ROS. Profiling of MAPKs revealed activation of JNK upon hesperetin treatment which was abrogated upon NAC pretreatment. Additionally, inhibition of JNK by SP600125 significantly reversed hesperetinmediated apoptosis. The activation of JNK was associated with the activation of ASK1. Silencing of ASK1 resulted in significant attenuation of JNK activation as well as reversed the hesperetin-mediated apoptosis suggesting that hesperetin-mediated apoptosis of MCF-7 cells involves accumulation of ROS and activation of ASK1/JNK pathway. In addition, hesperetin also induced apoptosis in triple negative breast cancer MDA-MB-231 cells via intrinsic pathway via activation of caspase -9 and -3 and increase in Bax:Bcl-2 ratio. J. Cell. Physiol. © 2014 Wiley Periodicals, Inc. PMID:25204891

Palit, Shreyasi; Kar, Susanta; Sharma, Gunjan; Das, Pijush K

2014-09-10

165

P8 deficiency increases cellular ROS and induces HO-1.  

Science.gov (United States)

The gene p8 encodes for a small cytoprotective protein with no apparent enzymatic activity being proposed to act as co-transcription factor whose expression is increased during inflammation. Recent data from astrocytes demonstrates that p8 suppression leads to induction of heme oxygenase 1 (HO-1). Here, we assessed the cross-talk between p8 and HO-1 in mouse embryonic fibroblasts (MEF) observing an increased expression of HO-1 in p8-deficient (p8(-/-)) MEFs in non-treated and treated conditions. This effect was independent of the cell cycle. Our findings revealed that generation of reactive oxygen species (ROS) was higher in p8(-/-) MEFs. Mitochondria and NADPH oxidases were not the origin of ROS. This observation was not restricted to MEF as suppression of p8 gene transcription in MiaPaCa-2 cells also led to increased intracellular ROS. Additionally, p8 deficiency did not affect the Rac1 dependant NADPH oxidase complex. Our data shows that p8 deficiency increases ROS and subsequently the expression of anti-oxidative enzymes, such as HO-1, suggesting an involvement in the anti-oxidative defense. Moreover, we suggest that the severity of AP observed in p8(-/-) mice is induced by an impaired anti oxidative capacity of the pancreas, which is caused by increased generation of ROS. PMID:25475530

Weis, Sebastian; Bielow, Tobias; Sommerer, Ines; Iovanna, Juan; Malicet, Cédric; Mössner, Joachim; Hoffmeister, Albrecht

2015-01-01

166

Interfering with ROS Metabolism in Cancer Cells: The Potential Role of Quercetin  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A main feature of cancer cells, when compared to normal ones, is a persistent pro-oxidative state that leads to an intrinsic oxidative stress. Cancer cells have higher levels of reactive oxygen species (ROS) than normal cells, and ROS are, in turn, responsible for the maintenance of the cancer phenotype. Persistent ROS stress may induce adaptive stress responses, enabling cancer cells to survive with high levels of ROS and maintain cellular viability. However, excessive ROS levels render canc...

Lara Gibellini; Marcello Pinti; Milena Nasi; Sara De Biasi; Erika Roat; Linda Bertoncelli; Andrea Cossarizza

2010-01-01

167

Psoralidin induces autophagy through ROS generation which inhibits the proliferation of human lung cancer A549 cells  

Science.gov (United States)

Psoralidin (PSO), a natural furanocoumarin, is isolated from Psoralea corylifolia L. possessing anti-cancer properties. However, the mechanisms of its effects remain unclear. Herein, we investigated its anti-proliferative effect and potential approaches of action on human lung cancer A549 cells. Cell proliferation and death were measured by MTT and LDH assay respectively. Apoptosis was detected with Hoechst 33342 staining by fluorescence microscopy, Annexin V-FITC by flow cytometry and Western blot analysis for apoptosis-related proteins. The autophagy was evaluated using MDC staining, immunofluorescence assay and Western blot analyses for LC3-I and LC3-II. In addition, the reactive oxygen species (ROS) generation was measured by DCFH2-DA with flow cytometry. PSO dramatically decreased the cell viabilities in dose- and time-dependent manner. However, no significant change was observed between the control group and the PSO-treated groups in Hoechst 33342 and Annexin V-FITC staining. The expression of apoptosis-related proteins was not altered significantly either. While the MDC-fluorescence intensity and the expression ratio of LC3-II/LC3-I was remarkably increased after PSO treatment. Autophagy inhibitor 3-MA blocked the production of LC3-II and reduced the cytotoxicity in response to PSO. Furthermore, PSO increased intracellular ROS level which was correlated to the elevation of LC3-II. ROS scavenger N-acetyl cysteine pretreatment not only decreased the ROS level, reduced the expression of LC3-II but also reversed PSO induced cytotoxicity. PSO inhibited the proliferation of A549 cells through autophagy but not apoptosis, which was mediated by inducing ROS production. PMID:25250213

Hao, Wenhui; Zhang, Xuenong; Zhao, Wenwen

2014-01-01

168

Inhibition of Telomerase Activity by Oleanane Triterpenoid CDDO-Me in Pancreatic Cancer Cells is ROS-Dependent  

Directory of Open Access Journals (Sweden)

Full Text Available Methyl-2-cyano-3,12-dioxooleana-1,9(11-dien-28-oate (CDDO-Me is a synthetic derivative of oleanolic acid, a triterpene, with apoptosis-inducing activity in a wide range of cancer cells. Induction of apoptosis by CDDO-Me is associated with the generation of reactive oxygen species (ROS and inhibition of telomerase activity. In the present study, we investigated the role of ROS in inhibition of telomerase by CDDO-me. Treatment of MiaPaCa-2 and Panc-1 pancreatic cancer cell lines with CDDO-Me induced the production of hydrogen peroxide and superoxide anions and inhibited the telomerase activity. Pretreatment of cells with N-acetylcycsteine, a general purpose antioxidant or overexpression of glutathione peroxidase (GPx or superoxide dismutase-1 (SOD-1 blocked the telomerase inhibitory activity of CDDO-Me. Furthermore, blocking ROS generation also prevented the inhibition of hTERT gene expression, hTERT protein production and expression of a number of hTERT–regulatory proteins by CDDO-Me (e.g., c-Myc, Sp1, NF-?B and p-Akt. Data also showed that Akt plays an important role in the activation of telomerase activity. Together, these data suggest that inhibition of telomerase activity by CDDO-Me is mediated through a ROS-dependent mechanism; however, more work is needed to fully understand the role of ROS in down-regulation of hTERT gene and hTERT-regulatory proteins by CDDO-Me.

Subhash C. Gautam

2013-03-01

169

Intracellular generation of ROS by 3,5-dimethylaminophenol: persistence, cellular response, and impact of molecular toxicity.  

Science.gov (United States)

Epidemiological studies have demonstrated extensive human exposure to the monocyclic aromatic amines, particularly to 3,5-dimethylaniline, and found an association between exposure to these compounds and risk for bladder cancer. Little is known about molecular mechanisms that might lead to the observed risk. We previously suggested that the hydroxylated 3,5-dimethylaniline metabolite, 3,5-dimethylaminophenol (3,5-DMAP), played a central role in effecting genetic change through the generation of reactive oxygen species (ROS) in a redox cycle with 3,5-dimethylquinoneimine. Experiments here characterize ROS generation by 3,5-DMAP exposure in nucleotide repair-proficient and -deficient Chinese hamster ovary cells as a function of time. Besides, various cellular responses discussed herein indicate that ROS production is the principal cause of cytotoxicity. Fluorescence microscopy of cells exposed to 3,5-DMAP confirmed that ROS production occurs in the nuclear compartment, as suggested by a previous study demonstrating covalent linkage between 3,5-DMAP and histones. 3,5-DMAP was also compared with 3,5-dimethylhydroquinone to determine whether substitution of one of the phenolic hydroxyl groups by an amino group had a significant effect on some of the investigated parameters. The comparatively much longer duration of observable ROS produced by 3,5-DMAP (7 vs. 1 day) provides further evidence that 3,5-DMAP becomes embedded in the cellular matrix in a form capable of continued redox cycling. 3,5-DMAP also induced dose-dependent increase of H2O2 and ·OH, which were determined as the major free radicals contributing to the cytotoxicity and apoptosis mediated via caspase-3 activation. Overall, this study provides insight into the progression of alkylaniline-induced toxicity. PMID:24973092

Chao, Ming-Wei; Erkekoglu, Pinar; Tseng, Chia-Yi; Ye, Wenjie; Trudel, Laura J; Skipper, Paul L; Tannenbaum, Steven R; Wogan, Gerald N

2014-09-01

170

Roles for mannitol and mannitol dehydrogenase in active oxygen-mediated plant defense  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reactive oxygen species (ROS) are both signal molecules and direct participants in plant defense against pathogens. Many fungi synthesize mannitol, a potent quencher of ROS, and there is growing evidence that at least some phytopathogenic fungi use mannitol to suppress ROS-mediated plant defenses. Here we show induction of mannitol production and secretion in the phytopathogenic fungus Alternaria alternata in the presence of host-plant extracts. Conversely, we show that the catabolic enzyme m...

Jennings, Dianne B.; Ehrenshaft, Marilyn; Pharr, D. Mason; Williamson, John D.

1998-01-01

171

Effect of ionizing radiation on the differentiation of ROS 17/2.8 osteoblasts through free radicals  

International Nuclear Information System (INIS)

Although the acceleration of bone regeneration by radiation has been reported, the mechanisms of action of radiation on bone are unclear. The present results indicate that ionizing radiation-stimulated differentiation could result from the generation of reactive oxygen species during radiation exposure. The free radical release is considered as the most important mechanism of bone effect by radiation treatment. In addition, we report that radiation induced transient activation of c-Jun N-terminal kinase/ stress-activated protein kinase (JNK/SAPK) activation and the transcription factor, AP-1. The JNK and AP-1 activation is mediated with radiation-released free radicals in ROS 17/2.8 osteoblasts. These results indicate that ionizing radiation at a single dose of up to 5 Gray stimulates differentiation of ROS 17/2.8 osteoblasts via free radial release which may affect JNK/SAPK and AP-1 activities. (author)

172

Cadmium induces carcinogenesis in BEAS-2B cells through ROS-dependent activation of PI3K/AKT/GSK-3?/?-catenin signaling  

Energy Technology Data Exchange (ETDEWEB)

Cadmium has been widely used in industry and is known to be carcinogenic to humans. Although it is widely accepted that chronic exposure to cadmium increases the incidence of cancer, the mechanisms underlying cadmium-induced carcinogenesis are unclear. The main aim of this study was to investigate the role of reactive oxygen species (ROS) in cadmium-induced carcinogenesis and the signal transduction pathways involved. Chronic exposure of human bronchial epithelial BEAS-2B cells to cadmium induced cell transformation, as evidenced by anchorage-independent growth in soft agar and clonogenic assays. Chronic cadmium treatment also increased the potential of these cells to invade and migrate. Injection of cadmium-stimulated cells into nude mice resulted in the formation of tumors. In contrast, the cadmium-mediated increases in colony formation, cell invasion and migration were prevented by transfection with catalase, superoxide dismutase-1 (SOD1), or SOD2. In particular, chronic cadmium exposure led to activation of signaling cascades involving PI3K, AKT, GSK-3?, and ?-catenin and transfection with each of the above antioxidant enzymes markedly inhibited cadmium-mediated activation of these signaling proteins. Inhibitors specific for AKT or ?-catenin almost completely suppressed the cadmium-mediated increase in total and active ?-catenin proteins and colony formation. Moreover, there was a marked induction of AKT, GSK-3?, ?-catenin, and carcinogenic markers in tumor tissues formed in mice after injection with cadmium-stimulated cells. Collectively, our findings suggest a direct involvement of ROS in cadmium-induced carcinogenesis and implicate a role of AKT/GSK-3?/?-catenin signaling in this process. -- Highlights: ? Chronic exposure to cadmium induces carcinogenic properties in BEAS-2B cells. ? ROS involved in cadmium-induced tumorigenicity of BEAS-2B cells. ? Cadmium activates ROS-dependent AKT/GSK-3?/?-catenin-mediated signaling. ? ROS-dependent signaling as potential therapeutic targets in cadmium carcinogenesis.

Son, Young-Ok; Wang, Lei; Poyil, Pratheeshkumar; Budhraja, Amit; Hitron, J. Andrew; Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States); School of Dentistry and Institute of Oral Biosciences (BK21 program), Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY (United States)

2012-10-15

173

NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-?-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells  

Energy Technology Data Exchange (ETDEWEB)

TNF-? plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-? in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-?-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-? induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-?-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-L-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-?B (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47{sup phox}, p42, p38, JNK1, p65, or PYK2. Moreover, TNF-? markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-?-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-?B (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-?-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-?-stimulated MAPKs and NF-?B activation. Thus, in H9c2 cells, we are the first to show that TNF-?-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-?B cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-?-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-? on H9c2 cells may provide potential therapeutic targets of chronic heart failure. - Highlights: • TNF-? induces MMP-9 secretion and expression via a TNFR1-dependent pathway. • TNF-? induces ROS/PYK2-dependent MMP-9 expression in H9c2 cells. • TNF-? induces MMP-9 expression via a NADPH oxidase/ROS-dependent NF-?B signaling. • TNF-? activates MAPK phosphorylation through NADPH oxidase/ROS generation.

Yang, Chuen-Mao, E-mail: chuenmao@mail.cgu.edu.tw [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Heart Failure Center, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan (China); Lee, I-Ta [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Department of Anesthetics, Chang Gung Memorial Hospital at Linkou and College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Hsu, Ru-Chun; Chi, Pei-Ling; Hsiao, Li-Der [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China)

2013-10-15

174

NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-?-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells  

International Nuclear Information System (INIS)

TNF-? plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-? in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-?-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-? induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-?-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-L-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-?B (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47phox, p42, p38, JNK1, p65, or PYK2. Moreover, TNF-? markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-?-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-?B (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-?-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-?-stimulated MAPKs and NF-?B activation. Thus, in H9c2 cells, we are the first to show that TNF-?-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-?B cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-?-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-? on H9c2 cells may provide potential therapeutic targets of chronic heart failure. - Highlights: • TNF-? induces MMP-9 secretion and expression via a TNFR1-dependent pathway. • TNF-? induces ROS/PYK2-dependent MMP-9 expression in H9c2 cells. • TNF-? induces MMP-9 expression via a NADPH oxidase/ROS-dependent NF-?B signaling. • TNF-? activates MAPK phosphorylation through NADPH oxidase/ROS generation

175

Kuula : Sigur Ros rokiklubis. Kammemuusikat Tallinnas. Loomade reekviem  

Index Scriptorium Estoniae

23. aug. esineb Tallinna rokiklubis Rock Café islandi bänd Sigur Ros. Pille Lille muusikute toetusfondi korraldatavast Tallinna Kammermuusika festivalist 17.-23. aug. Tallinna Rootsi Mihkli kirikus, Raekojas ja Jaani kirkus (vt. www.plmf.ee). Kontserdist Nargen Festivali raames 30. ja 31. aug. Tallinna loomaaias

2008-01-01

176

Religious Occupations and Stress Questionnaire (ROS): Instrument Development.  

Science.gov (United States)

Describes the development of the Religious Occupations and Stress Questionnaire (ROS), which attempts to fill the need for an appropriate measure of the stress experienced by individuals in religious occupations. Results of reliability and validity studies indicate high internal consistency, test-retest reliability, and construct validity.…

Birk, Janice M.; Rayburn, Carole A.; Richmond, Lee J.

2001-01-01

177

Interfering with ROS Metabolism in Cancer Cells: The Potential Role of Quercetin.  

Science.gov (United States)

A main feature of cancer cells, when compared to normal ones, is a persistent pro-oxidative state that leads to an intrinsic oxidative stress. Cancer cells have higher levels of reactive oxygen species (ROS) than normal cells, and ROS are, in turn, responsible for the maintenance of the cancer phenotype. Persistent ROS stress may induce adaptive stress responses, enabling cancer cells to survive with high levels of ROS and maintain cellular viability. However, excessive ROS levels render cancer cells highly susceptible to quercetin, one of the main dietary flavonoids. Quercetin depletes intracellular glutathione and increases intracellular ROS to a level that can cause cell death. PMID:24281116

Gibellini, Lara; Pinti, Marcello; Nasi, Milena; De Biasi, Sara; Roat, Erika; Bertoncelli, Linda; Cossarizza, Andrea

2010-01-01

178

Interfering with ROS Metabolism in Cancer Cells: The Potential Role of Quercetin  

Directory of Open Access Journals (Sweden)

Full Text Available A main feature of cancer cells, when compared to normal ones, is a persistent pro-oxidative state that leads to an intrinsic oxidative stress. Cancer cells have higher levels of reactive oxygen species (ROS than normal cells, and ROS are, in turn, responsible for the maintenance of the cancer phenotype. Persistent ROS stress may induce adaptive stress responses, enabling cancer cells to survive with high levels of ROS and maintain cellular viability. However, excessive ROS levels render cancer cells highly susceptible to quercetin, one of the main dietary flavonoids. Quercetin depletes intracellular glutathione and increases intracellular ROS to a level that can cause cell death.

Lara Gibellini

2010-06-01

179

The interplay between autophagy and ROS in tumorigenesis  

Directory of Open Access Journals (Sweden)

Full Text Available Reactive oxygen species (ROS at physiological levels are important cell signaling molecules. However, aberrantly high ROS are intimately associated with disease and commonly observed in cancer. Mitochondria are primary sources of intracellular ROS, and their maintenance is essential to cellular health. Autophagy, an evolutionarily conserved process whereby cytoplasmic components are delivered to lysosomes for degradation, is responsible for mitochondrial turnover and removal of damaged mitochondria. Impaired autophagy is implicated in many pathological conditions, including neurological disorders, inflammatory bowel disease, diabetes, aging and cancer. The first reports connecting autophagy to cancer showed that allelic loss of the essential autophagy gene BECLIN1 (BECN1 is prevalent in human breast, ovarian and prostate cancers and that Becn1+/- mice develop mammary gland hyperplasias, lymphomas, and lung and liver tumors. Subsequent studies demonstrated that Atg5-/- and Atg7-/- livers give rise to adenomas, Atg4-/- mice are susceptible to chemical carcinogenesis, and Bif1-/- mice are prone to spontaneous tumors, indicating that autophagy defects promote tumorigenesis. Due to defective mitophagy, autophagy-deficient cells accumulate damaged mitochondria and deregulated ROS levels, which likely contribute to their tumor-initiating capacity. However, the role of autophagy in tumorigenesis is complex, as more recent work also revealed tumor dependence on autophagy: autophagy-competent mutant-Ras-expressing cells form tumors more efficiently than their autophagy-deficient counterparts; similarly, FIP200 deficiency suppresses PyMT-driven mammary tumorigenesis. These latter findings are attributed to the fact that tumors driven by powerful oncogenes have high metabolic demands catered to by autophagy. In this review, we discuss the relationship between ROS and autophagy and summarize our current knowledge on their functional interactions in tumorigenesis.

VassilikiKarantza

2012-11-01

180

Un col.loqui poc conegut de Carles Ros [A hardly known col.loqui by Carles Ros  

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Full Text Available This paper deals with the philological edition of a literary text by the 18th c. Valencian grammarian and poet Carles Ros i Hebrera, “Paper graciós, discursiu, enfàtic, alusiu i sentenciós per a desfresar-se de llaurador a les carnistoltes”. This text is part of a group of humorous “col•loquis” which Ros wrote on the occasion of the carnival. This edition is important since this dialogue has not been recorded in any of the compilations and studies of Ros’ works so far, despite belonging to one of the most popular groups of his works. Moreover, it has lately been listed within the lost or impossible to find works by the famous Valencian author. Finally this edition of the text, which entails several variations when compared to the other editions, is different from those mentioned by the bibliographers. The paper also encloses a study on the importance of the literary and linguistic works by Carles Ros, as well as a philological and literary analysis of the text we are editing.

Martí Mestre, Joaquim

2006-01-01

 
 
 
 
181

Triiodothyronine (T3) does not induce Rankl expression in rat Ros 17/2.8 cells Triiodotironina (T3) não induz a expressão de Rankl em células de rato ROS 17/2.8  

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Osteoclastogenesis may be regulated via activation of the RANK/RANKL (receptor activator of nuclear factor-kappa B/ receptor activator of nuclear factor-kappa B ligand) system, which is mediated by osteoblasts. However, the bone loss mechanism induced by T3 (triiodothyronine) is still controversial. In this study, osteoblastic lineage rat cells (ROS 17/2.8) were treated with T3 (10-8 M, 10-9 M, and 10-10 M), and RANKL mRNA (messenger RNA) expression was measured by semiquantitative RT-PCR. Ou...

Saraiva, Patri?cia P.; Teixeira, Silvania S.; Célia Regina Nogueira; Carlos Roberto Padovani

2008-01-01

182

No evident dose-response relationship between cellular ROS level and its cytotoxicity--a paradoxical issue in ROS-based cancer therapy.  

Science.gov (United States)

Targeting cancer via ROS-based mechanism has been proposed as a radical therapeutic approach. Cancer cells exhibit higher endogenous oxidative stress than normal cells and pharmacological ROS insults via either enhancing ROS production or inhibiting ROS-scavenging activity can selectively kill cancer cells. In this study, we randomly chose 4 cancer cell lines and primary colon or rectal cancer cells from 4 patients to test the hypothesis and obtained following paradoxical results: while piperlongumin (PL) and ?-phenylethyl isothiocyanate (PEITC), 2 well-defined ROS-based anticancer agents, induced an increase of cellular ROS and killed effectively the tested cells, lactic acidosis (LA), a common tumor environmental factor that plays multifaceted roles in promoting cancer progression, induced a much higher ROS level in the tested cancer cells than PL and PEITC, but spared them; L-buthionine sulfoximine (L-BSO, 20??M) depleted cellular GSH more effectively and increased higher ROS level than PL or PEITC but permitted progressive growth of the tested cancer cells. No evident dose-response relationship between cellular ROS level and cytotoxicity was observed. If ROS is the effecter, it should obey the fundamental therapeutic principle - the dose-response relationship. This is a major concern. PMID:24848642

Zhu, Chunpeng; Hu, Wei; Wu, Hao; Hu, Xun

2014-01-01

183

No evident dose-response relationship between cellular ROS level and its cytotoxicity – a paradoxical issue in ROS-based cancer therapy  

Science.gov (United States)

Targeting cancer via ROS-based mechanism has been proposed as a radical therapeutic approach. Cancer cells exhibit higher endogenous oxidative stress than normal cells and pharmacological ROS insults via either enhancing ROS production or inhibiting ROS-scavenging activity can selectively kill cancer cells. In this study, we randomly chose 4 cancer cell lines and primary colon or rectal cancer cells from 4 patients to test the hypothesis and obtained following paradoxical results: while piperlongumin (PL) and ?-phenylethyl isothiocyanate (PEITC), 2 well-defined ROS-based anticancer agents, induced an increase of cellular ROS and killed effectively the tested cells, lactic acidosis (LA), a common tumor environmental factor that plays multifaceted roles in promoting cancer progression, induced a much higher ROS level in the tested cancer cells than PL and PEITC, but spared them; L-buthionine sulfoximine (L-BSO, 20??M) depleted cellular GSH more effectively and increased higher ROS level than PL or PEITC but permitted progressive growth of the tested cancer cells. No evident dose-response relationship between cellular ROS level and cytotoxicity was observed. If ROS is the effecter, it should obey the fundamental therapeutic principle – the dose-response relationship. This is a major concern. PMID:24848642

Zhu, Chunpeng; Hu, Wei; Wu, Hao; Hu, Xun

2014-01-01

184

Osthole attenuates doxorubicin-induced apoptosis in PC12 cells through inhibition of mitochondrial dysfunction and ROS production.  

Science.gov (United States)

Doxorubicin (DOX) is a potent, broad-spectrum chemotherapeutic drug used for treatment of several types of cancers. Despite its effectiveness, it has a wide range of toxic side effects, many of which most likely result from its inherent prooxidant activity. It has been reported that DOX has toxic effects on normal tissues, including brain tissue. In the current study, we investigated the protective effect of osthole isolated from Prangos ferulacea (L.) Lindl. on oxidative stress and apoptosis induced by DOX in PC12 as a neuronal model cell line. PC12 cells were pretreated with osthole 2?h after treatment with different concentrations of DOX. 24?h later, the cell viability, mitochondrial membrane potential (MMP), the activity of caspase-3, the expression ratio of Bax/Bcl-2, and the generation of intracellular ROS were detected. We found that pretreatment with osthole on PC12 cells significantly reduced the loss of cell viability, the activity of caspase-3, the increase in Bax/Bcl-2 ratio, and the generation of intracellular ROS induced by DOX. Moreover, pretreatment with osthole led to an increase in MMP in PC12 cells. In conclusion, our results indicated that pretreatment with nontoxic concentrations of osthole protected PC12 cells from DOX-mediated apoptosis by inhibition of ROS production. PMID:25013759

Shokoohinia, Yalda; Hosseinzadeh, Leila; Moieni-Arya, Maryam; Mostafaie, Ali; Mohammadi-Motlagh, Hamid-Reza

2014-01-01

185

Clinical Significance of ROS1 Rearrangements in Non-small Cell Lung Cancer  

Directory of Open Access Journals (Sweden)

Full Text Available Chromosomal rearrangements involving the ROS1 receptor tyrosine kinase gene have recently been described in multiple malignancies, including non-small cell lung cancer (NSCLC. ROS1 rearrangement defines a new molecular subset of NSCLC with the prevalence of ROS1 rearrangements around 1%-2%. ROS1-positive NSCLCs arise in young never-smokers with adenocarcinoma that are similar to those observed in patients with ALK-rearranged NSCLC. Crizotinib demonstrates in vitro activity and early clinical trial shows marked antitumor activity in ROS1-rearranged patients. The overall response rate is around 56% and the disease control rate at 8 weeks is about 76%. Further understanding the ROS1 fusions in the pathogenesis of NSCLC, methods to detect ROS1 rearrangements, and targeting ROS1-rearranged NSCLC patients with specific kinase inhibitors would lead to an era of personalized medicine.

Luting XU

2013-12-01

186

Oleanane Triterpenoid CDDO-Me Inhibits Growth and Induce Apoptosis in Prostate Cancer Cells through a ROS-dependent Mechanism  

Digital Repository Infrastructure Vision for European Research (DRIVER)

CDDO-Me, a synthetic triterpenoid derived from oleanolic acid, is a promising anticancer agent that has shown strong activity against a wide variety cancer types in vitro and in vivo. We have previously shown that CDDO-Me induces apoptosis in prostate cancer cells irrespective of their hormonal status. To further understand the proapoptotic mechanism of CDDO-Me, we investigated the role of reactive oxygen species (ROS) in mediating the apoptosis inducing activity of CDDO-Me in LNCaP and PC-3 ...

Deeb, Dorrah; Gao, Xiaohua; Jiang, Hao; Janic, Branislava; Arbab, Ali S.; Rojanasakul, Yon; Dulchavsky, Scott A.; Gautam, Subhash C.

2010-01-01

187

New insights into an old story: Pollen ROS also play a role in hay fever  

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Reactive oxygen species (ROS) can exhibit negative and benign traits. In plants, ROS levels increase markedly during periods of environmental stress, and defense against pathogen attack. ROS form naturally as a by-product of normal oxygen metabolism, and evenly play an essential role in cell growth. The short ROS lifespan makes them ideal molecules to act in cell signaling, a role they share in both plants and animals. A particular plant organism, the pollen grain, may closely interact with h...

Speranza, Anna; Scoccianti, Valeria

2012-01-01

188

Fenretinide induces mitochondrial ROS and inhibits the mitochondrial respiratory chain in neuroblastoma  

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Fenretinide induces apoptosis in neuroblastoma by induction of reactive oxygen species (ROS). In this study, we investigated the role of mitochondria in fenretinide-induced cytotoxicity and ROS production in six neuroblastoma cell lines. ROS induction by fenretinide was of mitochondrial origin, demonstrated by detection of superoxide with MitoSOX, the scavenging effect of the mitochondrial antioxidant MitoQ and reduced ROS production in cells without a functional mitochondrial respiratory cha...

Cuperus, R.; Leen, R.; Tytgat, G. A. M.; Caron, H. N.; Kuilenburg, A. B. P.

2010-01-01

189

ROS1 gene rearrangement and copy number gain in non-small cell lung cancer.  

Science.gov (United States)

ROS1 has attracted much attention as a possible oncogenic driver and ROS1-rearranged tumors show sensitivity to most ALK inhibitors. We aimed to clarify the prevalence of ROS1 gene rearrangement and investigate the clinical implications of ROS1 gene copy number gain (CNG) in non-small cell lung cancer (NSCLC) patients. We carried out fluorescent in situ hybridization with ROS1 and centromere enumeration 6 probes and immunohistochemistry for ROS1 protein expression. ROS1 rearrangement was detected in 3 of 375 samples (0.8 %); all of whom were female, never-smokers, and harbored an adenocarcinoma component. ROS1 gene CNG was found in 18 cases (4.8 %). ROS1 gene CNG was significantly associated with shorter disease-free survival (DFS, 12 vs. 58 months; p?=?0.003) and shorter overall survival (OS, 40 vs. 67 months; p CNG. Multivariate analysis confirmed that ROS1 gene CNG was significantly associated with poorer DFS (hazard ratio [HR]=2.16, 95 % confidence interval [CI]?=?1.22-3.81, p?=?0.008), and OS ([HR]?=?2.53, 95 % [CI]?=?1.31-4.89, p?=?0.006). ROS1 protein overexpression was observed in 5.0 % (18 out of 357), of which 2 cases harbored ROS1 gene rearrangement. There was no statistically significant correlation between ROS1 gene CNG and protein overexpression. This study demonstrated ROS1 gene rearrangement was detected in 0.8 % of surgically resected NSCLC; and ROS1 gene CNG is an independent poor prognostic factor. This survival analyses may contribute to future studies on the utility of ROS1-targeted therapy for patients. PMID:25374304

Jin, Yan; Sun, Ping-Li; Kim, Hyojin; Park, Eunhyang; Shim, Hyo Sup; Jheon, Sanghoon; Kim, Kwhanmien; Lee, Choon-Taek; Chung, Jin-Haeng

2015-01-01

190

Heat stress induces ROS production and histone phosphorylation in celomocytes of Eisenia hortensis  

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The effect of heat stress on celomocytes (leukocytes) from Eisenia hortensis was investigated by measuring the production of reactive oxygen species (ROS). After culturing celomocytes at temperatures ranging from 4 °C (control) to 44 °C for 3-16 h, ROS levels were measured using a flow cytometric method employing dihydrorhodamine 123 (DHR123) for ROS detection and 7-aminoactinomycin D (7-AAD) as a viability stain. Reproducibly we observed significant (p < 0.05) increases in ROS production a...

Ra, Tumminello; Sl, Fuller-espie

2013-01-01

191

The role of mitochondrial complex III in melatonin induced ROS production in cultured mesangial cells  

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Melatonin is a potent scavenger of reactive oxygen (ROS) and reactive nitrogen species (RNS). At pharmacological concentrations, however, melatonin is documented to cause ROS/RNS production, especially in cultured cancerous cells. Currently, the mechanism responsible for melatonin-induced ROS generation remains elusive. In this study, we provide evidence that melatonin, at micromolar concentrations induced rapid ROS generation by a mitochondrial dependent mechanism in primary human mesangial ...

Zhang, Hong-mei; Zhang, Yi-qiang; Zhang, Bin-xian

2010-01-01

192

Oleanane triterpenoid CDDO-Me inhibits growth and induces apoptosis in prostate cancer cells through a ROS-dependent mechanism.  

Science.gov (United States)

CDDO-Me, a synthetic triterpenoid derived from oleanolic acid, is a promising anticancer agent that has shown strong activity against a wide variety of cancer types in vitro and in vivo. We have previously shown that CDDO-Me induces apoptosis in prostate cancer cells irrespective of their hormonal status. To further understand the proapoptotic mechanism of CDDO-Me, we investigated the role of reactive oxygen species (ROS) in mediating the apoptosis inducing activity of CDDO-Me in LNCaP and PC-3 prostate cancer cell lines. Here, we show that CDDO-Me induces ROS generation from both nonmitochondrial and mitochondrial sources, which is associated with the induction of apoptosis as characterized by increased annexin V-binding, cleavage of PARP-1 and procaspases-3, -8, -9, loss of mitochondrial membrane potential and release of cytochrome c. In addition, CDDO-Me inhibited cell survival Akt, NF-kappaB and mTOR signaling proteins. The inhibition of ROS generation by N-acetylcysteine (NAC) or by overexpression of antioxidant enzymes glutathione peroxidase (GPx) and superoxide dismutase-1 (SOD-1) prevented CDDO-Me-induced apoptosis. Pretreatment with NAC blocked annexin V-binding, cleavage of PARP-1 and procaspases-3, -8, -9, loss of mitochondrial membrane potential and release of cytochrome c by CDDO-Me. NAC also prevented the inhibition of constitutively active Akt, NF-kappaB and mTOR by CDDO-Me. Together, these data indicate that ROS plays an essential role in the induction of apoptosis by CDDO-Me in prostate cancer cells. PMID:19782051

Deeb, Dorrah; Gao, Xiaohua; Jiang, Hao; Janic, Branislava; Arbab, Ali S; Rojanasakul, Yon; Dulchavsky, Scott A; Gautam, Subhash C

2010-02-01

193

Oleanane Triterpenoid CDDO-Me Inhibits Growth and Induce Apoptosis in Prostate Cancer Cells through a ROS-dependent Mechanism  

Science.gov (United States)

CDDO-Me, a synthetic triterpenoid derived from oleanolic acid, is a promising anticancer agent that has shown strong activity against a wide variety cancer types in vitro and in vivo. We have previously shown that CDDO-Me induces apoptosis in prostate cancer cells irrespective of their hormonal status. To further understand the proapoptotic mechanism of CDDO-Me, we investigated the role of reactive oxygen species (ROS) in mediating the apoptosis inducing activity of CDDO-Me in LNCaP and PC-3 prostate cancer cell lines. Here, we show that CDDO-Me induces ROS generation from both nonmitochondrial and mitochondrial sources, which is associated with induction of apoptosis as characterized by increased annexin V-binding, cleavage of PARP-1 and procaspases -3,-8, -9, loss of mitochondrial membrane potential and release of cytochrome c. In addition, CDDO-Me inhibited cell survival Akt, NF-?B and mTOR signaling proteins. The inhibition of ROS generation by N-acetylcysteine (NAC) or by overexpression of antioxidant enzymes glutathione peroxidase (GPx) and superoxide dismutase1 (SOD1) prevented CDDO-Me-induced apoptosis. Pretreatment with NAC blocked annexin V-binding, cleavage of PARP-1 and procaspases -3,-8, -9, loss of mitochondrial membrane potential and release of cytochrome c by CDDO-Me. NAC also prevented the inhibition of constitutively active Akt, NF-?B and mTOR by CDDO-Me. Together, these data indicate that ROS plays an essential role in induction of apoptosis by CDDO-Me in prostate cancer cells. PMID:19782051

Deeb, Dorrah; Gao, Xiaohua; Jiang, Hao; Janic, Branislava; Arbab, Ali S.; Rojanasakul, Yon; Dulchavsky, Scott A.; Gautam, Subhash C.

2009-01-01

194

Gravitropic response induced by coumarin: Evidences of ROS distribution involvement  

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Coumarin effects on gravitropic responses of Arabidopsis thaliana roots were here evaluated. Coumarin alone did not cause any alteration on gravitropic response showing a behavior similar to control plants. In contrast, TIBA and NPA, two auxin transport inhibitors, strongly modified root gravitropic responses. The addition of coumarin to the medium together with TIBA or NPA partially restored the effect of both inhibitors. Simultaneously, a semi-quantitative evaluation of ROS distribution was...

Lupini, Antonio; Araniti, Fabrizio; Sunseri, Francesco; Abenavoli, Maria Rosa

2013-01-01

195

Overview of ALK and ROS1 Rearranged Lung Cancer  

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Many attempts have been made to find genetic abnormalities inducing carcinogenesis after the development of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor targeting EGFR in lung cancer. New target therapies have been already commercialized and studied along with the recent discovery of gene rearrangement involved in the carcinogenic process of non-small cell lung cancer. This study aims to investigate anplastic lymphoma kinase, c-ros oncogene 1, and receptor tyrosine kinase...

Choi, Chang Min

2013-01-01

196

p53, ROS and senescence in the control of aging  

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Abstract: In addition to its function as a tumour suppressor, p53 is also involved in an increasing number of pathology associated with aging. Several activities of p53 appear contribute to its role in aging; one function that might be particularly relevant in this context is the regulation of senescence. The control of ROS and senescence by p53 may help to explain how p53 can function ...

Vigneron, Arnaud; Vousden, Karen H.

2010-01-01

197

MicroRNA-145 suppresses ROS-induced Ca{sup 2+} overload of cardiomyocytes by targeting CaMKII?  

Energy Technology Data Exchange (ETDEWEB)

Highlights: •CaMKII? mediates H{sub 2}O{sub 2}-induced Ca{sup 2+} overload in cardiomyocytes. •miR-145 can inhibit Ca{sup 2+} overload. •A luciferase assay confirms that miR-145 functions as a CaMKII?-targeting miRNA. •Overexpression of miR-145 regulates CaMKII?-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca{sup 2+}) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca{sup 2+} signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca{sup 2+}-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H{sub 2}O{sub 2}-mediated Ca{sup 2+} overload, we selected and tested 6 putative miRNAs that targeted CaMKII?, and showed that miR-145 represses CaMKII? protein expression and Ca{sup 2+} overload. We confirmed CaMKII? as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca{sup 2+}-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca{sup 2+} overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses.

Cha, Min-Ji [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jang, Jin-Kyung [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Lee, Chang Yeon; Park, Jun-Hee [Department of Integrated Omics for Biomedical Sciences, Graduate School, Yonsei University, 50 Yonsei-ro, Seodamun-gu, Seoul 120-759 (Korea, Republic of); Lee, Jiyun; Seo, Hyang-Hee [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Choi, Eunhyun [Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University Health System, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jeon, Woo-min [Department of Animal Resource, Sahmyook University, Seoul 139-742 (Korea, Republic of); Hwang, Hye Jin [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Shin, Hyun-Taek [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); and others

2013-06-14

198

MicroRNA-145 suppresses ROS-induced Ca2+ overload of cardiomyocytes by targeting CaMKII?  

International Nuclear Information System (INIS)

Highlights: •CaMKII? mediates H2O2-induced Ca2+ overload in cardiomyocytes. •miR-145 can inhibit Ca2+ overload. •A luciferase assay confirms that miR-145 functions as a CaMKII?-targeting miRNA. •Overexpression of miR-145 regulates CaMKII?-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca2+) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca2+ signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca2+-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H2O2-mediated Ca2+ overload, we selected and tested 6 putative miRNAs that targeted CaMKII?, and showed that miR-145 represses CaMKII? protein expression and Ca2+ overload. We confirmed CaMKII? as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca2+-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca2+ overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses

199

Effect of Methyl Jasmonate on antioxidative enzyme activities and on the contents of ROS and H2O2 in Ricinus communis leaves  

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Jasmonates are a class of plant hormones that mediate various aspects in gene and metabolic regulation, defense, stress responses, reproduction and, possibly, communication. Oxidative stress stimulates synthesis of antioxidant metabolites and enhances antioxidant enzyme activities that could protect plant tissues. The aim of this study was to verify the effects of methyl jasmonate (JAME) treatment on the reactive oxygen species (ROS) and on the activities of H2O2 scavenging enzymes, such as s...

Alexandra Martins dos Santos Soares; Thiago Freitas de Souza; Tânia Jacinto; Olga Lima Tavares Machado

2010-01-01

200

Antioxidants successfully reduce ROS production in propionic acidemia fibroblasts.  

Science.gov (United States)

Propionic acidemia (PA), caused by a deficiency of the mitochondrial biotin dependent enzyme propionyl-CoA carboxylase (PCC) is one of the most frequent organic acidurias in humans. Most PA patients present in the neonatal period with metabolic acidosis and hyperammonemia, developing different neurological symptoms, movement disorders and cardiac complications. There is strong evidence indicating that oxidative damage could be a pathogenic factor in neurodegenerative, mitochondrial and metabolic diseases. Recently, we identified an increase in ROS levels in PA patients-derived fibroblasts. Here, we analyze the capability of seven antioxidants to scavenge ROS production in PA patients' cells. Tiron, trolox, resveratrol and MitoQ significantly reduced ROS content in patients and controls' fibroblasts. In addition, changes in the expression of two antioxidant enzymes, superoxide dismutase and glutathione peroxidase, were observed in PA patients-derived fibroblasts after tiron and resveratrol treatment. Our results in PA cellular models establish the proof of concept of the potential of antioxidants as an adjuvant therapy for PA and pave the way for future assessment of antioxidant strategies in the murine model of PA. PMID:25159844

Gallego-Villar, Lorena; Pérez, Belén; Ugarte, Magdalena; Desviat, Lourdes R; Richard, Eva

2014-09-26

 
 
 
 
201

The Affordance Template ROS Package for Robot Task Programming  

Science.gov (United States)

This paper introduces the Affordance Template ROS package for quickly programming, adjusting, and executing robot applications in the ROS RViz environment. This package extends the capabilities of RViz interactive markers by allowing an operator to specify multiple end-effector waypoint locations and grasp poses in object-centric coordinate frames and to adjust these waypoints in order to meet the run-time demands of the task (specifically, object scale and location). The Affordance Template package stores task specifications in a robot-agnostic XML description format such that it is trivial to apply a template to a new robot. As such, the Affordance Template package provides a robot-generic ROS tool appropriate for building semi-autonomous, manipulation-based applications. Affordance Templates were developed by the NASA-JSC DARPA Robotics Challenge (DRC) team and have since successfully been deployed on multiple platforms including the NASA Valkyrie and Robonaut 2 humanoids, the University of Texas Dreamer robot and the Willow Garage PR2. In this paper, the specification and implementation of the affordance template package is introduced and demonstrated through examples for wheel (valve) turning, pick-and-place, and drill grasping, evincing its utility and flexibility for a wide variety of robot applications.

Hart, Stephen; Dinh, Paul; Hambuchen, Kimberly

2015-01-01

202

Identifying and Targeting ROS1 Gene Fusions in Non-Small Cell Lung Cancer  

Science.gov (United States)

Purpose Oncogenic gene fusions involving the 3’ region of ROS1 kinase have been identified in various human cancers. In this study, we sought to characterize ROS1 fusion genes in non-small cell lung cancer (NSCLC) and establish the fusion proteins as drug targets. Experimental Design A NSCLC tissue microarray (TMA) panel containing 447 samples was screened for ROS1 rearrangement by fluorescence in-situ hybridization (FISH). This assay was also used to screen NSCLC patients. In positive samples, the identity of the fusion partner was determined through inverse-PCR and RT-PCR. In addition, the clinical utility of ROS1 inhibition was assessed by treating a ROS1-positive patient with crizotinib. The HCC78 cell line, which expresses the SLC34A2-ROS1 fusion, was treated with kinase inhibitors that have activity against ROS1. The effects of ROS1 inhibition on proliferation, cell-cycle progression, and cell signaling pathways were analyzed by MTS assay, flow cytometry, and western blotting. Results In the TMA panel, 5/428 (1.2%) evaluable samples were found to be positive for ROS1 rearrangement. Additionally, 1/48 patients tested positive for rearrangement, and this patient demonstrated tumor shrinkage upon treatment with crizotinib. The patient and one TMA sample displayed expression of the recently identified SDC4-ROS1 fusion, while two TMA samples expressed the CD74-ROS1 fusion and two others expressed the SLC34A2-ROS1 fusion. In HCC78 cells, treatment with ROS1 inhibitors was anti-proliferative and down-regulated signaling pathways that are critical for growth and survival. Conclusions ROS1 inhibition may be an effective treatment strategy for the subset of NSCLC patients whose tumors express ROS1 fusion genes. PMID:22919003

Davies, Kurtis D.; Le, Anh T.; Theodoro, Mariana F.; Skokan, Margaret C.; Aisner, Dara L.; Berge, Eamon M.; Terracciano, Luigi M.; Incarbone, Matteo; Roncalli, Massimo; Cappuzzo, Federico; Camidge, D. Ross; Varella-Garcia, Marileila; Doebele, Robert C.

2013-01-01

203

C. elegans epidermal wounding induces a mitochondrial ROS burst that promotes wound repair.  

Science.gov (United States)

Reactive oxygen species (ROS) such as hydrogen peroxide are generated at wound sites and act as long-range signals in wound healing. The roles of other ROS in wound repair are little explored. Here, we reveal a cytoprotective role for mitochondrial ROS (mtROS) in Caenorhabditis elegans skin wound healing. We show that skin wounding causes local production of mtROS superoxide at the wound site. Inhibition of mtROS levels by mitochondrial superoxide-specific antioxidants blocks actin-based wound closure, whereas elevation of mtROS promotes wound closure and enhances survival of mutant animals defective in wound healing. mtROS act downstream of wound-triggered Ca(2+) influx. We find that the mitochondrial calcium uniporter MCU-1 is essential for rapid mitochondrial Ca(2+) uptake and mtROS production after wounding. mtROS can promote wound closure by local inhibition of Rho GTPase activity via a redox-sensitive motif. These findings delineate a pathway acting via mtROS that promotes cytoskeletal responses in wound healing. PMID:25313960

Xu, Suhong; Chisholm, Andrew D

2014-10-13

204

Metal-Sulfate Induced Generation of ROS in Human Brain Cells: Detection Using an Isomeric Mixture of 5- and 6-Carboxy-2?,7?-Dichlorofluorescein Diacetate (Carboxy-DCFDA as a Cell Permeant Tracer  

Directory of Open Access Journals (Sweden)

Full Text Available Evolution of reactive oxygen species (ROS, generated during the patho-physiological stress of nervous tissue, has been implicated in the etiology of several progressive human neurological disorders including Alzheimer’s disease (AD and amylotrophic lateral sclerosis (ALS. In this brief communication we used mixed isomers of 5-(and-6-carboxy-2?,7?-dichlorofluorescein diacetate (carboxy-DCFDA; C25H14Cl2O9; MW 529.3, a novel fluorescent indicator, to assess ROS generation within human neuronal-glial (HNG cells in primary co-culture. We introduced pathological stress using the sulfates of 12 environmentally-, industrially- and agriculturally-relevant divalent and trivalent metals including Al, Cd, Cu, Fe, Hg, Ga, Mg, Mn, Ni, Pb, Sn and Zn. In this experimental test system, of all the metal sulfates analyzed, aluminum sulfate showed by far the greatest ability to induce intracellular ROS. These studies indicate the utility of using isomeric mixtures of carboxy-H2DCFDA diacetates as novel and highly sensitive, long-lasting, cell-permeant, fluorescein-based tracers for quantifying ROS generation in intact, metabolizing human brain cells, and in analyzing the potential epigenetic contribution of different metal sulfates to ROS-generation and ROS-mediated neurological dysfunction.

Walter J. Lukiw

2012-08-01

205

Redirecting apoptosis to aponecrosis induces selective cytotoxicity to pancreatic cancer cells through increased ROS, decline in ATP levels, and VDAC.  

Science.gov (United States)

Pancreatic cancer cell lines with mutated ras underwent an alternative form of cell death (aponecrosis) when treated concomitantly with clinically achievable concentrations of arsenic trioxide, ascorbic acid, and disulfiram (Antabuse; AAA). AAA's major effects are mediated through generation of intracellular reactive oxygen species (ROS) and more than 50% decline in intracellular ATP. N-acetyl cysteine and a superoxide dismutase mimetic prevented aponecrosis and restored intracellular ATP levels. DIDS (4,4'-diisothiocyanatostilbene-2, 2' disulfonic acid), the pan- Voltage-Dependent Anion Channel (VDAC), -1, 2, 3 inhibitor and short hairpin RNA (shRNA) to VDAC-1 blocked cell death and ROS accumulation. In vivo exposure of AAA led to a 62% reduction in mean tumor size and eliminated tumors in 30% of nude mice with PANC-1 xenografts. We concluded that early caspase-independent apoptosis was shifted to VDAC-mediated "targeted" aponecrosis by the addition of disulfiram to arsenic trioxide and ascorbic acid. Conceptually, this work represents a paradigm shift where switching from apoptosis to aponecrosis death pathways, also known as targeted aponecrosis, could be utilized to selectively kill pancreatic cancer cells resistant to apoptosis. PMID:24126434

Dinnen, Richard D; Mao, Yuehua; Qiu, Wanglong; Cassai, Nicholas; Slavkovich, Vesna N; Nichols, Gwen; Su, Gloria H; Brandt-Rauf, Paul; Fine, Robert L

2013-12-01

206

Ursolic acid induces autophagy in U87MG cells via ROS-dependent endoplasmic reticulum stress.  

Science.gov (United States)

Malignant gliomas are the most common primary brain tumors, and novel ways of treating gliomas are urgently needed. Ursolic acid (UA), a pentacyclic triterpenoid, has been reported to exhibit promising antitumor activity. Here, we evaluated the effects of UA on U87MG cells and explored the underlying molecular mechanisms. The results demonstrated that both G1-phase arrest and autophagy were induced by UA in U87MG cells. Evidence of UA-induced autophagy included the formation of acidic vesicular organelles, increase of autophagolysosomes and LC3-II accumulation. UA was also found to induce ER stress and an increase in intracellular calcium accompanied by ROS production. The increase in free cytosolic calcium induced by UA activated the CaMKK-AMPK-mTOR kinase signaling cascade, which ultimately triggered autophagy. Western blot analysis showed that UA promoted the phosphorylation of PERK and eIF2?; this was followed by the upregulation of the downstream protein CHOP, implying the involvement of the ER stress-mediated PERK/eIF2?/CHOP pathway in glioma cells. Meanwhile, UA activated IRE1? and subsequently increased the levels of phosphorylated JNK and Bcl-2, resulting in the dissociation of Beclin1 from Bcl-2. Furthermore, TUDCA and the silencing of either PERK or IRE1? partially blocked the UA-induced accumulation of LC3-II, suggesting that ER stress precedes the process of autophagy. Additionally, NAC attenuated the UA-induced elevation in cytosolic calcium, ER stress markers and autophagy-related proteins, indicating that UA triggered ER stress and autophagy via a ROS-dependent pathway. Collectively, our findings revealed a novel cellular mechanism triggered by UA and provide a molecular basis for developing UA into a drug candidate. PMID:24802810

Shen, Shuying; Zhang, Yi; Zhang, Rui; Tu, Xintao; Gong, Xingguo

2014-07-25

207

Advanced Query and Data Mining Capabilities for MaROS  

Science.gov (United States)

The Mars Relay Operational Service (MaROS) comprises a number of tools to coordinate, plan, and visualize various aspects of the Mars Relay network. These levels include a Web-based user interface, a back-end "ReSTlet" built in Java, and databases that store the data as it is received from the network. As part of MaROS, the innovators have developed and implemented a feature set that operates on several levels of the software architecture. This new feature is an advanced querying capability through either the Web-based user interface, or through a back-end REST interface to access all of the data gathered from the network. This software is not meant to replace the REST interface, but to augment and expand the range of available data. The current REST interface provides specific data that is used by the MaROS Web application to display and visualize the information; however, the returned information from the REST interface has typically been pre-processed to return only a subset of the entire information within the repository, particularly only the information that is of interest to the GUI (graphical user interface). The new, advanced query and data mining capabilities allow users to retrieve the raw data and/or to perform their own data processing. The query language used to access the repository is a restricted subset of the structured query language (SQL) that can be built safely from the Web user interface, or entered as freeform SQL by a user. The results are returned in a CSV (Comma Separated Values) format for easy exporting to third party tools and applications that can be used for data mining or user-defined visualization and interpretation. This is the first time that a service is capable of providing access to all cross-project relay data from a single Web resource. Because MaROS contains the data for a variety of missions from the Mars network, which span both NASA and ESA, the software also establishes an access control list (ACL) on each data record in the database repository to enforce user access permissions through a multilayered approach.

Wang, Paul; Wallick, Michael N.; Allard, Daniel A.; Gladden, Roy E.; Hy, Franklin H.

2013-01-01

208

A novel synthetic analog of militarin, MA-1 induces mitochondrial dependent apoptosis by ROS generation in human lung cancer cells  

International Nuclear Information System (INIS)

A synthetic Militarin analog-1[(2R,3R,4R,5R)-1,6-bis(4-(2,4,4-trimethylpentan-2-yl)phenoxy) hexane-2,3,4,5-tetraol] is a novel derivative of constituents from Cordyceps militaris, which has been used to treat a variety of chronic diseases including inflammation, diabetes, hyperglycemia and cancers. Here, we report for the first time the synthesis of Militarin analog-1 (MA-1) and the apoptotic mechanism of MA-1 against human lung cancer cell lines. Treatment with MA-1 significantly inhibited the viability of 3 human lung cancer cell lines. The inhibition of viability and growth in MA-1-treated A549 cells with an IC50 of 5 ?M were mediated through apoptosis induction, as demonstrated by an increase in DNA fragmentation, sub-G0/G1-DNA fraction, nuclear condensation, and phosphatidylserine exposure. The apoptotic cell death caused mitochondrial membrane permeabilization through regulation of expression of the Bcl-2 family proteins, leading to cytochrome c release in a time-dependent manner. Subsequently, the final stage of apoptosis, activation of caspase-9/-3 and cleavage of poly (ADP ribose) polymerase, was induced. Furthermore, A549 lung cancer cells were more responsive to MA-1 than a bronchial epithelial cell line (BEAS-2B), involving the rapid generation of reactive oxygen species (ROS), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) activation. The pharmacological inhibition of ROS generation and JNK/p38 MAPK exhibited attenuated DNA fragmentation in MA-1-induced apoptosis. Oral administration of MA-1 also retarded growth of A549 orthotopic xenografts. In conclusion, the present study indicates that the new synthetic derivative MA-1 triggers mitochondrial apoptosis through ROS generation and regulation of MAPKs and may be a potent therapeutic agent against human lung cancer. - Highlights: • We report a novel synthesized derivative, militarin analog-1 (MA-1). • MA-1-induced cancer cell death was triggered by the ROS generation through MAPKs. • The MA-1-induced cell death was also modulated by the mitochondria-mediated pathway. • The apoptotic cancer cell death by MA-1 was also exhibited in orthotopic xenografts. • Our findings suggest MA-1 as a clinically useful agent for human lung cancer

209

A novel synthetic analog of militarin, MA-1 induces mitochondrial dependent apoptosis by ROS generation in human lung cancer cells  

Energy Technology Data Exchange (ETDEWEB)

A synthetic Militarin analog-1[(2R,3R,4R,5R)-1,6-bis(4-(2,4,4-trimethylpentan-2-yl)phenoxy) hexane-2,3,4,5-tetraol] is a novel derivative of constituents from Cordyceps militaris, which has been used to treat a variety of chronic diseases including inflammation, diabetes, hyperglycemia and cancers. Here, we report for the first time the synthesis of Militarin analog-1 (MA-1) and the apoptotic mechanism of MA-1 against human lung cancer cell lines. Treatment with MA-1 significantly inhibited the viability of 3 human lung cancer cell lines. The inhibition of viability and growth in MA-1-treated A549 cells with an IC{sub 50} of 5 ?M were mediated through apoptosis induction, as demonstrated by an increase in DNA fragmentation, sub-G{sub 0}/G{sub 1}-DNA fraction, nuclear condensation, and phosphatidylserine exposure. The apoptotic cell death caused mitochondrial membrane permeabilization through regulation of expression of the Bcl-2 family proteins, leading to cytochrome c release in a time-dependent manner. Subsequently, the final stage of apoptosis, activation of caspase-9/-3 and cleavage of poly (ADP ribose) polymerase, was induced. Furthermore, A549 lung cancer cells were more responsive to MA-1 than a bronchial epithelial cell line (BEAS-2B), involving the rapid generation of reactive oxygen species (ROS), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) activation. The pharmacological inhibition of ROS generation and JNK/p38 MAPK exhibited attenuated DNA fragmentation in MA-1-induced apoptosis. Oral administration of MA-1 also retarded growth of A549 orthotopic xenografts. In conclusion, the present study indicates that the new synthetic derivative MA-1 triggers mitochondrial apoptosis through ROS generation and regulation of MAPKs and may be a potent therapeutic agent against human lung cancer. - Highlights: • We report a novel synthesized derivative, militarin analog-1 (MA-1). • MA-1-induced cancer cell death was triggered by the ROS generation through MAPKs. • The MA-1-induced cell death was also modulated by the mitochondria-mediated pathway. • The apoptotic cancer cell death by MA-1 was also exhibited in orthotopic xenografts. • Our findings suggest MA-1 as a clinically useful agent for human lung cancer.

Yoon, Deok Hyo; Lim, Mi-Hee [Department of Biochemistry, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Lee, Yu Ran [Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of); Sung, Gi-Ho [Mushroom Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Suwon 404-707 (Korea, Republic of); Lee, Tae-Ho [R and D Center, Dong-A Pharmaceutical Co, Ltd, Yongin 446-905 (Korea, Republic of); Jeon, Byeong Hwa [Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of); Cho, Jae Youl [Department of Genetic Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Song, Won O. [Department of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824 (United States); Park, Haeil [College of Pharmacy, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Choi, Sunga, E-mail: sachoi@cnu.ac.kr [Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747 (Korea, Republic of); Kim, Tae Woong, E-mail: tawkim@kangwon.ac.kr [Department of Biochemistry, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

2013-12-15

210

Angiotensin II–Mediated Oxidative DNA Damage Accelerates Cellular Senescence in Cultured Human Vascular Smooth Muscle Cells via Telomere-Dependent and Independent Pathways  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Angiotensin II (Ang II) induces reactive oxygen species (ROS) production by human vascular smooth muscle cells (hVSMCs). ROS have been implicated in the development of both acute stress-induced premature senescence (SIPS) and chronic replicative senescence. Global oxidative DNA damage triggers SIPS and telomere DNA damage accelerates replicative senescence, both mediated via p53. This study tests the hypothesis that DNA is an important target for Ang II–induced ROS leading to senescence via...

Herbert, Karl E.; Mistry, Yogita; Hastings, Richard; Poolman, Toryn; Niklason, Laura; Williams, Bryan

2008-01-01

211

Deficient autophagy unravels the ROS paradox in chronic granulomatous disease.  

Science.gov (United States)

Autophagy defects resulting in inflammation appear to be a key feature in the pathogenesis of Crohn colitis. An inflammatory colitis indistinguishable from Crohn disease is described in patients with chronic granulomatous disease (CGD). Patients with CGD have a mutated NADPH complex and are therefore deficient in reactive oxygen species (ROS) production; however, the underlying mechanism for the inflammatory colitis in CGD remained unknown. In a recent study, our group reported that NADPH-dependent ROS deficiency results in autophagic dysfunction that subsequently contributes to increased IL1B/interleukin 1? production. Mice deficient in the NADPH-complex component NCF4/p40phox, and CGD patients with a defect in NCF4 display minimal recruitment of LC3 to phagosomes in response to internalized bacteria and fungi. Human monocytes from patients with CGD with defective LC3 recruitment show increased IL1B production after LPS stimulation. Blocking IL1 protects NCF4-deficient mice from experimental colitis; importantly, improved clinical outcome in 2 CGD patients with colitis is also observed with IL1 blockade. Moreover, blocking IL1 restores defective autophagy in CGD mice and cells from patients with CGD. Thus, autophagic dysfunction underlies the pathogenesis of granulomatous colitis in CGD, and blocking IL1 can be used to treat CGD colitis. PMID:24879159

van de Veerdonk, Frank L; Dinarello, Charles A

2014-06-01

212

Free Radicals Mediate Systemic Acquired Resistance  

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Full Text Available Systemic acquired resistance (SAR is a form of resistance that protects plants against a broad spectrum of secondary infections. However, exploiting SAR for the protection of agriculturally important plants warrants a thorough investigation of the mutual interrelationships among the various signals that mediate SAR. Here, we show that nitric oxide (NO and reactive oxygen species (ROS serve as inducers of SAR in a concentration-dependent manner. Thus, genetic mutations that either inhibit NO/ROS production or increase NO accumulation (e.g., a mutation in S-nitrosoglutathione reductase [GSNOR] abrogate SAR. Different ROS function additively to generate the fatty-acid-derived azelaic acid (AzA, which in turn induces production of the SAR inducer glycerol-3-phosphate (G3P. Notably, this NO/ROS?AzA?G3P-induced signaling functions in parallel with salicylic acid-derived signaling. We propose that the parallel operation of NO/ROS and SA pathways facilitates coordinated regulation in order to ensure optimal induction of SAR.

Caixia Wang

2014-04-01

213

Free radicals mediate systemic acquired resistance.  

Science.gov (United States)

Systemic acquired resistance (SAR) is a form of resistance that protects plants against a broad spectrum of secondary infections. However, exploiting SAR for the protection of agriculturally important plants warrants a thorough investigation of the mutual interrelationships among the various signals that mediate SAR. Here, we show that nitric oxide (NO) and reactive oxygen species (ROS) serve as inducers of SAR in a concentration-dependent manner. Thus, genetic mutations that either inhibit NO/ROS production or increase NO accumulation (e.g., a mutation in S-nitrosoglutathione reductase [GSNOR]) abrogate SAR. Different ROS function additively to generate the fatty-acid-derived azelaic acid (AzA), which in turn induces production of the SAR inducer glycerol-3-phosphate (G3P). Notably, this NO/ROS?AzA?G3P-induced signaling functions in parallel with salicylic acid-derived signaling. We propose that the parallel operation of NO/ROS and SA pathways facilitates coordinated regulation in order to ensure optimal induction of SAR. PMID:24726369

Wang, Caixia; El-Shetehy, Mohamed; Shine, M B; Yu, Keshun; Navarre, Duroy; Wendehenne, David; Kachroo, Aardra; Kachroo, Pradeep

2014-04-24

214

The alternative Medicago truncatula defense proteome of ROS—defective transgenic roots during early microbial infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ROP-type GTPases of plants function as molecular switches within elementary signal transduction pathways such as the regulation of ROS synthesis via activation of NADPH oxidases (RBOH-respiratory burst oxidase homolog in plants). Previously, we reported that silencing of the Medicago truncatula GTPase MtROP9 led to reduced ROS production and suppressed induction of ROS-related enzymes in transgenic roots (MtROP9i) infected with pathogenic (Aphanomyces euteiches) and symbiotic microorganisms (...

Kiirika, Leonard M.; Schmitz, Udo; Colditz, Frank

2014-01-01

215

Hyperoxygenation Attenuated a Murine Model of Atopic Dermatitis through Raising Skin Level of ROS  

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Atopic dermatitis (AD) is a chronic inflammatory skin disease resulting from excessive stimulation of immune cells. Traditionally, reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases, but several opposing observations suggest the protective role of ROS in inflammatory disease. Recently, we demonstrated ROS prevented imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function. Thus, we hypothesized AD might also be attenuated i...

Kim, Hyung-ran; Kim, Jung-hwan; Choi, Eun-jeong; Lee, Yeo Kyong; Kie, Jeong-hae; Jang, Myoung Ho; Seoh, Ju-young

2014-01-01

216

ROS-GC interlocked Ca2+-sensor S100B protein signaling in cone photoreceptors: Review  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Photoreceptor rod outer segment membrane guanylate cyclase (ROS-GC) is central to visual transduction; it generates cyclic GMP, the second messenger of the photon signal. Photoexcited rhodopsin initiates a biochemical cascade that leads to a drop in the intracellular level of cyclic GMP and closure of cyclic nucleotide gated ion channels. Recovery of the photoresponse requires resynthesis of cyclic GMP, typically by a pair of ROS-GCs, 1 and 2. In rods, ROS-GCs exist as complexes with guanylat...

Sharma, Rameshwar K.; Makino, Clint L.; Teresa Duda; David Hicks

2014-01-01

217

Characterization of ROS1 cDNA from a human glioblastoma cell line  

International Nuclear Information System (INIS)

The authors have isolated and characterized a human ROS1 cDNA from the glioblastoma cell line SW-1088. The cDNA, 8.3 kilobases long, has the potential to encode a transmembrane tyrosine-specific protein kinase with a predicted molecular mass of 259 kDa. The putative extracellular domain of ROS1 is homologous to the extracellular domain of the sevenless gene product from Drosophila. No comparable similarities in the extracellular domains were found between ROS1 and other receptor-type tyrosine kinases. Together, ROS1 and sevenless gene products define a distinct subclass of transmember tyrosine kinases

218

Rho GTPases and Nox dependent ROS production in skin. Is there a connection?  

DEFF Research Database (Denmark)

Rho GTPases are a family of small GTP binding proteins most commonly known for the regulation of many cellular processes, including actin cytoskeleton re-organisation, cell proliferation, signal transduction and regulation of apoptosis. Additionally, a link between Rho GTPases and reactive oxygen species (ROS) has been shown. In line with the growing interest in the role of ROS in cell biology, the relevance of this connection is becoming increasingly clearer. ROS production is classically associated with oxidative metabolic pathways (e.g. respiratory chain, arachidonic acid). During these metabolic pathways, ROS are produced as by-products and these can be potentially toxic. However, numerous cell types contain dedicated enzymatic complexes, i.e., NADPH oxidase (Nox) complexes, for regulated production of ROS. This regulated production of ROS seems to be important for a number of fundamental cell biological processes, including cell growth, differentiation, migration, angiogenesis, aimed at maintaining tissue homeostasis. Data suggests that skin cells are capable of a regulated ROS production via Nox complexes. Members of the Rho GTPase family have been found to play a central regulatory role in Nox activity. In the present review we will focus on the involvement of Rho GTPases in regulated production of ROS with special emphasis on the skin. We will also discuss the possibility that some in vivo effects of the deletion of members of the Rho GTPase family in skin cells could potentially be linked to a reduced ability of regulated ROS production.

Stanley, Alanna; Hynes, Ailish

2012-01-01

219

Expression and rearrangement of the ROS1 gene in human glioblastoma cells  

International Nuclear Information System (INIS)

The human ROS1 gene, which possibly encodes a growth factor receptor, was found to be expressed in human tumor cell lines. In a survey of 45 different human cell lines, the authors found ROS1 to be expressed in glioblastoma-derived cell lines at high levels and not to be expressed at all, or expressed at very low levels, in the remaining cell lines. The ROS1 gene was present in normal copy numbers in all cell lines that expressed the gene. However, in one particular glioblastoma line, they detected a potentially activating mutation at the ROS1 locus

220

Effect of Methyl Jasmonate on antioxidative enzyme activities and on the contents of ROS and H2O2 in Ricinus communis leaves  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Jasmonates are a class of plant hormones that mediate various aspects in gene and metabolic regulation, defense, stress responses, reproduction and, possibly, communication. Oxidative stress stimulates synthesis of antioxidant metabolites and enhances antioxidant enzyme activities that could protect [...] plant tissues. The aim of this study was to verify the effects of methyl jasmonate (JAME) treatment on the reactive oxygen species (ROS) and on the activities of H2O2 scavenging enzymes, such as superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX EC; 1.11.1.1), and guaiacol peroxidase (GPX; EC 1.11.1.7) in Ricinus communis leaves. The activity of CAT and GPX was transient while SOD activity decreased and APX increased after treatment with JAME. In addition, JAME exposure induced ROS accumulation.

Alexandra Martins dos Santos, Soares; Thiago Freitas de, Souza; Tânia, Jacinto; Olga Lima Tavares, Machado.

 
 
 
 
221

Effect of Methyl Jasmonate on antioxidative enzyme activities and on the contents of ROS and H2O2 in Ricinus communis leaves  

Directory of Open Access Journals (Sweden)

Full Text Available Jasmonates are a class of plant hormones that mediate various aspects in gene and metabolic regulation, defense, stress responses, reproduction and, possibly, communication. Oxidative stress stimulates synthesis of antioxidant metabolites and enhances antioxidant enzyme activities that could protect plant tissues. The aim of this study was to verify the effects of methyl jasmonate (JAME treatment on the reactive oxygen species (ROS and on the activities of H2O2 scavenging enzymes, such as superoxide dismutase (SOD; EC 1.15.1.1, catalase (CAT; EC 1.11.1.6, ascorbate peroxidase (APX EC; 1.11.1.1, and guaiacol peroxidase (GPX; EC 1.11.1.7 in Ricinus communis leaves. The activity of CAT and GPX was transient while SOD activity decreased and APX increased after treatment with JAME. In addition, JAME exposure induced ROS accumulation.

Alexandra Martins dos Santos Soares

2010-01-01

222

Effects of osteotropic hormones on the nitric oxide production in culture of ROS17/2.8 cells  

Energy Technology Data Exchange (ETDEWEB)

We performed the present study to investigate whether osteotropic hormones play roles on the nitric oxide (NO) production in culture of ROS17/2.8 osteoblastic cells. The osteoblastic cell line ROS17/2.8 cells were cultured in F12 medium supplemented with 5% fetal bovine serum (FBS) at 37.deg. C in a humidified atmosphere of 5% CO{sub 2} in air. ROS17/2.8 cells were plated in 96-well plants at a density of 2-3 x 10{sup 3} cells/well and grown to confluence. Then the cells were pretreated with osteotropic hormones (parathyroid hormone (PTH) 20-500 ng/mL, 1, 25-dihydroxycholecalciferol (1, 25[OH]{sub 2}D{sub 3}) 1-100nM ; prostaglandin E{sub 2}(PGE{sub 2}) 20-500 ng/mL) in the medium supplemented with 0.4% FBS for (72 hours and the cells were treated with cytokines (TNF{alpha} and IFN{gamma}) in phenol red-free F12 medium for an additional 48 hours. NO synthesis was assessed by measuring the nitrite anion concentration, the reation product of NO, in the cell culture medium using Griess reagent. PTH and 1, 25[OH]{sub 2}D{sub 4} pretreatment induced a significant increase in NO production in the presence of TNF{alpha} and IFN{gamma}. PGE{sub 2} slightly induced NO production compared to the control group. But, PGE{sub 2} pretreatment did not affect in NO production in the presence of TNF{alpha} and IFN{gamma}. These results suggest that the actions of osteotropic hormones in bone metabolism may be partially mediated by NO in the presence of cytokines.

Ko, Seon Yil; Kim, Min Sung; Han, Won Jeong; Kim, Se Won; Kim, Jung Keun [Dankook University College of Medicine, Seoul (Korea, Republic of)

2005-09-15

223

Effects of osteotropic hormones on the nitric oxide production in culture of ROS17/2.8 cells  

International Nuclear Information System (INIS)

We performed the present study to investigate whether osteotropic hormones play roles on the nitric oxide (NO) production in culture of ROS17/2.8 osteoblastic cells. The osteoblastic cell line ROS17/2.8 cells were cultured in F12 medium supplemented with 5% fetal bovine serum (FBS) at 37.deg. C in a humidified atmosphere of 5% CO2 in air. ROS17/2.8 cells were plated in 96-well plants at a density of 2-3 x 103 cells/well and grown to confluence. Then the cells were pretreated with osteotropic hormones (parathyroid hormone (PTH) 20-500 ng/mL, 1, 25-dihydroxycholecalciferol (1, 25[OH]2D3) 1-100nM ; prostaglandin E2(PGE2) 20-500 ng/mL) in the medium supplemented with 0.4% FBS for (72 hours and the cells were treated with cytokines (TNF? and IFN?) in phenol red-free F12 medium for an additional 48 hours. NO synthesis was assessed by measuring the nitrite anion concentration, the reation product of NO, in the cell culture medium using Griess reagent. PTH and 1, 25[OH]2D4 pretreatment induced a significant increase in NO production in the presence of TNF? and IFN?. PGE2 slightly induced NO production compared to the control group. But, PGE2 pretreatment did not affect in NO production in the presence of TNF? and IFN?. These results suggest that the actions of osteotropic hormones in bone metabolism may be partially mediated by NO in the presence of cytokinesy NO in the presence of cytokines

224

Cell protective, ABC triblock polymer-based thermoresponsive hydrogels with ROS-triggered degradation and drug release.  

Science.gov (United States)

A combination of anionic and RAFT polymerization was used to synthesize an ABC triblock polymer poly[(propylenesulfide)-block-(N,N-dimethylacrylamide)-block-(N-isopropylacrylamide)] (PPS-b-PDMA-b-PNIPAAM) that forms physically cross-linked hydrogels when transitioned from ambient to physiologic temperature and that incorporates mechanisms for reactive oxygen species (ROS) triggered degradation and drug release. At ambient temperature (25 °C), PPS-b-PDMA-b-PNIPAAM assembled into 66 ± 32 nm micelles comprising a hydrophobic PPS core and PNIPAAM on the outer corona. Upon heating to physiologic temperature (37 °C), which exceeds the lower critical solution temperature (LCST) of PNIPAAM, micelle solutions (at ?2.5 wt %) sharply transitioned into stable, hydrated gels. Temperature-dependent rheology indicated that the equilibrium storage moduli (G') of hydrogels at 2.5, 5.0, and 7.5 wt % were 20, 380, and 850 Pa, respectively. The PPS-b-PDMA-b-PNIPAAM micelles were preloaded with the model drug Nile red, and the resulting hydrogels demonstrated ROS-dependent drug release. Likewise, exposure to the peroxynitrite generator SIN-1 degraded the mechanical properties of the hydrogels. The hydrogels were cytocompatible in vitro and were demonstrated to have utility for cell encapsulation and delivery. These hydrogels also possessed inherent cell-protective properties and reduced ROS-mediated cellular death in vitro. Subcutaneously injected PPS-b-PDMA-b-PNIPAAM polymer solutions formed stable hydrogels that sustained local release of the model drug Nile red for 14 days in vivo. These collective data demonstrate the potential use of PPS-b-PDMA-b-PNIPAAM as an injectable, cyto-protective hydrogel that overcomes conventional PNIPAAM hydrogel limitations such as syneresis, lack of degradability, and lack of inherent drug loading and environmentally responsive release mechanisms. PMID:25254509

Gupta, Mukesh K; Martin, John R; Werfel, Thomas A; Shen, Tianwei; Page, Jonathan M; Duvall, Craig L

2014-10-22

225

A novel synthetic analog of Militarin, MA-1 induces mitochondrial dependent apoptosis by ROS generation in human lung cancer cells.  

Science.gov (United States)

A synthetic Militarin analog-1[(2R,3R,4R,5R)-1,6-bis(4-(2,4,4-trimethylpentan-2-yl)phenoxy) hexane-2,3,4,5-tetraol] is a novel derivative of constituents from Cordyceps militaris, which has been used to treat a variety of chronic diseases including inflammation, diabetes, hyperglycemia and cancers. Here, we report for the first time the synthesis of Militarin analog-1 (MA-1) and the apoptotic mechanism of MA-1 against human lung cancer cell lines. Treatment with MA-1 significantly inhibited the viability of 3 human lung cancer cell lines. The inhibition of viability and growth in MA-1-treated A549 cells with an IC50 of 5?M were mediated through apoptosis induction, as demonstrated by an increase in DNA fragmentation, sub-G0/G1-DNA fraction, nuclear condensation, and phosphatidylserine exposure. The apoptotic cell death caused mitochondrial membrane permeabilization through regulation of expression of the Bcl-2 family proteins, leading to cytochrome c release in a time-dependent manner. Subsequently, the final stage of apoptosis, activation of caspase-9/-3 and cleavage of poly (ADP ribose) polymerase, was induced. Furthermore, A549 lung cancer cells were more responsive to MA-1 than a bronchial epithelial cell line (BEAS-2B), involving the rapid generation of reactive oxygen species (ROS), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) activation. The pharmacological inhibition of ROS generation and JNK/p38 MAPK exhibited attenuated DNA fragmentation in MA-1-induced apoptosis. Oral administration of MA-1 also retarded growth of A549 orthotopic xenografts. In conclusion, the present study indicates that the new synthetic derivative MA-1 triggers mitochondrial apoptosis through ROS generation and regulation of MAPKs and may be a potent therapeutic agent against human lung cancer. PMID:24161344

Yoon, Deok Hyo; Lim, Mi-Hee; Lee, Yu Ran; Sung, Gi-Ho; Lee, Tae-Ho; Jeon, Byeong Hwa; Cho, Jae Youl; Song, Won O; Park, Haeil; Choi, Sunga; Kim, Tae Woong

2013-12-15

226

Up-regulation of ROS by mitochondria-dependent bystander signaling contributes to genotoxicity of bystander effects  

International Nuclear Information System (INIS)

Genomic instability can be observed in bystander cells. However, the underlying mechanism(s) is still relatively unclear. In a previous study, we found that irradiated cells released mitochondria-dependent intracellular factor(s) which could lead to bystander ?-H2AX induction. In this paper, we used normal (?+) and mtDNA-depleted (?0) human-hamster hybrid cells to investigate mitochondrial effects on the genotoxicity in bystander effect through medium transfer experiments. Through the detection of DNA double-strand breaks with ?-H2AX, we found that the fraction of ?-H2AX positive cells changed with time when irradiation conditioned cell medium (ICCM) were harvested. ICCM harvested from irradiated ?+ cells at 10 min post-irradiation (?+ ICCM10min) caused larger increases of bystander ?-H2AX induction comparing to ?0 ICCM10min, which only caused a slight increase of bystander ?-H2AX induction. The ?+ ICCM10min could also result in the up-regulation of ROS production (increased by 35% at 10 min), while there was no significant increase in cells treated with ?0 ICCM10min. We treated cells with dimethyl sulfoxide (DMSO), the scavenger of ROS, and quenched ?-H2AX induction by ?+ ICCM. Furthermore, after the medium had been transferred and the cells were continuously cultured for 7 days, we found significantly increased CD59-- gene loci mutation (increased by 45.9%) and delayed cell death in the progeny of ?+ ICCM-treated bystander cells. In conclusion, the work presented here suggested that up-regulation of the mitochondria-dependent ROS might be very important in mediating genotoxicity of bystander effects.

227

Up-regulation of ROS by mitochondria-dependent bystander signaling contributes to genotoxicity of bystander effects  

Energy Technology Data Exchange (ETDEWEB)

Genomic instability can be observed in bystander cells. However, the underlying mechanism(s) is still relatively unclear. In a previous study, we found that irradiated cells released mitochondria-dependent intracellular factor(s) which could lead to bystander {gamma}-H2AX induction. In this paper, we used normal ({rho}{sup +}) and mtDNA-depleted ({rho}{sup 0}) human-hamster hybrid cells to investigate mitochondrial effects on the genotoxicity in bystander effect through medium transfer experiments. Through the detection of DNA double-strand breaks with {gamma}-H2AX, we found that the fraction of {gamma}-H2AX positive cells changed with time when irradiation conditioned cell medium (ICCM) were harvested. ICCM harvested from irradiated {rho}{sup +} cells at 10 min post-irradiation ({rho}{sup +} ICCM{sub 10min}) caused larger increases of bystander {gamma}-H2AX induction comparing to {rho}{sup 0} ICCM{sub 10min}, which only caused a slight increase of bystander {gamma}-H2AX induction. The {rho}{sup +} ICCM{sub 10min} could also result in the up-regulation of ROS production (increased by 35% at 10 min), while there was no significant increase in cells treated with {rho}{sup 0} ICCM{sub 10min}. We treated cells with dimethyl sulfoxide (DMSO), the scavenger of ROS, and quenched {gamma}-H2AX induction by {rho}{sup +} ICCM. Furthermore, after the medium had been transferred and the cells were continuously cultured for 7 days, we found significantly increased CD59{sup -} gene loci mutation (increased by 45.9%) and delayed cell death in the progeny of {rho}{sup +} ICCM-treated bystander cells. In conclusion, the work presented here suggested that up-regulation of the mitochondria-dependent ROS might be very important in mediating genotoxicity of bystander effects.

Chen Shaopeng [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Zhao Ye; Zhao Guoping [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Han Wei [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Bao Lingzhi [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Yu, K.N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Wu Lijun, E-mail: ljw@ipp.ac.cn [Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2009-06-18

228

Moderate extracellular acidification inhibits capsaicin-induced cell death through regulating calcium mobilization, NF-?B translocation and ROS production in synoviocytes  

International Nuclear Information System (INIS)

Highlights: ? Moderate extracellular acidification regulates intracellular Ca2+ mobilization. ? Moderate acidification activates NF-?B nuclear translocation in synoviocytes. ? Moderate acidification depresses the ROS production induced by capsaicin. ? Moderate acidification inhibits capsaicin-caused synoviocyte death. -- Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca2+ entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca2+ entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca2+ release from intracellular stores. The nuclear translocation of NF-?B was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-?B. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca2+ mobilization, activating NF-?B nuclear translocation and depressing ROS production.

229

Moderate extracellular acidification inhibits capsaicin-induced cell death through regulating calcium mobilization, NF-{kappa}B translocation and ROS production in synoviocytes  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Moderate extracellular acidification regulates intracellular Ca{sup 2+} mobilization. Black-Right-Pointing-Pointer Moderate acidification activates NF-{kappa}B nuclear translocation in synoviocytes. Black-Right-Pointing-Pointer Moderate acidification depresses the ROS production induced by capsaicin. Black-Right-Pointing-Pointer Moderate acidification inhibits capsaicin-caused synoviocyte death. -- Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca{sup 2+} entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca{sup 2+} entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca{sup 2+} release from intracellular stores. The nuclear translocation of NF-{kappa}B was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-{kappa}B. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca{sup 2+} mobilization, activating NF-{kappa}B nuclear translocation and depressing ROS production.

Hu, Fen; Yang, Shuang; Zhao, Dan; Zhu, Shuyan; Wang, Yuxiang [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China); Li, Junying, E-mail: jyli04@nankai.edu.cn [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China)

2012-07-20

230

Cigarette smoke extract upregulates heme oxygenase-1 via PKC/NADPH oxidase/ROS/PDGFR/PI3K/Akt pathway in mouse brain endothelial cells  

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Full Text Available Abstract Background In the brain, the inducible form of heme oxygenase (HO-1 has been recently demonstrated to exacerbate early brain injury produced by intracerebral hemorrhagic stroke which incident rate has been correlated with cigarette smoking previously. Interestingly, cigarette smoke (CS or chemicals present in CS have been shown to induce HO-1 expression in various cell types, including cerebral endothelial cells. However, the mechanisms underlying CS modulating HO-1 protein expression are not completely understood in the brain vessels. Objective The aim of the present study was to investigate the mechanisms underlying CS modulating HO-1 protein expression in cerebral endothelial cells. Methods Cultured cerebral endothelial cells (bEnd.3 were used to investigate whether a particulate phase of cigarette smoke extract (PPCSE regulates HO-1 expression and to investigate the molecular mechanisms involved in HO-1 expression in bEnd.3 cells. Results We demonstrated that PPCSE (30 ?g/ml significantly induced HO-1 protein expression and its enzymatic activity in bEnd.3 cells determined by western blotting and bilirubin formation, respectively. PPCSE-induced HO-1 expression was mediated through phosphatidylcholine phospholipase C (PC-PLC, PKC?, and PI3K/Akt which were observed by pretreatment with their respective pharmacological inhibitors or transfection with dominant negative mutants of PKC? and Akt. ROS scavenger (N-acetyl-L-cysteine, NAC blocked the PPCSE-induced ROS generation and HO-1 expression. Pretreatment with selective inhibitors of PKC? (rottlerin and NADPH oxidase [diphenyleneiodonium chloride (DPI and apocynin (APO] attenuated the PPCSE-induced NADPH oxidase activity, ROS generation, and HO-1 expression. In addition, we found that PPCSE induced PI3K/Akt activation via NADPH oxidase/ROS-dependent PDGFR phosphorylation. Conclusions Taken together, these results suggested that PPCSE-induced HO-1 expression is mediated by a PC-PLC/PKC?/NADPH oxidase-dependent PDGFR/PI3K/Akt pathway in bEnd.3 cells.

Kou Yu

2011-08-01

231

Mitochondrial metabolism and ROS generation are essential for Kras-mediated tumorigenicity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Otto Warburg's theory on the origins of cancer postulates that tumor cells have defects in mitochondrial oxidative phosphorylation and therefore rely on high levels of aerobic glycolysis as the major source of ATP to fuel cellular proliferation (the Warburg effect). This is in contrast to normal cells, which primarily utilize oxidative phosphorylation for growth and survival. Here we report that the major function of glucose metabolism for Kras-induced anchorage-independent growth, a hallmark...

Weinberg, Frank; Hamanaka, Robert; Wheaton, William W.; Weinberg, Samuel; Joseph, Joy; Lopez, Marcos; Kalyanaraman, Balaraman; Mutlu, Go?khan M.; Budinger, G. R. Scott; Chandel, Navdeep S.

2010-01-01

232

ROS and Sympathetically Mediated Mitochondria Activation in Brown Adipose Tissue Contribute to Methamphetamine-Induced Hyperthermia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Methamphetamine (Meth) abuse has been shown to induce alterations in mitochondrial function in the brain as well as to induce hyperthermia, which contributes to neurotoxicity and Meth-associated mortality. Brown adipose tissue (BAT), a thermogenic site known to be important in neonates, has recently regained importance since being identified in significant amounts and in correlation with metabolic balance in human adults. Given the high mitochondrial content of BAT and its role in thermogenes...

Maria CeciliaGMarcondes; ManuelSanchez-Alavez; HowardSFox

2013-01-01

233

Antifungal activity of ZnO nanoparticles-the role of ROS mediated cell injury  

International Nuclear Information System (INIS)

Metal oxide nanoparticles have marked antibacterial activity. The toxic effect of these nanoparticles, such as those comprised of ZnO, has been found to occur due to an interaction of the nanoparticle surface with water, and to increase with a decrease in particle size. In the present study, we tested the ability of ZnO nanoparticles to affect the viability of the pathogenic yeast, Candida albicans (C. albicans). A concentration-dependent effect of ZnO on the viability of C. albicans was observed. The minimal fungicidal concentration of ZnO was found to be 0.1 mg ml-1 ZnO; this concentration caused an inhibition of over 95% in the growth of C. albicans. ZnO nanoparticles also inhibited the growth of C. albicans when it was added at the logarithmic phase of growth. Addition of histidine (a quencher of hydroxyl radicals and singlet oxygen) caused reduction in the effect of ZnO on C. albicans depending on its concentration. An almost complete elimination of the antimycotic effect was achieved following addition of 5 mM of histidine. Exciting the ZnO by visible light increased the yeast cell death. The effects of histidine suggest the involvement of reactive oxygen species, including hydroxyl radicals and singlet oxygen, in cell death. In light of the above results it appears that metal oxide nanoparticles may provide a novel family of fungicidal compounds.

234

Antifungal activity of ZnO nanoparticles-the role of ROS mediated cell injury  

Energy Technology Data Exchange (ETDEWEB)

Metal oxide nanoparticles have marked antibacterial activity. The toxic effect of these nanoparticles, such as those comprised of ZnO, has been found to occur due to an interaction of the nanoparticle surface with water, and to increase with a decrease in particle size. In the present study, we tested the ability of ZnO nanoparticles to affect the viability of the pathogenic yeast, Candida albicans (C. albicans). A concentration-dependent effect of ZnO on the viability of C. albicans was observed. The minimal fungicidal concentration of ZnO was found to be 0.1 mg ml{sup -1} ZnO; this concentration caused an inhibition of over 95% in the growth of C. albicans. ZnO nanoparticles also inhibited the growth of C. albicans when it was added at the logarithmic phase of growth. Addition of histidine (a quencher of hydroxyl radicals and singlet oxygen) caused reduction in the effect of ZnO on C. albicans depending on its concentration. An almost complete elimination of the antimycotic effect was achieved following addition of 5 mM of histidine. Exciting the ZnO by visible light increased the yeast cell death. The effects of histidine suggest the involvement of reactive oxygen species, including hydroxyl radicals and singlet oxygen, in cell death. In light of the above results it appears that metal oxide nanoparticles may provide a novel family of fungicidal compounds.

Lipovsky, Anat; Gedanken, Aharon [Department of Chemistry, Kanbar Laboratory for Nanomaterials, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900 (Israel); Nitzan, Yeshayahu [Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900 (Israel); Lubart, Rachel [Department of Chemistry, Bar-Ilan University, Ramat-Gan (Israel)

2011-03-11

235

The Protective Role of Antioxidants in the Defence against ROS/RNS-Mediated Environmental Pollution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Overproduction of reactive oxygen and nitrogen species can result from exposure to environmental pollutants, such as ionising and nonionising radiation, ultraviolet radiation, elevated concentrations of ozone, nitrogen oxides, sulphur dioxide, cigarette smoke, asbestos, particulate matter, pesticides, dioxins and furans, polycyclic aromatic hydrocarbons, and many other compounds present in the environment. It appears that increased oxidative/nitrosative stress is often neglected mechanism by ...

Ak, Borut Polj X.; Rok Fink

2014-01-01

236

ROS-mediated genotoxicity of asbestos-cement in mammalian lung cells in vitro  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Asbestos is a known carcinogen and co-carcinogen. It is a persisting risk in our daily life due to its use in building material as asbestos-cement powder. The present study done on V79-cells (Chinese hamster lung cells demonstrates the cytotoxic and genotoxic potential of asbestos-cement powder (ACP in comparison with chrysotile asbestos. A co-exposure of chrysotile and ACP was tested using the cell viability test and the micronucleus assay. The kinetochore analysis had been used to analyse the pathway causing such genotoxic effects. Thiobarbituric acid-reactive substances were determined as evidence for the production of reactive oxygen species. Both, asbestos cement as well as chrysotile formed micronuclei and induced loss of cell viability in a concentration- and time- dependent way. Results of TBARS analysis and iron chelator experiments showed induction of free radicals in ACP- and chrysotile exposed cultures. CaSO4 appeared to be a negligible entity in enhancing the toxic potential of ACP. The co-exposure of both, ACP and chrysotile, showed an additive effect in enhancing the toxicity. The overall study suggests that asbestos-cement is cytotoxic as well as genotoxic in vitro. In comparison to chrysotile the magnitude of the toxicity was less, but co-exposure increased the toxicity of both.

Rödelsperger Klaus

2005-10-01

237

ROS-mediated upregulation of Noxa overcomes chemoresistance in chronic lymphocytic leukemia  

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In recent years considerable progress has been made in treatment strategies for chronic lymphocytic leukemia (CLL). However, the disease remains incurable because of the development of chemoresistance. Strategies to overcome resistance mechanisms are therefore highly needed. At least two mechanisms contribute to the development of resistance to drugs; acquired mutations resulting in a dysfunctional p53 response and shifts in the balance between apoptosis-regulating proteins. Platinum-based co...

Tonino, Sh; Laar, J.; Oers, Mh; Wang, Jy; Eldering, E.; Kater, Ap

2010-01-01

238

Induction of Apoptosis and Antiproliferative Activity of Naringenin in Human Epidermoid Carcinoma Cell through ROS Generation and Cell Cycle Arrest  

Science.gov (United States)

A natural predominant flavanone naringenin, especially abundant in citrus fruits, has a wide range of pharmacological activities. The search for antiproliferative agents that reduce skin carcinoma is a task of great importance. The objective of this study was to analyze the anti-proliferative and apoptotic mechanism of naringenin using MTT assay, DNA fragmentation, nuclear condensation, change in mitochondrial membrane potential, cell cycle kinetics and caspase-3 as biomarkers and to investigate the ability to induce reactive oxygen species (ROS) initiating apoptotic cascade in human epidermoid carcinoma A431 cells. Results showed that naringenin exposure significantly reduced the cell viability of A431 cells (pnaringenin. It also caused naringenin-mediated epidermoid carcinoma apoptosis by inducing mitochondrial depolarization. Cell cycle study showed that naringenin induced cell cycle arrest in G0/G1 phase of cell cycle and caspase-3 analysis revealed a dose dependent increment in caspase-3 activity which led to cell apoptosis. This study confirms the efficacy of naringenin that lead to cell death in epidermoid carcinoma cells via inducing ROS generation, mitochondrial depolarization, nuclear condensation, DNA fragmentation, cell cycle arrest in G0/G1 phase and caspase-3 activation. PMID:25330158

Jafri, Asif; Ahmad, Sheeba; Afzal, Mohammad; Arshad, Md

2014-01-01

239

Mechanistic Investigation of ROS-Induced DNA Damage by Oestrogenic Compounds in Lymphocytes and Sperm Using the Comet Assay  

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Full Text Available Past research has demonstrated that oestrogenic compounds produce strand breaks in the DNA of sperm and lymphocytes via reactive oxygen species (ROS. In the current investigation, sperm and lymphocytes were treated in vitro with oestrogenic compounds (diethylstilboestrol, progesterone, 17?-oestradiol, noradrenaline and triiodotyronine and several aspects of DNA damage were investigated. Firstly, mediation of DNA damage by lipid peroxidation was investigated in the presence of BHA (a lipid peroxidation blocker. BHA reduced the DNA damage generated by 17?-oestradiol and diethylstilboestrol in a statistically significant manner. No effects were observed for sperm. Secondly, the presence of oxidized bases employing FPG and EndoIII were detected for lymphocytes and sperm in the negative control and after 24 h recovery in lymphocytes but not immediately after treatment for both cell types. The successful detection of oxidized bases in the negative control (untreated of sperm provides an opportunity for its application in biomonitoring studies. DNA repair at 24 h after exposure was also studied. A nearly complete recovery to negative control levels was shown in lymphocytes 24 h recovery after oestrogenic exposure and this was statistically significant in all cases. Rapid rejoining of DNA, in a matter of hours, is a characteristic of DNA damaged by ROS.

Diana Anderson

2011-04-01

240

Mannan induces ROS-regulated, IL-17A-dependent psoriasis arthritis-like disease in mice.  

Science.gov (United States)

Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by unknown environmental factors, affecting skin and articular joints. A single i.p. exposure to mannan from Saccharomyces cerevisiae induced an acute inflammation in inbred mouse strains resembling human Ps and PsA-like disease, whereas multiple injections induced a relapsing disease. Exacerbation of disease severity was observed in mice deficient for generation of reactive oxygen species (ROS). Interestingly, restoration of ROS production, specifically in macrophages, ameliorated both skin and joint disease. Neutralization of IL-17A, mainly produced by ?? T cells, completely blocked disease symptoms. Furthermore, mice depleted of granulocytes were resistant to disease development. In contrast, certain acute inflammatory mediators (C5, Fc? receptor III, mast cells, and histamine) and adaptive immune players (?? T and B cells) were redundant in disease induction. Hence, we propose that mannan-induced activation of macrophages leads to TNF-? secretion and stimulation of local ?? T cells secreting IL-17A. The combined action of activated macrophages and IL-17A produced in situ drives neutrophil infiltration in the epidermis and dermis of the skin, leading to disease manifestations. Thus, our finding suggests a new mechanism triggered by exposure to exogenous microbial components, such as mannan, that can induce and exacerbate Ps and PsA. PMID:25136095

Khmaladze, Ia; Kelkka, Tiina; Guerard, Simon; Wing, Kajsa; Pizzolla, Angela; Saxena, Amit; Lundqvist, Katarina; Holmdahl, Meirav; Nandakumar, Kutty Selva; Holmdahl, Rikard

2014-09-01

 
 
 
 
241

TGF-?1 increases invasiveness of SW1990 cells through Rac1/ROS/NF-?B/IL-6/MMP-2  

International Nuclear Information System (INIS)

Research highlights: ? Rac1 mediates TGF-?1-induced SW1990 invasion through MMP-2 secretion and activation. ? NADPH-generated ROS act downstream of Rac1 in TGF-?1-challenged SW1990 cells. ? TGF-?1-stimulated ROS activate NF-?B in SW1990 cells. ? NF?B-induced IL-6 release is required for secretion and activation of MMP-2 in SW1990 cells. -- Abstract: Human pancreatic cancer invasion and metastasis have been found to correlate with increased levels of active matrix metalloproteinase 2 (MMP-2). The multifunctional cytokine transforming growth factor beta 1 (TGF-?1) has been shown to increase both secretion of MMP-2 and invasion by several pancreatic cancer cell types. In the present study, we investigated the signaling pathway involved in TGF-?1-promoted MMP-2 secretion and invasion by human pancreatic cancer cells SW1990. Using specific inhibitors, we found that stimulation of these tumor cells with TGF-?1 induced secretion and activation of the collagenase MMP-2, which was required for TGF-?1-stimulated invasion. Our results also indicate that signaling events involved in TGF-?1-enhanced SW1990 invasiveness comprehend activation of Rac1 followed by generation of reactive oxygen species through nicotinamide adenine dinucleotide phosphate-oxidase, activation of nuclear factor-kappa beta, release of interleukin-6, and secretion and activation of MMP-2.

242

Production of ROS and its effects on mitochondrial and nuclear DNA, human spermatozoa, and sperm function  

Directory of Open Access Journals (Sweden)

Full Text Available Over the past few decades many researchers studying the causes of male infertility have recently focused on the role played by reactive oxygen species (ROS – highly reactive oxidizing agents belonging to the class of free radicals. If ROS levels rise, oxidative stress (OS occurs, which results in oxygen and oxygen derived oxidants, and in turn increases the rates of cellular damage. In human, ROS are produced by a variety of semen components, and antioxidants in the seminal fluid keep their level balance. Small amounts of ROS help spermatozoa acquire their necessary fertilizing capabilities. Many researches showed that ROS attack DNA integrity in the sperm nucleus by causing base modification, DNA strand breaks, and chromatin cross linking. The DNA damage induced excessive levels of ROS and might accelerate the process of germ cell apoptosis leading to a decline in sperm counts associated with male infertility. This paper will review the molecular (cellular origins of ROS in human semen, how ROS damage sperm nuclear DNA, and how such DNA damage contributes to male infertility. Increased ROS production by spermatozoa is associated with a decreased mitochondrial membrane potential (MMP, which is an important indicator of functional integrity of the spermatozoa. Germ cell apoptosis is essential for normal spermatogenesis and its dysregulation may lead to male infertility. Thus, understanding the causes and mechanisms of germ cell apoptosis is of major importance in preventing male reproductive problems. Levels of apoptosis in mature spermatozoa that were significantly correlated with levels of seminal ROS determined by chemiluminescence assay indicate the linkage between ROS and male fertility problems. (Med J Indones 2007; 16:127-33 Keywords: Apoptosis, infertility, free radicals

Hardi Darmawan

2007-05-01

243

ROS inhibitor N-acetyl-l-cysteine antagonizes the activity of proteasome inhibitors  

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NAC (N-acetyl-l-cysteine) is commonly used to identify and test ROS (reactive oxygen species) inducers, and to inhibit ROS. In the present study, we identified inhibition of proteasome inhibitors as a novel activity of NAC. Both NAC and catalase, another known scavenger of ROS, similarly inhibited ROS levels and apoptosis associated with H2O2. However, only NAC, and not catalase or another ROS scavenger Trolox, was able to prevent effects linked to proteasome inhibition, such as protein stabilization, apoptosis and accumulation of ubiquitin conjugates. These observations suggest that NAC has a dual activity as an inhibitor of ROS and proteasome inhibitors. Recently, NAC was used as a ROS inhibitor to functionally characterize a novel anticancer compound, piperlongumine, leading to its description as a ROS inducer. In contrast, our own experiments showed that this compound depicts features of proteasome inhibitors including suppression of FOXM1 (Forkhead box protein M1), stabilization of cellular proteins, induction of ROS-independent apoptosis and enhanced accumulation of ubiquitin conjugates. In addition, NAC, but not catalase or Trolox, interfered with the activity of piperlongumine, further supporting that piperlongumine is a proteasome inhibitor. Most importantly, we showed that NAC, but not other ROS scavengers, directly binds to proteasome inhibitors. To our knowledge, NAC is the first known compound that directly interacts with and antagonizes the activity of proteasome inhibitors. Taken together, the findings of the present study suggest that, as a result of the dual nature of NAC, data interpretation might not be straightforward when NAC is utilized as an antioxidant to demonstrate ROS involvement in drug-induced apoptosis. PMID:23772801

Halasi, Marianna; Wang, Ming; Chavan, Tanmay S.; Gaponenko, Vadim; Hay, Nissim; Gartel, Andrei L.

2015-01-01

244

NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-?-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells.  

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TNF-? plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-? in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-?-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-? induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-?-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-l-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-?B (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47(phox), p42, p38, JNK1, p65, or PYK2. Moreover, TNF-? markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-?-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-?B (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-?-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-?-stimulated MAPKs and NF-?B activation. Thus, in H9c2 cells, we are the first to show that TNF-?-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-?B cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-?-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-? on H9c2 cells may provide potential therapeutic targets of chronic heart failure. PMID:23774252

Yang, Chuen-Mao; Lee, I-Ta; Hsu, Ru-Chun; Chi, Pei-Ling; Hsiao, Li-Der

2013-10-15

245

ROS evaluation for a series of CNTs and their derivatives using an ESR method with DMPO  

International Nuclear Information System (INIS)

Carbon nanotubes (CNTs) are important materials in advanced industries. It is a concern that pulmonary exposure to CNTs may induce carcinogenic responses. It has been recently reported that CNTs scavenge ROS though non-carbon fibers generate ROS. A comprehensive evaluation of ROS scavenging using various kinds of CNTs has not been demonstrated well. The present work specifically investigates ROS scavenging capabilities with a series of CNTs and their derivatives that were physically treated, and with the number of commercially available CNTs. CNT concentrations were controlled at 0.2 through 0.6 wt%. The ROS scavenging rate was measured by ESR with DMPO. Interestingly, the ROS scavenging rate was not only influenced by physical treatments, but was also dependent on individual manufacturing methods. Ratio of CNTs to DMPO/ hydrogen peroxide is a key parameter to obtain appropriate ROS quenching results for comparison of CNTs. The present results suggest that dangling bonds are not a sole factor for scavenging, and electron transfer on the CNT surface is not clearly determined to be the sole mechanism to explain ROS scavenging.

246

Screening for the FIG-ROS1 fusion in biliary tract carcinomas by nested PCR.  

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ROS1 rearrangements have been detected in a variety of tumors and are considered as suitable targets of anticancer therapies. We developed a new, quick, specific, and sensitive PCR test to screen for the FIG-ROS1 fusion and applied it to a series of Italian patients with bile duct carcinoma (BTC). Formalin-fixed, paraffin-embedded tissues, derived from 65 Italian BTC patients, and six cell lines were analyzed by nested PCR to investigate the prevalence of a previously reported FIG-ROS1 fusion. The specificity and sensitivity of nested PCR were investigated in FIG-ROS1 positive U118MG cells in reconstitution experiments with peripheral blood mononuclear cells. We found that six out of 65 (9%) BTC patients were positive for the FIG-ROS1 fusion, comprising two out of 14 (14%) gallbladder carcinoma (GBC) patients and four out of 25 (16%) extrahepatic cholangiocarcinoma (ECC) patients. None of the 26 intrahepatic cholangiocarcinoma cases harbored the FIG-ROS1 fusion. All the cell lines were negative for this variant. In conclusion, 14-16% of GBC and ECC were positive for FIG-ROS1. This may have clinical implications, since these patients will potentially benefit from the treatment with specific ROS1 inhibitors. PMID:25231053

Peraldo Neia, Caterina; Cavalloni, Giuliana; Balsamo, Antonella; Venesio, Tiziana; Napoli, Francesca; Sassi, Francesco; Martin, Vittoria; Frattini, Milo; Aglietta, Massimo; Leone, Francesco

2014-12-01

247

Reactive oxygen species (ROS) is not a promotor of taxol-induced cytoplasmic vacuolization  

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we have previously reported that taxol, a potent anticancer agent, induces caspase-independent cell death and cytoplasmic vacuolization in human lung adenocarcinoma (ASTC-a-1) cells. However, the mechanisms of taxol-induced cytoplasmic vacuolization are poorly understood. Reactive oxygen species (ROS) has been reported to be involved in the taxol-induced cell death. Here, we employed confocal fluorescence microscopy imaging to explore the role of ROS in taxol-induced cytoplasmic vacuolization. We found that ROS inhibition by addition of N-acetycysteine (NAC), a total ROS scavenger, did not suppress these vacuolization but instead increased vacuolization. Take together, our results showed that ROS is not a promotor of the taxol-induced cytoplasmic vacuolization.

Sun, Qingrui; Chen, Tongsheng

2009-02-01

248

TiO2 nanoparticle-induced ROS correlates with modulated immune cell function  

International Nuclear Information System (INIS)

Design of non-toxic nanoparticles will be greatly facilitated by understanding the nanoparticle-cell interaction mechanism on a cell function level. Mast cells are important cells for the immune system’s first line of defense, and we can utilize their exocytotic behavior as a model cellular function as it is a conserved process across cell types and species. Perturbations in exocytosis can also have implications for whole organism health. One proposed mode of toxicity is nanoparticle-induced reactive oxygen species (ROS), particularly for titanium dioxide (TiO2) nanoparticles. Herein, we have correlated changes in ROS with the perturbation of the critical cell function of exocytosis, using UV light to induce greater levels of ROS in TiO2 exposed cells. The primary culture mouse peritoneal mast cells (MPMCs) were exposed to varying concentrations of TiO2 nanoparticles for 24 h. ROS content was determined using 2,7-dihydrodichlorofluorescein diacetate (DCFDA). Cellular viability was determined with the MTT and Trypan blue assays, and exocytosis was measured by the analytical electrochemistry technique of carbon-fiber microelectrode amperometry. MPMCs exposed to TiO2 nanoparticles experienced a dose-dependent increase in total ROS content. While there was minimal impact of ROS on cellular viability, there is a correlation between ROS amount and exocytosis perturbation. As nanoparticle-induced ROS increases, there is a signifinduced ROS increases, there is a significant decrease (45 %) in the number of serotonin molecules being released during exocytosis, increase (26 %) in the amount of time for each exocytotic granule to release, and decrease (28 %) in the efficiency of granule trafficking and docking. This is the first evidence that nanoparticle-induced ROS correlates with chemical messenger molecule secretion, possibly making a critical connection between functional impairment and mechanisms contributing to that impairment.

249

Temporal dynamics of ROS biogenesis under simulated solar radiation in the cyanobacterium Anabaena variabilis PCC 7937.  

Science.gov (United States)

We studied the temporal generation of reactive oxygen species (ROS) in the cyanobacterium Anabaena variabilis PCC 7937 under simulated solar radiation using WG 280, WG 295, WG 305, WG 320, WG 335, WG 345, and GG 400 nm cut-off filters to find out the minimum exposure time and most effective region of the solar spectrum inducing highest level of ROS. There was no significant generation of ROS in all treatments in comparison to the samples kept in the dark during the first 8 h of exposure; however, after 12 h of exposure, ROS were significantly generated in samples covered with 305, 295, or 280 nm cut-off filters. In contrast with ROS, the fragmentation of filaments was predominantly seen in 280 nm cut-off filter covered samples after 12 h of exposure. After 24 h of exposure, ROS levels were significantly higher in all samples than in the dark; however, the ROS signals were more pronounced in 320, 305, 295, or 280 nm cut-off filter covered samples. In contrast, the length of filaments was reduced in 305, 295, or 280 nm cut-off filter covered samples after 24 h of exposure. Thus, fragmentation of the filament was induced by all wavelengths of the UV-B region contrary to the UV-A region where only shorter wavelengths were able to induce the fragmentation. In contrast, ROS were generated by all wavelengths of the solar spectrum after 24 h of exposure; however, shorter wavelengths of both the UV-A and the UV-B regions were more effective in generating ROS in comparison to their higher wavelengths and photosynthetic active radiation (PAR). Moreover, lower wavelengths of UV-B were more efficient than the lower wavelengths of the UV-A radiation. Findings from this study suggest that certain threshold levels of ROS are required to induce the fragmentation of filaments. PMID:24633292

Singh, Shailendra P; Rastogi, Rajesh P; Häder, Donat-P; Sinha, Rajeshwar P

2014-09-01

250

ROS production in brown adipose tissue mitochondria: The question of UCP1-dependence.  

Science.gov (United States)

Whether active UCP1 can reduce ROS production in brown-fat mitochondria is presently not settled. The issue is of principal significance, as it can be seen as a proof- or disproof-of-principle concerning the ability of any protein to diminish ROS production through membrane depolarization. We therefore undertook a comprehensive investigation of the significance of UCP1 for ROS production, by comparing the ROS production in brown-fat mitochondria isolated from wildtype mice (that display membrane depolarization) or from UCP1(-/-) mice (with a high membrane potential). We tested the significance of UCP1 for glycerol-3-phosphate-supported ROS production by three methods (fluorescent dihydroethidium and the ESR probe PHH for superoxide, and fluorescent Amplex Red for hydrogen peroxide), and followed ROS production also with succinate, acyl-CoA or pyruvate as substrate. We studied the effects of the reverse electron flow inhibitor rotenone, the UCP1 activity inhibitor GDP, and the uncoupler FCCP. We also examined the effect of a physiologically induced increase in UCP1 amount. We noted GDP effects that were not UCP1-related. We conclude that only ROS production supported by exogenously added succinate was affected by the presence of active UCP1; ROS production supported by any other tested substrate (including endogenously generated succinate) was unaffected. This conclusion indicates that UCP1 is not involved in control of ROS production in brown-fat mitochondria. Extrapolation of these data to other tissues would imply that membrane depolarization may not necessarily decrease physiologically relevant ROS production. This article is a part of a Special Issue entitled: 18th European Bioenergetics Conference (Biochim. Biophys. Acta, Volume 1837, Issue 7, July 2014). PMID:24769119

Shabalina, Irina G; Vrbacký, Marek; Pecinová, Alena; Kalinovich, Anastasia V; Drahota, Zden?k; Houšt?k, Josef; Mrá?ek, Tomáš; Cannon, Barbara; Nedergaard, Jan

2014-12-01

251

Role of mitochondria ROS generation in ethanol-induced NLRP3 inflammasome activation and cell death in astroglial cells  

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Full Text Available Toll-like receptors (TLRs and Nod-like receptors (NLRs are innate immunity sensors that provide an early/effective response to pathogenic or injury conditions. We have reported that ethanol-induced TLR4 activation triggers signaling inflammatory responses in glial cells, causing neuroinflammation and brain damage. However, it is uncertain if ethanol is able to activate NLRs /inflammasome in astroglial cells, which is the mechanism of activation, and whether there is crosstalk between both immune sensors in glial cells. Here we show that chronic ethanol treatment increases the co-localization of caspase-1 with GFAP+ cells, and up-regulates IL-1? and IL-18 in the frontal medial cortex in WT, but not in TLR4 knock-out mice. We further show that cultured cortical astrocytes expressed several inflammasomes (NLRP3, AIM2, NLRP1 and IPAF, although NLRP3 mRNA is the predominant form. Ethanol, as ATP and LPS treatments, up-regulates NLRP3 expression, and causes caspase-1 cleavage and the release of IL-1? and IL-18 in astrocytes supernatant. Ethanol-induced NLRP3/caspase-1 activation is mediated by mitochondrial (m ROS generation because when using a specific mitochondria ROS scavenger, the mito-TEMPO (500 ?M or NLRP3 blocking peptide (4?g/ml or a specific caspase-1 inhibitor, Z-YVAD-FMK (10 ?M, abrogates mROS release and reduces the up-regulation of IL-1? and IL-18 induced by ethanol or LPS or ATP. Confocal microscopy studies further confirm that ethanol, ATP or LPS promotes NLRP3/caspase-1 complex recruitment within the mitochondria to promote cell death by caspase-1-mediated pyroptosis, which accounts for ? 73 % of total cell death (?22% and the remaining (?25% die by caspase-3-dependent apoptosis. Suppression of the TLR4 function abrogates most ethanol effects on NLRP3 activation and reduces cell death. These findings suggest that NLRP3 participates, in ethanol-induced neuroinflammation and highlight the NLRP3/TLR4 crosstalk in ethanol-induced brain injury.

Consuelo GUERRI

2014-08-01

252

Different experimental approaches in modelling cataractogenesis: An overview of selenite-induced nuclear cataract in rats  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cataract, the opacification of eye lens, is the leading cause of blindness worldwide. At present, the only remedy is surgical removal of the cataractous lens and substitution with a lens made of synthetic polymers. However, besides significant costs of operation and possible complications, an artificial lens just does not have the overall optical qualities of a normal one. Hence it remains a significant public health problem, and biochemical solutions or pharmacological interventions that wil...

Kyselova, Zuzana

2010-01-01

253

Astaxanthin inhibits apoptosis in alveolar epithelial cells type II in vivo and in vitro through the ROS-dependent mitochondrial signalling pathway.  

Science.gov (United States)

Oxidative stress is an important molecular mechanism underlying lung fibrosis. The mitochondrion is a major organelle for oxidative stress in cells. Therefore, blocking the mitochondrial signalling pathway may be the best therapeutic manoeuver to ameliorate lung fibrosis. Astaxanthin (AST) is an excellent antioxidant, but no study has addressed the pathway of AST against pulmonary oxidative stress and free radicals by the mitochondrion-mediated signalling pathway. In this study, we investigated the antioxidative effects of AST against H2 O2 - or bleomycin (BLM)-induced mitochondrial dysfunction and reactive oxygen species (ROS) production in alveolar epithelial cells type II (AECs-II) in vivo and in vitro. Our data show that AST blocks H2 O2 - or BLM-induced ROS generation and dose-dependent apoptosis in AECs-II, as characterized by changes in cell and mitochondria morphology, translocation of apoptotic proteins, inhibition of cytochrome c (Cyt c) release, and the activation of caspase-9, caspase-3, Nrf-2 and other cytoprotective genes. These data suggest that AST inhibits apoptosis in AECs-II cells through the ROS-dependent mitochondrial signalling pathway and may be of potential therapeutic value in lung fibrosis treatment. PMID:25215580

Song, Xiaodong; Wang, Bingsi; Lin, Shengcui; Jing, Lili; Mao, Cuiping; Xu, Pan; Lv, Changjun; Liu, Wen; Zuo, Ji

2014-11-01

254

ROS2: a multichannel vision for the robotic REM telescope  

Science.gov (United States)

During 2013, a new visible camera has been finally installed and tested at the 60cm, robotic REM telescope in the la Silla Observatory. REM is an Italian, fast-reacting telescope initially designed and built for the immediate response to GRB automatic alerts, but since the first light in 2003 its usage has been covering a wider range of astronomical interests. While the IR camera REMIR was reaching the expected limiting magnitudes, the original ROSS visible camera suffered, since the beginning, of a rather poor performance. We set therefore to implement a newer optical camera, leading to the design, tests and integration of ROS2, a dichroic-based four channels imaging camera. The four Sloan-like pass bands are imaged, at the same time, in four quadrants of the CCD, an Andor multilevel Peltier detector. The tests during the science commissioning show an impressive improvement in the limiting magnitudes, reaching two magnitudes fainter than ROSS. Here we show the concept, the tests and the user level product we are now offering at REM.

Molinari, Emilio; Covino, Stefano; Crimi, Giuseppe; D'Alessio, Francesco; Incorvaia, Salvatore; Fugazza, Dino; Spanò, Paolo; Toso, Giorgio; Tresoldi, Daniela; Vitali, Fabrizio

2014-07-01

255

A systems biology perspective on Nrf2-mediated antioxidant response  

International Nuclear Information System (INIS)

Cells in vivo are constantly exposed to reactive oxygen species (ROS) generated endogenously and exogenously. To defend against the deleterious consequences of ROS, cells contain multiple antioxidant enzymes expressed in various cellular compartments to scavenge these toxic species. Under oxidative stresses, these antioxidant enzymes are upregulated to restore redox homeostasis. Such an adaptive response results from the activation of a redox-sensitive gene regulatory network mediated by nuclear factor E2-related factor 2. To more completely understand how the redox control system is designed by nature to meet homeostatic goals, we have examined the network from a systems perspective using engineering approaches. As with man-made control devices, the redox control system can be decomposed into distinct functional modules, including transducer, controller, actuator, and plant. Cells achieve specific performance objectives by utilizing nested feedback loops, feedforward control, and ultrasensitive signaling motifs, etc. Given that endogenously generated ROS are also used as signaling molecules, our analysis suggests a novel mode of action to explain oxidative stress-induced pathological conditions and diseases. Specifically, by adaptively upregulating antioxidant enzymes, oxidative stress may inadvertently attenuate ROS signals that mediate physiological processes, resulting in aberrations of cellular functions and adverse consequences. Lastly, by simultaneously considequences. Lastly, by simultaneously considering the two competing cellular tasks-adaptive antioxidant defense and ROS signaling-we re-examine the premise that dietary antioxidant supplements is generally beneficial to human health. Our analysis highlights some possible adverse effects of these widely consumed antioxidants.

256

Inhibition of Propionibacterium acnes-induced mediators of inflammation by Indian herbs.  

Science.gov (United States)

Propionibacterium acnes, an anaerobic pathogen, plays an important role in the pathogenesis of acne by inducing certain inflammatory mediators. These mediators include reactive oxygen species (ROS) and pro-inflammatory cytokines. In the present study, ROS, interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) were used as the major criteria for the evaluation of anti-inflammatory activity. To prove the anti-inflammatory effects of herbs, polymorphonuclear leukocytes (PMNL) and monocytes were treated with culture supernatant of P. acnes in the presence or absence of herbs. It was found that Rubia cordifolia, Curcuma longa, Hemidesmus indicus, and Azadirachta indica caused a statistically significant suppression of ROS from PMNL. Sphaeranthus indicus caused a smaller, still significant suppression of ROS. Aloe vera had no effect on ROS production. In the case of proinflammatory cytokine-induced monocytes, maximum suppression was shown by Azadirachta indica and Sphaeranthus indicus, followed by Hemidesmus indicus, Rubia cordifolia, and Curcuma longa. Aloe vera showed insignificant inhibitory activity. Thus, these herbs shows anti-inflammatory activity by suppressing the capacity of P. acnes-induced ROS and pro-inflammatory cytokines, the two important inflammatory mediators in acne pathogenesis. PMID:12622461

Jain, A; Basal, E

2003-01-01

257

Synthesis and biological evaluation of new pyrazol-4-ylpyrimidine derivatives as potential ROS1 kinase inhibitors.  

Science.gov (United States)

With the aim of discovering potent and selective kinase inhibitors targeting ROS1 kinase, we designed, synthesized and screened a series of new pyrazol-4-ylpyrimidine derivatives based on our previously discovered lead compound KIST301072. Compounds 6a-e and 7a-e showed good to excellent activities against ROS1 kinase, and seven out of tested compounds were more potent than KIST301072. Compound 7c was the most potent with IC50 of 24 nM. Moreover, compound 7c showed ROS1 inhibitory selectivity of about 170-fold, relative to that of ALK sharing about 49% amino acid sequence homology with ROS1 kinase in the kinase domain. In silico modeling of 7c at ROS1 active site revealed some essential features for ROS1 inhibitory activity. Based on this study as well as the previous studies, we could build a hypothetical model predicting the required essential features for ROS1 inhibitory activity. The model validity has been tested through a second set of compounds. PMID:25461320

Abdelazem, Ahmed Z; Al-Sanea, Mohammad M; Park, Byung Sun; Park, Hye Mi; Yoo, Kyung Ho; Sim, Taebo; Park, Jong Bae; Lee, Seung-Hoon; Lee, So Ha

2015-01-27

258

Regulation of ROS in transmissible gastroenteritis virus-activated apoptotic signaling  

Energy Technology Data Exchange (ETDEWEB)

Highlights: •TGEV infection induced ROS accumulation. •ROS accumulation is involved in TGEV-induced mitochondrial integrity impairment. •ROS is associated with p53 activation and apoptosis occurrence in TGEV-infected cells. -- Abstract: Transmissible gastroenteritis virus (TGEV), an enteropathogenic coronavirus, causes severe lethal watery diarrhea and dehydration in piglets. Previous studies indicate that TGEV infection induces cell apoptosis in host cells. In this study, we investigated the roles and regulation of reactive oxygen species (ROS) in TGEV-activated apoptotic signaling. The results showed that TGEV infection induced ROS accumulation, whereas UV-irradiated TGEV did not promote ROS accumulation. In addition, TGEV infection lowered mitochondrial transmembrane potential in PK-15 cell line, which could be inhibited by ROS scavengers, pyrrolidinedithiocarbamic (PDTC) and N-acetyl-L-cysteine (NAC). Furthermore, the two scavengers significantly inhibited the activation of p38 MAPK and p53 and further blocked apoptosis occurrence through suppressing the TGEV-induced Bcl-2 reduction, Bax redistribution, cytochrome c release and caspase-3 activation. These results suggest that oxidative stress pathway might be a key element in TGEV-induced apoptosis and TGEV pathogenesis.

Ding, Li [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158 (China); Zhao, Xiaomin; Huang, Yong; Du, Qian; Dong, Feng; Zhang, Hongling; Song, Xiangjun; Zhang, Wenlong [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China); Tong, Dewen, E-mail: dwtong@nwsuaf.edu.cn [College of Veterinary Medicine, Northwest A and F University, Yangling, Shaanxi 712100 (China)

2013-12-06

259

Fenretinide induces mitochondrial ROS and inhibits the mitochondrial respiratory chain in neuroblastoma.  

Science.gov (United States)

Fenretinide induces apoptosis in neuroblastoma by induction of reactive oxygen species (ROS). In this study, we investigated the role of mitochondria in fenretinide-induced cytotoxicity and ROS production in six neuroblastoma cell lines. ROS induction by fenretinide was of mitochondrial origin, demonstrated by detection of superoxide with MitoSOX, the scavenging effect of the mitochondrial antioxidant MitoQ and reduced ROS production in cells without a functional mitochondrial respiratory chain (Rho zero cells). In digitonin-permeabilized cells, a fenretinide concentration-dependent decrease in ATP synthesis and substrate oxidation was observed, reflecting inhibition of the mitochondrial respiratory chain. However, inhibition of the mitochondrial respiratory chain was not required for ROS production. Co-incubation of fenretinide with inhibitors of different complexes of the respiratory chain suggested that fenretinide-induced ROS production occurred via complex II. The cytotoxicity of fenretinide was exerted through the generation of mitochondrial ROS and, at higher concentrations, also through inhibition of the mitochondrial respiratory chain. PMID:19941060

Cuperus, Roos; Leen, René; Tytgat, Godelieve A M; Caron, Huib N; van Kuilenburg, André B P

2010-03-01

260

TOR Complex 2-Ypk1 Signaling Maintains Sphingolipid Homeostasis by Sensing and Regulating ROS Accumulation  

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Full Text Available Reactive oxygen species (ROS are produced during normal metabolism and can function as signaling molecules. However, ROS at elevated levels can damage cells. Here, we identify the conserved target of rapamycin complex 2 (TORC2/Ypk1 signaling module as an important regulator of ROS in the model eukaryotic organism, S. cerevisiae. We show that TORC2/Ypk1 suppresses ROS produced both by mitochondria as well as by nonmitochondrial sources, including changes in acidification of the vacuole. Furthermore, we link vacuole-related ROS to sphingolipids, essential components of cellular membranes, whose synthesis is also controlled by TORC2/Ypk1 signaling. In total, our data reveal that TORC2/Ypk1 act within a homeostatic feedback loop to maintain sphingolipid levels and that ROS are a critical regulatory signal within this system. Thus, ROS sensing and signaling by TORC2/Ypk1 play a central physiological role in sphingolipid biosynthesis and in the maintenance of cell growth and viability.

Brad J. Niles

2014-02-01

 
 
 
 
261

Regulation of ROS in transmissible gastroenteritis virus-activated apoptotic signaling  

International Nuclear Information System (INIS)

Highlights: •TGEV infection induced ROS accumulation. •ROS accumulation is involved in TGEV-induced mitochondrial integrity impairment. •ROS is associated with p53 activation and apoptosis occurrence in TGEV-infected cells. -- Abstract: Transmissible gastroenteritis virus (TGEV), an enteropathogenic coronavirus, causes severe lethal watery diarrhea and dehydration in piglets. Previous studies indicate that TGEV infection induces cell apoptosis in host cells. In this study, we investigated the roles and regulation of reactive oxygen species (ROS) in TGEV-activated apoptotic signaling. The results showed that TGEV infection induced ROS accumulation, whereas UV-irradiated TGEV did not promote ROS accumulation. In addition, TGEV infection lowered mitochondrial transmembrane potential in PK-15 cell line, which could be inhibited by ROS scavengers, pyrrolidinedithiocarbamic (PDTC) and N-acetyl-L-cysteine (NAC). Furthermore, the two scavengers significantly inhibited the activation of p38 MAPK and p53 and further blocked apoptosis occurrence through suppressing the TGEV-induced Bcl-2 reduction, Bax redistribution, cytochrome c release and caspase-3 activation. These results suggest that oxidative stress pathway might be a key element in TGEV-induced apoptosis and TGEV pathogenesis

262

ROS-triggered and regenerating anticancer nanosystem: An effective strategy to subdue tumor's multidrug resistance.  

Science.gov (United States)

Drug delivery strategies utilizing tumor microenvironment are recognized as a critical doorway to overcome multidrug resistance (MDR). However, the variability of tumor microenvironment at different disease stages would definitely minimize stimuli generation and eventually the therapeutic effects of these stimuli sensitive systems. Herein, we report a unique reactive oxygen species (ROS) triggered nanosystem that can replenish the ROS upon disassembly to maintain its high level. This was accomplished by a new amphiphilic polymer (TBH) composed of D-?-tocopherol polyethylene glycol 1000 succinate (TPGS), hyaluronic acid (HA) and arylboronic ester. As a linker of TPGS to HA, arylboronic ester could efficiently degrade in response to ROS resulting in dismantling of nanosystem followed by rapid release of TPGS. Owing to ROS inducing activity of TPGS with mitochondrial respiratory complex II, ROS regeneration was observed for TBH nanosystem both in MCF-7/ADR cells and tumor tissues xenografted with MCF-7/ADR cells. Furthermore, doxorubicin-loaded TBH nanosystem (DOX-TBH) revealed higher drug cytotoxicity due to enhanced retention effect on account of ROS triggered DOX release and P-gp inhibitory mechanism of TPGS. Moreover, HA significantly improved tumor targeting capability of DOX-TBH, while ROS based triggering and regenerating mechanism lead to marked inhibition of the tumor growth in the xenograft MCF-7/ADR tumor-bearing nude mice. PMID:25278256

Su, Zhigui; Chen, Minglei; Xiao, Yanyu; Sun, Minjie; Zong, Li; Asghar, Sajid; Dong, Mei; Li, Huipeng; Ping, Qineng; Zhang, Can

2014-12-28

263

Survey of tyrosine kinase signaling reveals ROS kinase fusions in human cholangiocarcinoma.  

Science.gov (United States)

Cholangiocarcinoma, also known as bile duct cancer, is the second most common primary hepatic carcinoma with a median survival of less than 2 years. The molecular mechanisms underlying the development of this disease are not clear. To survey activated tyrosine kinases signaling in cholangiocarcinoma, we employed immunoaffinity profiling coupled to mass spectrometry and identified DDR1, EPHA2, EGFR, and ROS tyrosine kinases, along with over 1,000 tyrosine phosphorylation sites from about 750 different proteins in primary cholangiocarcinoma patients. Furthermore, we confirmed the presence of ROS kinase fusions in 8.7% (2 out of 23) of cholangiocarcinoma patients. Expression of the ROS fusions in 3T3 cells confers transforming ability both in vitro and in vivo, and is responsive to its kinase inhibitor. Our data demonstrate that ROS kinase is a promising candidate for a therapeutic target and for a diagnostic molecular marker in cholangiocarcinoma. The identification of ROS tyrosine kinase fusions in cholangiocarcinoma, along with the presence of other ROS kinase fusions in lung cancer and glioblastoma, suggests that a more broadly based screen for activated ROS kinase in cancer is warranted. PMID:21253578

Gu, Ting-Lei; Deng, Xiaxing; Huang, Feizhou; Tucker, Meghan; Crosby, Katherine; Rimkunas, Victoria; Wang, Yi; Deng, Gang; Zhu, Lei; Tan, Zhiping; Hu, Yerong; Wu, Chunlin; Nardone, Julie; MacNeill, Joan; Ren, Jianmin; Reeves, Cynthia; Innocenti, Gregory; Norris, Brett; Yuan, Jin; Yu, Jian; Haack, Herbert; Shen, Baiyong; Peng, Chenghong; Li, Hongwei; Zhou, Xinmin; Liu, Xunyang; Rush, John; Comb, Michael J

2011-01-01

264

ROS production during symbiotic infection suppresses pathogenesis-related gene expression.  

Science.gov (United States)

Leguminous plants have exclusive ability to form symbiotic relationship with soil bacteria of the genus Rhizobium. Symbiosis is a complex process that involves multiple molecular signaling activities, such as calcium fluxes, production of reactive oxygen species (ROS) and synthesis of nodulation genes. We analyzed the role of ROS in defense gene expression in Medicago truncatula during symbiosis and pathogenesis. Studies in Arabidopsis thaliana showed that the induction of pathogenesis-related (PR) genes during systemic acquired resistance (SAR) is regulated by NPR1 protein, which resides in the cytoplasm as an oligomer. After oxidative burst and return of reducing conditions, the NPR1 undergoes monomerization and becomes translocated to the nucleus, where it functions in PR genes induction. We show that ROS production is both stronger and longer during symbiotic interactions than during interactions with pathogenic, nonhost or common nonpathogenic soil bacteria. Moreover, root cells inoculated with Sinorhizobium meliloti accumulated ROS in the cytosol but not in vacuoles, as opposed to Pseudomonas putida inoculation or salt stress treatment. Furthermore, increased ROS accumulation by addition of H?O? reduced the PR gene expression, while catalase had an opposite effect, establishing that the PR gene expression is opposite to the level of cytoplasmic ROS. In addition, we show that salicylic acid pretreatment significantly reduced ROS production in root cells during symbiotic interaction. PMID:22499208

Peleg-Grossman, Smadar; Melamed-Book, Naomi; Levine, Alex

2012-03-01

265

Development of an in vitro skin sensitization test based on ROS production in THP-1 cells.  

Science.gov (United States)

Recently, it has been reported that reactive oxygen species (ROS) produced by contact allergens can affect dendritic cell migration and contact hypersensitivity. The aim of the present study was to develop a new in vitro assay that could predict the skin sensitizing potential of chemicals by measuring ROS production in THP-1 (human monocytic leukemia cell line) cells. THP-1 cells were pre-loaded with a ROS sensitive fluorescent dye, 5-(and 6-)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA), for 15min, then incubated with test chemicals for 30min. The fluorescence intensity was measured by flow cytometry. For the skin sensitizers, 25 out of 30 induced over a 2-fold ROS production at more than 90% of cell viability. In contrast, increases were only seen in 4 out of 20 non-sensitizers. The overall accuracy for the local lymph node assay (LLNA) was 82% for 50 chemicals tested. A correlation was found between the estimated concentration showing 2-fold ROS production in the ROS assay and the EC3 values (estimated concentration required to induce positive response) of the LLNA. These results indicated that the THP-1 cell-based ROS assay was a rapid and highly sensitive detection system able to predict skin sensitizing potentials and potency of chemicals. PMID:23287046

Saito, Kazutoshi; Miyazawa, Masaaki; Nukada, Yuko; Sakaguchi, Hitoshi; Nishiyama, Naohiro

2013-03-01

266

TiO{sub 2} nanoparticle-induced ROS correlates with modulated immune cell function  

Energy Technology Data Exchange (ETDEWEB)

Design of non-toxic nanoparticles will be greatly facilitated by understanding the nanoparticle-cell interaction mechanism on a cell function level. Mast cells are important cells for the immune system's first line of defense, and we can utilize their exocytotic behavior as a model cellular function as it is a conserved process across cell types and species. Perturbations in exocytosis can also have implications for whole organism health. One proposed mode of toxicity is nanoparticle-induced reactive oxygen species (ROS), particularly for titanium dioxide (TiO{sub 2}) nanoparticles. Herein, we have correlated changes in ROS with the perturbation of the critical cell function of exocytosis, using UV light to induce greater levels of ROS in TiO{sub 2} exposed cells. The primary culture mouse peritoneal mast cells (MPMCs) were exposed to varying concentrations of TiO{sub 2} nanoparticles for 24 h. ROS content was determined using 2,7-dihydrodichlorofluorescein diacetate (DCFDA). Cellular viability was determined with the MTT and Trypan blue assays, and exocytosis was measured by the analytical electrochemistry technique of carbon-fiber microelectrode amperometry. MPMCs exposed to TiO{sub 2} nanoparticles experienced a dose-dependent increase in total ROS content. While there was minimal impact of ROS on cellular viability, there is a correlation between ROS amount and exocytosis perturbation. As nanoparticle-induced ROS increases, there is a significant decrease (45 %) in the number of serotonin molecules being released during exocytosis, increase (26 %) in the amount of time for each exocytotic granule to release, and decrease (28 %) in the efficiency of granule trafficking and docking. This is the first evidence that nanoparticle-induced ROS correlates with chemical messenger molecule secretion, possibly making a critical connection between functional impairment and mechanisms contributing to that impairment.

Maurer-Jones, Melissa A.; Christenson, Jenna R.; Haynes, Christy L., E-mail: chaynes@umn.edu [University of Minnesota, Department of Chemistry (United States)

2012-12-15

267

ATP stimulates PGE(2)/cyclin D1-dependent VSMCs proliferation via STAT3 activation: role of PKCs-dependent NADPH oxidase/ROS generation.  

Science.gov (United States)

Vascular smooth muscle cells (VSMCs) that function as synthetic units play important roles in cardiovascular diseases. Extracellular nucleotides, such as ATP, have been shown to act via activation of P2 purinoceptors implicated in various inflammatory diseases, we hypothesized that extracellular nucleotides contribute to vascular diseases via up-regulation of inflammatory proteins, including cyclooxygenase-2 (COX-2) and cytosolic phospholipase A2 (cPLA2) in VSMCs. However, the mechanisms of ATP-induced cPLA2 and COX-2 expression and PGE2 synthesis remain largely unclear. We showed that pretreatment with the inhibitors of STAT3 (CBE), NADPH oxidase [diphenyleneiodonium chloride (DPI) or apocynin (APO)], ROS [N-acetyl-l-cysteine (NAC)], and PKC (Ro-318220, Gö6983, or Rottlerin) or transfection with siRNAs of STAT3 and p47(phox) markedly inhibited ATP?S-induced cPLA2 and COX-2 mRNA/protein expression and promoter activity and PGE2 secretion. ATP?S further stimulated PKC, p47(phox), and STAT3 translocation. Moreover, ATP?S-induced STAT3 phosphorylation and translocation was inhibited by pretreatment with the inhibitors of PKC, NADPH oxidase, and ROS. ATP?S enhanced NADPH oxidase activity and ROS generation in VSMCs, which were reduced by pretreatment with Ro-318220, Gö6983, or Rottlerin. Finally, we found that ATP?S significantly induced cyclin D1 expression and VSMCs proliferation, which were inhibited by pretreatment with NAC, APO, DPI, Ro-318220, Gö6983, Rottlerin, or CBE or transfection with siRNAs of COX-2 and cyclin D1. We also demonstrated that ATP?S induced cyclin D1 expression via a PGE2-dependent pathway. These results suggested that ATP?S-induced cPLA2/COX-2 expression and PGE2 secretion is mediated through a PKC/NADPH oxidase/ROS/STAT3-dependent pathway in VSMCs. PMID:23318226

Lee, I-Ta; Lin, Chih-Chung; Wang, Chao-Hung; Cherng, Wen-Jin; Wang, Jong-Shyan; Yang, Chuen-Mao

2013-04-01

268

Investigating the protective effect of lithium against high glucose-induced neurotoxicity in PC12 cells: involvements of ROS, JNK and P38 MAPKs, and apoptotic mitochondria pathway.  

Science.gov (United States)

Hyperglycemia that occurs under the diabetic condition is a major cause of diabetic complications such as diabetic neuropathy, one of the most common diabetes-related complications. It is well known that hyperglycemia could result in generation of reactive oxygen species (ROS). Over production of ROS recommended as an important mediator for apoptotic signaling pathway as well as a key early event in the development of diabetic neuropathy. Recently, many studies have indicated that lithium has robust neuroprotective effect in relation to several neurodegenerative diseases. The present study aimed to examine effects of lithium on high glucose (HG)-induced neurotoxicity and to determine some of the underlying molecular mechanisms involved in this response in PC12 cells as a neuronal culture model for diabetic neuropathy. PC12 cells were pretreated with different concentrations of lithium for 7 days, exposed to HG for 24 h. Cell viability was measured by MTT assay. ROS and lipid peroxidation levels as well as superoxide dismutase activity were measured. In order to examine the underlying molecular mechanisms, the expressions of Bax, Bcl-2, Caspase-3, total and phosphorylated JNK and P38 MAPK were also analyzed by Western blotting. The present results indicated that pretreatment with 1 mM lithium has protected PC12 cells against HG-induced apoptotic cell death. It could reduce ROS generation, Bax/Bcl-2 ratio, Caspase-3 activation, and JNK and P38 MAPK phosphorylation. It may be concluded that in HG condition, lithium pretreatment could prevent mitochondrial apoptosis as well as JNK and P38 MAPK pathway in PC12 cells. PMID:25073869

Aminzadeh, A; Dehpour, A R; Safa, M; Mirzamohammadi, S; Sharifi, A M

2014-11-01

269

Mediation Analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mediating variables are prominent in psychological theory and research. A mediating variable transmits the effect of an independent variable on a dependent variable. Differences between mediating variables and confounders, moderators, and covariates are outlined. Statistical methods to assess mediation and modern comprehensive approaches are described. Future directions for mediation analysis are discussed.

Mackinnon, David P.; Fairchild, Amanda J.; Fritz, Matthew S.

2007-01-01

270

Characterization of ROS1 cDNA from a human glioblastoma cell line.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We have isolated and characterized a human ROS1 cDNA from the glioblastoma cell line SW-1088. The cDNA, 8.3 kilobases long, has the potential to encode a transmembrane tyrosine-specific protein kinase with a predicted molecular mass of 259 kDa. The putative extracellular domain of ROS1 is homologous to the extracellular domain of the sevenless gene product from Drosophila. No comparable similarities in the extracellular domains were found between ROS1 and other receptor-type tyrosine kinases....

Birchmeier, C.; O Neill, K.; Riggs, M.; Wigler, M.

1990-01-01

271

Generation of reactive oxygen species mediated by humic-like substances in atmospheric aerosols.  

Science.gov (United States)

Particulate matter (PM)-mediated reactive oxygen species (ROS) generation has been implicated in health effects posed by PM. Humic-like substances (HULIS) are an unresolved mixture of water-extracted organic compounds from atmospheric aerosol particles or isolated from fog/cloudwater samples. In this study, we use a cell-free dithiothreitol (DTT) assay to measure ROS production mediated by HULIS. The HULIS samples are isolated from aerosols collected at a rural location and a suburban location in the Pearl River Delta, China. In our experiments, ROS activities by residue metal ions in the HULIS fraction are suppressed by including a strong chelating agent in the DTT assay. Under conditions of DTT consumption not exceeding 90%, the HULIS-catalyzed oxidation of DTT follows the zero-order kinetics with respect to DTT concentration, and the rate of DTT oxidation is proportional to the dose of HULIS. The ROS activity of the aerosol HULIS, on a per unit mass basis is 2% of the ROS activity by a reference quinone compound, 1,4-naphthoquinone and exceeds that of two aquatic fulvic acids. The HULIS fraction in the ambient samples tested exhibits comparable ROS activities to the organic solvent extractable fraction, which would contain compounds such as quinones, a known organic compound class capable of catalyzing generation of ROS in cells. HULIS was found to be the major redox active constituent of the water-extractable organic fraction in PM. It is plausible that HULIS contains reversible redox sites, thereby serving as electron carriers to catalyze the formation of ROS. Our work suggests that HULIS could be an active PM component in generating ROS and further work is warranted to characterize its redox properties. PMID:22044074

Lin, Peng; Yu, Jian Zhen

2011-12-15

272

Triiodothyronine (T3) does not induce Rankl expression in rat Ros 17/2.8 cells / Triiodotironina (T3) não induz a expressão de Rankl em células de rato ROS 17/2.8  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A osteoclastogênese pode ser regulada via ativação do sistema RANK/RANKL (receptor ativador do fator nuclear kapa B/ ligante do receptor do fator nuclear kapa B), que é mediado pelos osteoblastos. Entretanto, o mecanismo de perda óssea induzido pelo T3 (triiodotironina) ainda é controverso. Neste es [...] tudo, a linhagem osteoblástica de células de rato ROS 17/2.8 foi tratada com T3 (10-8 M, 10-9 M e 10-10 M), e a expressão do mRNA do RANKL foi medida por RT-PCR semiquantitativo. Nossos resultados mostraram que as concentrações de T3 utilizadas não induziram significativamente a expressão do RANKL, comparado ao controle (sem tratamento hormonal). Estes dados sugerem que outros mecanismos, não relacionados ao sistema RANK/RANKL, são usados para ativar a diferenciação osteoclástica nestas células. Abstract in english Osteoclastogenesis may be regulated via activation of the RANK/RANKL (receptor activator of nuclear factor-kappa B/ receptor activator of nuclear factor-kappa B ligand) system, which is mediated by osteoblasts. However, the bone loss mechanism induced by T3 (triiodothyronine) is still controversial. [...] In this study, osteoblastic lineage rat cells (ROS 17/2.8) were treated with T3 (10-8 M, 10-9 M, and 10-10 M), and RANKL mRNA (messenger RNA) expression was measured by semiquantitative RT-PCR. Our results show that T3 concentrations used did not significantly enhance RANKL expression compared to controls without hormone treatment. This data suggests that other mechanisms, unrelated to the RANK/RANKL system, might be to activate osteoclast differentiation in these cells.

Patrícia P., Saraiva; Silvania S., Teixeira; Célia Regina, Nogueira; Carlos Roberto, Padovani.

2008-02-01

273

Comprehensive analysis of RET and ROS1 rearrangement in lung adenocarcinoma.  

Science.gov (United States)

The success of crizotinib in ALK-positive patients has elicited efforts to find new oncogenic fusions in lung cancer. These efforts have led to the discovery of novel oncogenic fusion genes such as ROS1 and RET. However, the molecular and clinicopathologic characteristics associated with RET or ROS1 fusion, compared with ALK fusion-positive lung cancer, remain unclear. We accordingly analyzed the clinicopathologic characteristics of RET- and ROS1-fusion-positive lung adenocarcinomas. We further performed immunohistochemistry and fluorescence in situ hybridization analysis (FISH) in 15 cases of RET and 9 cases of ROS1 fusion tumors by identified NanoString's nCounter screening. RET fusion-positive patients were younger in age, never-smokers, and in early T stage; ROS1 fusion-positive patients had a higher number of never-smokers compared with patients with quintuple-negative (EGFR-/KRAS-/ALK-/ROS1-/RET-) lung adenocarcinoma. Histologically, RET and ROS1 fusion tumors share the solid signet-ring cell and mucinous cribriform pattern, as previously mentioned in the histology of ALK fusion tumors. Therefore, it can be presumed that fusion gene-associated lung adenocarcinomas share similar histologic features. In immunohistochemistry, the majority of 15 RET and 9 ROS1 fusion-positive cases showed positivity of more than moderate intensity and cytoplasmic staining for RET and ROS1 proteins, respectively. In FISH, the majority of RET and ROS1 rearrangement showed two signal patterns such as one fusion signal and two separated green and orange signals (1F1G1O) and an isolated 3' green signal pattern (1F1G). Our study has provided not only characteristics of fusion gene-associated histologic features but also a proposal for a future screening strategy that will enable clinicians to select cases needed to be checked for ROS1 and RET rearrangements based on clinicohistologic features.Modern Pathology advance online publication, 19 September 2014; doi:10.1038/modpathol.2014.107. PMID:25234288

Lee, Seung Eun; Lee, Boram; Hong, Mineui; Song, Ji-Young; Jung, Kyungsoo; Lira, Maruja E; Mao, Mao; Han, Joungho; Kim, Jhingook; Choi, Yoon-La

2014-09-19

274

Ionizing radiation regulates cardiac Ca handling via increased ROS and activated CaMKII  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ionizing radiation (IR) is an integral part of modern multimodal anti-cancer therapies. IR involves the formation of reactive oxygen species (ROS) in targeted tissues. This is associated with subsequent cardiac dysfunction when applied during chest radiotherapy. We hypothesized that IR (i.e., ROS)-dependently impaired cardiac myocytes’ Ca handling might contribute to IR-dependent cardiocellular dysfunction. Isolated ventricular mouse myocytes and the mediastinal area of anaesthetized mice (...

Sag, Can; Wolff, Hendrik; Neumann, Kay; Opiela, Marie-kristin; Zhang, Juqian; Steuer, Felicia; Sowa, Thomas; Gupta, Shamindra; Schirmer, Markus; Hu?nlich, Mark; Rave-fra?nk, Margret; Hess, Clemens; Anderson, Mark; Shah, Ajay; Christiansen, Hans

2013-01-01

275

Oncogene-induced Nrf2 transcription promotes ROS detoxification and tumorigenesis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reactive oxygen species (ROS) are mutagenic and may thereby promote cancer1. Normally, ROS levels are tightly controlled by an inducible antioxidant program that responds to cellular stressors and is predominantly regulated by the transcription factor Nrf2 and its repressor protein Keap12-5. In contrast to the acute physiological regulation of Nrf2, in neoplasia there is evidence for increased basal activation of Nrf2. Indeed, somatic mutations that disrupt the Nrf2-Keap1 interaction to stabi...

Denicola, Gina M.; Karreth, Florian A.; Humpton, Timothy J.; Gopinathan, Aarthi; Wei, Cong; Frese, Kristopher; Mangal, Dipti; Yu, Kenneth H.; Yeo, Charles J.; Calhoun, Eric S.; Scrimieri, Francesca; Winter, Jordan M.; Hruban, Ralph H.; Iacobuzio-donahue, Christine; Kern, Scott E.

2011-01-01

276

The role of ROS signaling in cross-tolerance: from model to crop  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reactive oxygen species (ROS) are key signaling molecules produced in response to biotic and abiotic stresses that trigger a variety of plant defense responses. Cross-tolerance, the enhanced ability of a plant to tolerate multiple stresses, has been suggested to result partly from overlap between ROS signaling mechanisms. Cross-tolerance can manifest itself both as a positive genetic correlation between tolerance to different stresses (inherent cross-tolerance), and as the priming of systemic...

Perez, Ilse Barrios; Brown, Patrick J.

2014-01-01

277

ROS production during symbiotic infection suppresses pathogenesis-related gene expression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Leguminous plants have exclusive ability to form symbiotic relationship with soil bacteria of the genus Rhizobium. Symbiosis is a complex process that involves multiple molecular signaling activities, such as calcium fluxes, production of reactive oxygen species (ROS) and synthesis of nodulation genes. We analyzed the role of ROS in defense gene expression in Medicago truncatula during symbiosis and pathogenesis. Studies in Arabidopsis thaliana showed that the induction of pathogenesis-relate...

Peleg-grossman, Smadar; Melamed-book, Naomi; Levine, Alex

2012-01-01

278

A preliminary cyber-physical security assessment of the Robot Operating System (ROS)  

Science.gov (United States)

Over the course of the last few years, the Robot Operating System (ROS) has become a highly popular software framework for robotics research. ROS has a very active developer community and is widely used for robotics research in both academia and government labs. The prevalence and modularity of ROS cause many people to ask the question: "What prevents ROS from being used in commercial or government applications?" One of the main problems that is preventing this increased use of ROS in these applications is the question of characterizing its security (or lack thereof). In the summer of 2012, a crowd sourced cyber-physical security contest was launched at the cyber security conference DEF CON 20 to begin the process of characterizing the security of ROS. A small-scale, car-like robot was configured as a cyber-physical security "honeypot" running ROS. DEFFCON-20 attendees were invited to find exploits and vulnerabilities in the robot while network traffic was collected. The results of this experiment provided some interesting insights and opened up many security questions pertaining to deployed robotic systems. The Federal Aviation Administration is tasked with opening up the civil airspace to commercial drones by September 2015 and driverless cars are already legal for research purposes in a number of states. Given the integration of these robotic devices into our daily lives, the authors pose the following question: "What security exploits can a motivated person with little-to-no experience in cyber security execute, given the wide availability of free cyber security penetration testing tools such as Metasploit?" This research focuses on applying common, low-cost, low-overhead, cyber-attacks on a robot featuring ROS. This work documents the effectiveness of those attacks.

McClean, Jarrod; Stull, Christopher; Farrar, Charles; Mascareñas, David

2013-05-01

279

Reactive oxygen species (ROS – a family of fate deciding molecules pivotal in constructive inflammation and wound healing  

Directory of Open Access Journals (Sweden)

Full Text Available Wound healing requires a fine balance between the positive and deleterious effects of reactive oxygen species (ROS; a group of extremely potent molecules, rate limiting in successful tissue regeneration. A balanced ROS response will debride and disinfect a tissue and stimulate healthy tissue turnover; suppressed ROS will result in infection and an elevation in ROS will destroy otherwise healthy stromal tissue. Understanding and anticipating the ROS niche within a tissue will greatly enhance the potential to exogenously augment and manipulate healing.Tissue engineering solutions to augment successful healing and remodelling of wounded or diseased tissue rely on a controlled balance between the constructive and destructive capacity of the leukocyte secretome, including ROS.This review comprehensively considers leukocyte derived ROS in tissue repair with particular interest in surgical intervention with inclusion of a biomaterial. The article considers ROS fundamental chemistry, formation, stimulation and clearance before applying this to discuss the implications of ROS in healing tissue with and without a biomaterial. We also systematically discuss ROS in leukocyte signalling and compare and contrast experimental means of measuring ROS.

N Bryan

2012-09-01

280

Selenocysteine derivative overcomes TRAIL resistance in melanoma cells: evidence for ROS-dependent synergism and signaling crosstalk.  

Science.gov (United States)

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), as one of the most promising targeted drug for new cancer therapeutics, is limited in clinical application by the evolution of resistance in many cancer cell lines, especially in malignant melanoma. Thus, it is urgently needed to identify chemosensitizers to enhance the apoptotic inducing ef?cacy of TRAIL and overcome resistance of malignant melanoma cells. Herein, we reported that 3,3'-diselenodipropionic acid (DSeA), a Selenocysteine derivative, could synergistically enhance the growth inhibitory effect of TRAIL on A375 melanoma cells though induction of ROS-dependent apoptosis with involvement of PTEN-mediated Akt inactivation and DNA damage-mediated p53 phosphorylation, which subsequently activated mitochondrial and death receptor apoptotic pathways. Moreover, silencing of p53 down-regulated the expression levels of p53-inducible genes, and effectively blocked the cell apoptosis. Suppression of PI3K signi?cantly increased the apoptotic cell death. In contrast, antioxidants effectively reversed the cell apoptosis through regulation of Akt and p53 signaling pathways. Taken together, the combination of DSeA and TRAIL could be a novel strategy to overcome TRAIL resistance in malignant melanoma, and DSeA may be candidates for further evaluation as a chemosensitizer in clinical trails. PMID:25277183

Cao, Wenqiang; Li, Xiaoling; Zheng, Shanyuan; Zheng, Wenjie; Wong, Yum-Shing; Chen, Tianfeng

2014-09-15

 
 
 
 
281

Mitochondrial Behaviour in the Early Stages of ROS Stress Leading to Cell Death in Arabidopsis thaliana  

Science.gov (United States)

• Background and Aims Reactive oxygen species (ROS) are involved in triggering cell death. To visualize mitochondrial behaviour under ROS stress, transgenic arabidopsis plants possessing mitochondrial-targeted GFP (S65T) were studied. • Methods Arabidopsis leaves were treated with ROS and ROS-inducing chemicals such as hydrogen peroxide, paraquat and menadione. Microscopic observations were carried out using a confocal laser scanning microscope system, and electrolyte leakage was also monitored. • Key Results After treatment, mitochondria showed morphological changes from a bacillus-like to a round shape. The size of mitochondria treated with H2O2 decreased by half compared with controls. Concurrently, cytoplasmic streaming was blocked and mitochondria eventually swelled. Treatment of leaves with butanedione monoxime, an inhibitor of myosin ATPase, resulted in similar behaviour of mitochondria to that under ROS stress. • Conclusions The results indicate that morphological changes of mitochondria and cessation of cytoplasmic streaming may interact, and this phenomenon is one of the features of ROS stress-induced cell death. PMID:15944174

YOSHINAGA, KEIKO; ARIMURA, SHIN-ICHI; NIWA, YASUO; TSUTSUMI, NOBUHIRO; UCHIMIYA, HIROFUMI; KAWAI-YAMADA, MAKI

2005-01-01

282

Looking into a Conceptual Framework of ROS–miRNA–Atrial Fibrillation  

Directory of Open Access Journals (Sweden)

Full Text Available Atrial fibrillation (AF has been recognized as a major cause of cardiovascular-related morbidity and mortality. MicroRNAs (miRNAs represent recent additions to the collection of biomolecules involved in arrhythmogenesis. Reactive oxygen species (ROS have been independently linked to both AF and miRNA regulation. However, no attempts have been made to investigate the possibility of a framework composed of ROS–miRNA–AF that is related to arrhythmia development. Therefore, this review was designed as an attempt to offer a new approach to understanding AF pathogenesis. The aim of this review was to find and to summarize possible connections that exist among AF, miRNAs and ROS to understand the interactions among the molecular entities underlying arrhythmia development in the hopes of finding unappreciated mechanisms of AF. These findings may lead us to innovative therapies for AF, which can be a life-threatening heart condition. A systemic literature review indicated that miRNAs associated with AF might be regulated by ROS, suggesting the possibility that miRNAs translate cellular stressors, such as ROS, into AF pathogenesis. Further studies with a more appropriate experimental design to either prove or disprove the existence of an ROS–miRNA–AF framework are strongly encouraged.

Seahyoung Lee

2014-11-01

283

Looking into a Conceptual Framework of ROS-miRNA-Atrial Fibrillation.  

Science.gov (United States)

Atrial fibrillation (AF) has been recognized as a major cause of cardiovascular-related morbidity and mortality. MicroRNAs (miRNAs) represent recent additions to the collection of biomolecules involved in arrhythmogenesis. Reactive oxygen species (ROS) have been independently linked to both AF and miRNA regulation. However, no attempts have been made to investigate the possibility of a framework composed of ROS-miRNA-AF that is related to arrhythmia development. Therefore, this review was designed as an attempt to offer a new approach to understanding AF pathogenesis. The aim of this review was to find and to summarize possible connections that exist among AF, miRNAs and ROS to understand the interactions among the molecular entities underlying arrhythmia development in the hopes of finding unappreciated mechanisms of AF. These findings may lead us to innovative therapies for AF, which can be a life-threatening heart condition. A systemic literature review indicated that miRNAs associated with AF might be regulated by ROS, suggesting the possibility that miRNAs translate cellular stressors, such as ROS, into AF pathogenesis. Further studies with a more appropriate experimental design to either prove or disprove the existence of an ROS-miRNA-AF framework are strongly encouraged. PMID:25431922

Lee, Seahyoung; Choi, Eunhyun; Cha, Min-Ji; Hwang, Ki-Chul

2014-01-01

284

Genetic silencing of Nrf2 enhances X-ROS in dysferlin-deficient muscle  

Directory of Open Access Journals (Sweden)

Full Text Available Oxidative stress is a critical disease modifier in the muscular dystrophies. Recently, we discovered a pathway by which mechanical stretch activates NADPH Oxidase 2 (NoX2 dependent ROS generation (X-ROS. Our work in dystrophic skeletal muscle revealed that X-ROS is excessive in dystrophin-deficient (mdx skeletal muscle and contributes to muscle injury susceptibility, a hallmark of the dystrophic process. We also observed widespread alterations in expression of genes associated with the X-ROS pathway and redox homeostasis in muscles from both Duchenne muscular dystrophy patients and mdx mice. As nuclear factor erythroid 2-related factor 2 (Nrf2 plays an essential role in the transcriptional regulation of genes involved in redox homeostasis, we hypothesized that Nrf2 deficiency may contribute to enhanced X-ROS signaling by reducing redox buffering. To directly test the effect of diminished Nrf2 activity, Nrf2 was genetically silenced in the A/J model of dysferlinopathy - a model with a mild histopathologic and functional phenotype. Nrf2-deficient A/J mice exhibited significant muscle-specific functional deficits, histopathologic abnormalities, and dramatically enhanced X-ROS compared to control A/J and WT mice, both with functional Nrf2. Having identified that reduced Nrf2 activity is a negative disease modifier, we propose that strategies targeting Nrf2 activation may address the generalized reduction in redox homeostasis to halt or slow dystrophic progression.

ChristopherWilliamWard

2014-02-01

285

Activation of volume-sensitive outwardly rectifying chloride channel by ROS contributes to ER stress and cardiac contractile dysfunction: involvement of CHOP through Wnt.  

Science.gov (United States)

Endoplasmic reticulum (ER) stress occurring in stringent conditions is critically involved in cardiomyocytes apoptosis and cardiac contractile dysfunction (CCD). However, the molecular machinery that mediates cardiac ER stress and subsequent cell death remains to be fully deciphered, which will hopefully provide novel therapeutic targets for these disorders. Here, we establish tunicamycin-induced model of cardiomyocyte ER stress, which effectively mimicks pathological stimuli to trigger CCD. Tunicamycin activates volume-sensitive outward rectifying Cl(-) currents. Blockade of the volume-sensitive outwardly rectifying (VSOR) Cl(-) channel by 4,4'-diisothiocya-natostilbene-2,2'-disulfonic acid (DIDS), a non-selective Cl(-) channel blocker, and 4-(2-butyl-6,7-dichlor-2-cyclopentyl-indan-1-on-5-yl) oxybutyric acid (DCPIB), a selective VSOR Cl(-) channel blocker, improves cardiac contractility, which correlates with suppressed ER stress through inhibiting the canonical GRP78/eIF2?/ATF4 and XBP1 pathways, and promotes survival of cardiomyocytes by inverting tunicamycin-induced decrease of Wnt through the CHOP pathway. VSOR activation of tunicamycin-treated cardiomyocytes is attributed to increased intracellular levels of reactive oxygen species (ROS). Our study demonstrates a pivotal role of ROS/VSOR in mediating ER stress and functional impairment of cardiomyocytes via the CHOP-Wnt pathway, and suggests the therapeutic values of VSOR Cl(-) channel blockers against ER stress-associated cardiac anomalies. PMID:25412307

Shen, M; Wang, L; Wang, B; Wang, T; Yang, G; Shen, L; Wang, T; Guo, X; Liu, Y; Xia, Y; Jia, L; Wang, X

2014-01-01

286

Saxifragifolin D induces the interplay between apoptosis and autophagy in breast cancer cells through ROS-dependent endoplasmic reticulum stress.  

Science.gov (United States)

Breast cancer is the leading cause of cancer death among females, and novel chemotherapeutic drugs for treating breast cancer are needed urgently. Saxifragifolin D (SD) was isolated by our group from Androsace umbellata which is commonly used to treat solid tumor. In this study, we evaluated its growth inhibitory effect on breast cancer cells and explored the underlying molecular mechanisms. Our results showed that SD inhibited the growth of both MCF-7 and MDA-MB-231 cells significantly. Mechanistic studies demonstrated that SD induced apoptosis through mitochondrial apoptotic pathway. Evidence of SD-induced autophagy included the occurrence of autophagic vacuoles, up-regulation of LC3-II, Beclin1 and Vps34. Inhibition of autophagy by bafilomycin A1 or Beclin1 siRNA pretreatment decreased the ratio of apoptosis, indicating that autophagy induction contributes to apoptosis and is required for the latter. SD was also found to induce endoplasmic reticulum stress, accompanied by ROS production, increase of intracellular calcium and up-regulation of Bip, IRE1? and XBP-1s. Inhibition of endoplasmic reticulum stress by N-acetyl-l-cysteine, tauroursodeoxycholic acid or IRE1? siRNA pretreatment could suppress both apoptosis and autophagy. Besides, increases in CHOP, calnexin, calpain, p-JNK and p-Bcl-2 were followed by subsequent dissociation of Beclin1 from Bcl-2, further suggesting endoplasmic reticulum stress to be the common signaling pathway shared by SD-induced apoptosis and autophagy. In conclusion, SD inhibits breast cancer cell growth and induces interplay between apoptosis and autophagy through ROS-mediated endoplasmic reticulum stress. It will provide molecular bases for developing SD into a drug candidate for the treatment of breast cancer. PMID:23348250

Shi, Jun-Min; Bai, Liang-Liang; Zhang, Dong-Mei; Yiu, Anita; Yin, Zhi-Qi; Han, Wei-Li; Liu, Jun-Shan; Li, Yong; Fu, Deng-Yue; Ye, Wen-Cai

2013-04-01

287

Streptolysin-O induces release of glycosylphosphatidylinositol-anchored alkaline phosphatase from ROS cells by vesiculation independently of phospholipase action.  

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Streptolysin-O (SLO), a cholesterol-binding agent, was used for studies on the release of glycosylphosphatidylinositol (GPI)-anchored alkaline phosphatase (AP) from ROS cells. Treatment of cells with SLO resulted in a time- and concentration-dependent release of AP into the extracellular medium. This release was potentiated by Ca2+ and bovine serum, but not by GPI-specific phospholipase D (GPI-PLD) purified from bovine serum. The released AP distributed to the detergent phase after Triton X-114 phase separation. This result suggested that the released AP contained an intact GPI anchor, and thus both proteolysis and anchor degradation by anchor-specific hydrolases, including GPI-PLD, as the potential mechanisms for SLO-mediated AP release were ruled out. The released AP sedimented at 100,000 g. A substantial amount of lipids was detected in the 100,000 g pellet. Cholesterol and sphingomyelin were enriched in SLO-released material, compared with intact cells. These results were consistent with vesiculation as the mechanism for SLO induction of AP release. Two other cholesterol-binding agents, saponin and digitonin, were also able to release AP, possibly by a similar vesiculation mechanism, whereas others, including nystatin, filipin and beta-escin, failed to elicit any AP release. Eight GPI-anchored proteins were identified in ROS cells, and all were substantially enriched in the vesicles released by SLO. Taken together, these results do not provide any support for the hypothesis that the clustering of GPI-anchored proteins in the plasma membrane is responsible for their resistance to GPI-PLD cleavage. Images Figure 5 Figure 6 PMID:7832771

Xie, M; Low, M G

1995-01-01

288

Ca2+-mediated mitochondrial reactive oxygen species metabolism augments Wnt/?-catenin pathway activation to facilitate cell differentiation.  

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Emerging evidence suggests that reactive oxygen species (ROS) can stimulate the Wnt/?-catenin pathway in a number of cellular processes. However, potential sources of endogenous ROS have not been thoroughly explored. Here, we show that growth factor depletion in human neural progenitor cells induces ROS production in mitochondria. Elevated ROS levels augment activation of Wnt/?-catenin signaling that regulates neural differentiation. We find that growth factor depletion stimulates the release of Ca(2+) from the endoplasmic reticulum stores. Ca(2+) subsequently accumulates in the mitochondria and triggers ROS production. The inhibition of mitochondrial Ca(2+) uptake with simultaneous growth factor depletion prevents the rise in ROS metabolism. Moreover, low ROS levels block the dissociation of the Wnt effector Dishevelled from nucleoredoxin. Attenuation of the response amplitudes of pathway effectors delays the onset of the Wnt/?-catenin pathway activation and results in markedly impaired neuronal differentiation. Our findings reveal Ca(2+)-mediated ROS metabolic cues that fine-tune the efficiency of cell differentiation by modulating the extent of the Wnt/?-catenin signaling output. PMID:25124032

Rharass, Tareck; Lemcke, Heiko; Lantow, Margareta; Kuznetsov, Sergei A; Weiss, Dieter G; Panáková, Daniela

2014-10-01

289

Antimalarial action of artesunate involves DNA damage mediated by reactive oxygen species.  

Science.gov (United States)

Artemisinin-based combination therapy (ACT) is the recommended first-line treatment for Plasmodium falciparum malaria. It has been suggested that the cytotoxic effect of artemisinin is mediated by free radicals followed by the alkylation of P. falciparum proteins. The endoperoxide bridge, the active moiety of artemisinin derivatives, is cleaved in the presence of ferrous iron, generating reactive oxygen species (ROS) and other free radicals. However, the emergence of resistance to artemisinin in P. falciparum underscores the need for new insights into the molecular mechanisms of antimalarial activity of artemisinin. Here we show that artesunate (ART) induces DNA double-strand breaks in P. falciparum in a physiologically relevant dose- and time-dependent manner. DNA damage induced by ART was accompanied by an increase in the intracellular ROS level in the parasites. Mannitol, a ROS scavenger, reversed the cytotoxic effect of ART and reduced DNA damage, and modulation of glutathione (GSH) levels was found to impact ROS and DNA damage induced by ART. Accumulation of ROS, increased DNA damage, and the resulting antiparasite effect suggest a causal relationship between ROS, DNA damage, and parasite death. Finally, we also show that ART-induced ROS production involves a potential role for NADPH oxidase, an enzyme involved in the production of superoxide anions. Our results with P. falciparum provide novel insights into previously unknown molecular mechanisms underlying the antimalarial activity of artemisinin derivatives and may help in the design of next-generation antimalarial drugs against the most virulent Plasmodium species. PMID:25348537

Gopalakrishnan, Anusha M; Kumar, Nirbhay

2015-01-01

290

Recent Advances in Intracellular and In Vivo ROS Sensing: Focus on Nanoparticle and Nanotube Applications  

Directory of Open Access Journals (Sweden)

Full Text Available Reactive oxygen species (ROS are increasingly being implicated in the regulation of cellular signaling cascades. Intracellular ROS fluxes are associated with cellular function ranging from proliferation to cell death. Moreover, the importance of subtle, spatio-temporal shifts in ROS during localized cellular signaling events is being realized. Understanding the biochemical nature of the ROS involved will enhance our knowledge of redox-signaling. An ideal intracellular sensor should therefore resolve real-time, localized ROS changes, be highly sensitive to physiologically relevant shifts in ROS and provide specificity towards a particular molecule. For in vivo applications issues such as bioavailability of the probe, tissue penetrance of the signal and signal-to-noise ratio also need to be considered. In the past researchers have heavily relied on the use of ROS-sensitive fluorescent probes and, more recently, genetically engineered ROS sensors. However, there is a great need to improve on current methods to address the above issues. Recently, the field of molecular sensing and imaging has begun to take advantage of the unique physico-chemical properties of nanoparticles and nanotubes. Here we discuss the recent advances in the use of these nanostructures as alternative platforms for ROS sensing, with particular emphasis on intracellular and in vivo ROS detection and quantification.

Larissa M. Uusitalo

2012-08-01

291

[Mitochondrial dysfunction induced by excessive ROS/RNS-metabolic cardiovascular disease and traditional Chinese medicines intervention].  

Science.gov (United States)

Metabolic cardiovascular disease is a type of disease which almost caused by body carbohydrate and lipid metabolism dysfunction. Type 2 diabetes mellitus is a typical metabolic disease. It not only lead to the insulin resistance but also related to atherosclerosis. Oxidative stress is produced by the reactive oxygen/nitrogen species (ROS/RNS). Oxidative stress and its consequence events play important roles in atherosclerosis (AS). Mitochondria are both sources and targets of reactive oxygen and/or nitrogen species (ROS/RNS), and there is growing evidence that mitochondrial dysfunction may be relevant intermediate mechanism by which cardiovascular risk factors lead to the formation of vascular lesions. Several cardiovascular risk factors are demonstrated causes of mitochondrial damage. This review starts with excessive ROS/RNS-induced mitochondrial dysfunction. The authors emphasize the relationship among axis of excessive ROS/RNS-mitochondrial dysfunction-apoptosis-atherosclerosis. They also introduce several traditional Chinese medicines such as Ophiopogon japonicus, butin, Panax ginseng, Pueraria lobata, Solanum lyratum and so on in the treatment of relevant diseases through anti-ROS/RNS mechanism. Moreover, the TCMs also can anti-cancer and anti-fatigue,which show the speciality of TCMs different from the single effect of classical western medicines. PMID:22121816

Zhang, Chenchen; Liu, Jun; Pan, Huijun; Yang, Xiaolu; Bian, Ka

2011-09-01

292

Phorbol ester and light-induced endogenous phosphorylation of rat retinal rod outer segment (ROS) proteins  

International Nuclear Information System (INIS)

The authors have previously described the presence of a C-kinase in bovine ROS and its in vitro activation by light in crude rat ROS. In this study, they have labelled the retinas with 33Pi by intravitreal injection and compared the phosphorylation pattern of ROS proteins induced by light and activators of the C-kinase phosphorylation system. Except for light treatment, all procedures were carried out in complete darkness using an infrared image converter. Incubation of 33P-labelled retinas in light for 5 minutes resulted in the phosphorylation of rhodopsin, 80,65,47,44, and 15kd proteins of crude ROS. Incubation of 33P-labelled retinas with 5?M 12-0-tetradecanoylphorbol-13-acetate (TPA) resulted in the phosphorylation of 80,65,47,44,33, and 15 kd proteins of crude ROS. The complete darkness control did not exhibit any phosphorylation or proteins whereas the red light control exhibited variable low phosphorylation of 80,47,44, and 15kd proteins. 1-oleoyl-2-acetyl-glycerol (OAG) at 500?g/ml caused the phosphorylation of the same proteins as observed with TPA. TPA (0.5-500?M) and OAG (150-500?g/ml) did not induce rhodopsin phosphorylation. Since light, TPA and OAG exhibit similarities in the phosphorylation patterns of proteins (except for rhodopsin), these results suggest at least a partial linkage of light and C-kinase effects in vivo

293

??ALA-PDT?HL60????????? ROS Detection in HL60 Based on ALA-PDT  

Directory of Open Access Journals (Sweden)

Full Text Available ????????(photodynamic therapy, PDT?????????????????????PDT????????????????????PDT?????????????????????????????????ALA-PDT?HL60???????????????????ALA???10 mM/L??????4 h??????60 min???????????????????????HL60?????????PDT???93.2%?With the development of the basic research of photodynamic therapy (PDT and a wide range of potential clinical applications have be carried out. The monitoring of reactive oxygen species (ROS which produced in PDT has become a hot issue of PDT research in recent years. In the paper, the status of ROS in HL60 cells were investigated by fluorescence spectra acquired during PDT. The results showed that the largest number of ROS in PDT was achieved at the optimized conditions(the cells incubation time is 4 hours, the added concentration of ALA is 10 mM/L, in which up to 93.2% PDT efficiency for the HL60 Cells can be obtained within 60 minutes.

???

2011-12-01

294

Effects of a cationic PAMAM dendrimer on photosynthesis and ROS production of Chlamydomonas reinhardtii.  

Science.gov (United States)

Poly(amidoamine) (PAMAM) dendrimers hold great promises for biomedicine. This study sought to examine the toxicity of generation 4 (G4) cationic PAMAM dendrimer to the green microalga, Chlamydomonas reinhardtii, using physiological and molecular biomarkers. Results revealed that the G4 dendrimer at 15 and 25 nM stimulated the photosynthetic process and the production of reactive oxygen species (ROS) in algae. However, the over-production of ROS did not induce the expression of antioxidant enzyme genes, catalase and glutathione peroxidase. In addition, genes encoding light-harvesting proteins (lhca and lhcb), a ferredoxin (fdx) and an oxygen-evolving enhancer protein (psb) involved in photosynthesis were repressed after treatment. Nevertheless, the expression of the lhcbm9 gene, encoding a major light harvesting polypeptide, was increased. These results suggest that the strong modulation of photosynthesis induced by the dendrimer could lead to elevated ROS levels in microalgae. PMID:21554014

Petit, Anne-Noëlle; Debenest, Timothée; Eullaffroy, Philippe; Gagné, François

2012-05-01

295

Elucidating hormonal/ROS networks during seed germination: insights and perspectives  

DEFF Research Database (Denmark)

While authors have traditionally emphasized the deleterious effects of reactive oxygen species (ROS) on seed biology, their role as signaling molecules during seed dormancy alleviation and germination is now the focus of many studies around the world. Over the last few years, studies using “-omics” technologies together with physiological and biochemical approaches have revealed that seed germination is a very complex process that depends on multiple biochemical and molecular variables. The pivotal role of phytohormones in promoting germination now appears to be interdependent with ROS metabolism, involving mitogen-activated protein kinase cascade activation, gene expression and post-translational protein modifications. This review is, thus, an attempt to summarize the new discoveries involving ROS and seed germination. The study of these interactions may supply markers of seed quality that might eventually be used in breeding programs to improve crop yields.

Diaz-Vivancos, Pedro; Barba Espin, Gregorio

2013-01-01

296

Reactive oxygen species (ROS) generation inhibited by aporphine and phenanthrene alkaloids semi-synthesized from natural boldine.  

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Four phenanthrene and one aporphine alkaloids semi-synthesized from boldine were evaluated for their inhibitory effect on reactive oxygen species (ROS) generation. ROS generation by neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine was inhibited in a concentration dependent manner. Alkaloids exerted similar inhibitory effect in the hypoxanthine-xanthine oxidase system than in stimulated neutrophils, which could be attributed to a direct ROS scavenging activity. None of the alkaloids assayed had any effect on xanthine oxidase activity. Therefore the synthesized alkaloids might constitute an alternative therapy in inflammation disorders in which ROS generation is involved. PMID:15187389

Milián, Lara; Estellés, Rossana; Abarca, Belén; Ballesteros, Rafael; Sanz, María Jesús; Blázquez, María Amparo

2004-06-01

297

Thymoquinone inhibits tumor growth and induces apoptosis in a breast cancer xenograft mouse model: the role of p38 MAPK and ROS.  

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Due to narrow therapeutic window of cancer therapeutic agents and the development of resistance against these agents, there is a need to discover novel agents to treat breast cancer. The antitumor activities of thymoquinone (TQ), a compound isolated from Nigella sativa oil, were investigated in breast carcinoma in vitro and in vivo. Cell responses after TQ treatment were assessed by using different assays including MTT assay, annexin V-propidium iodide staining, Mitosox staining and Western blot. The antitumor effect was studied by breast tumor xenograft mouse model, and the tumor tissues were examined by histology and immunohistochemistry. The level of anti-oxidant enzymes/molecules in mouse liver tissues was measured by commercial kits. Here, we show that TQ induced p38 phosphorylation and ROS production in breast cancer cells. These inductions were found to be responsible for TQ's anti-proliferative and pro-apoptotic effects. Moreover, TQ-induced ROS production regulated p38 phosphorylation but not vice versa. TQ treatment was found to suppress the tumor growth and this effect was further enhanced by combination with doxorubicin. TQ also inhibited the protein expression of anti-apoptotic genes, such as XIAP, survivin, Bcl-xL and Bcl-2, in breast cancer cells and breast tumor xenograft. Reduced Ki67 and increased TUNEL staining were observed in TQ-treated tumors. TQ was also found to increase the level of catalase, superoxide dismutase and glutathione in mouse liver tissues. Overall, our results demonstrated that the anti-proliferative and pro-apoptotic effects of TQ in breast cancer are mediated through p38 phosphorylation via ROS generation. PMID:24098377

Woo, Chern Chiuh; Hsu, Annie; Kumar, Alan Prem; Sethi, Gautam; Tan, Kwong Huat Benny

2013-01-01

298

Attenuation of Proinflammatory Responses by S-[6]-Gingerol via Inhibition of ROS/NF-Kappa B/COX2 Activation in HuH7 Cells.  

Science.gov (United States)

Introduction. Hepatic inflammation underlies the pathogenesis of chronic diseases such as insulin resistance and type 2 diabetes mellitus. S-[6]-Gingerol has been shown to have anti-inflammatory properties. Important inflammatory mediators of interleukins include nuclear factor ? B (NF ? B) and cyclooxygenase 2 (COX2). We now explore the mechanism of anti-inflammatory effects of S-[6]-gingerol in liver cells. Methods. HuH7 cells were stimulated with IL1? to establish an in vitro hepatic inflammatory model. Results. S-[6]-Gingerol attenuated IL1?-induced inflammation and oxidative stress in HuH7 cells, as evidenced by decreasing mRNA levels of inflammatory factor IL6, IL8, and SAA1, suppression of ROS generation, and increasing mRNA levels of DHCR24. In addition, S-[6]-gingerol reduced IL1?-induced COX2 upregulation as well as NF ? B activity. Similar to the protective effects of S-[6]-gingerol, both NS-398 (a selective COX2 inhibitor) and PDTC (a selective NF ? B inhibitor) suppressed mRNA levels of IL6, IL8, and SAA1. Importantly, PDTC attenuated IL1?-induced overexpression of COX2. Of particular note, the protective effect of S-[6]-gingerol against the IL1?-induced inflammatory response was similar to that of BHT, an ROS scavenger. Conclusions. The findings of this study demonstrate that S-[6]-gingerol protects HuH7 cells against IL1?-induced inflammatory insults through inhibition of the ROS/NF ? B/COX2 pathway. PMID:23843863

Li, Xiao-Hong; McGrath, Kristine C Y; Tran, Van H; Li, Yi-Ming; Duke, Colin C; Roufogalis, Basil D; Heather, Alison K

2013-01-01

299

RAR?-C-Fos-PPAR?2 signaling rather than ROS generation is critical for all-trans retinoic acid-inhibited adipocyte differentiation.  

Science.gov (United States)

Obesity has become a worldwide public health problem, which is mainly determined by excess energy intake and adipose tissue expansion. Adipose tissue expansion can occur through hyperplasia (adipocyte differentiation) or hypertrophy. Retinoic acid was shown to inhibit adipocyte differentiation. However, the molecular mechanism is unclear. In the study, we found that all-trans-retinoic acid (ATRA) inhibited 3T3-L1 adipocyte differentiation. We did not observe significant apoptosis in differentiated adipocytes treated by ATRA. ATRA increased ROS generation and disturbed redox balance. However, antioxidant treatment did not ameliorate the reduction of lipid accumulation induced by ATRA, indicating that ROS generation was not involved in ATRA-inhibited adipocyte differentiation. ATRA reduced C/EBP?, PPAR? and its target gene expression. In the presence of ATRA, retinoic acid receptor (RAR) ?/? expression was increased. Inhibition of RAR?, but not RAR?, blocked ATRA-induced reduction of PPAR?2 expression. ATRA induced a profound interaction between RAR? and C-Fos protein, reflected by Co-IP results. C-Fos was found to exhibit a differentiation-dependent DNA binding activity to PPAR?2 promoter. RAR? inhibitor significantly suppressed ATRA-inhibited DNA binding activity of C-Fos to PPAR?2 promoter, indicating that downregulation of C-Fos activity mediated activation of RAR?-exerted reduction of PPAR?2 expression and thus inhibition of adipocyte differentiation induced by ATRA. Taken together, these data demonstrates that RAR?-C-Fos-PPAR?2 signaling rather than ROS generation is critical for ATRA-inhibited adipocyte differentiation. PMID:25173565

Wang, Xin; Yang, Peng; Liu, Jiangzheng; Wu, Hao; Yu, Weihua; Zhang, Tao; Fu, Han; Liu, Ying; Hai, Chunxu

2014-11-01

300

As a novel p53 direct target, bidirectional gene HspB2/?B-crystallin regulates the ROS level and Warburg effect.  

Science.gov (United States)

Many mammalian genes are composed of bidirectional gene pairs with the two genes separated by less than 1.0kb. The transcriptional regulation and function of these bidirectional genes remain largely unclear. Here, we report that bidirectional gene pair HspB2/?B-crystallin, both of which are members of the small heat shock protein gene family, is a novel direct target gene of p53. Two potential binding sites of p53 are present in the intergenic region of HspB2/?B-crystallin. p53 up-regulated the bidirectional promoter activities of HspB2/?B-crystallin. Actinomycin D (ActD), an activator of p53, induces the promoter and protein activities of HspB2/?B-crystallin. p53 binds to two p53 binding sites in the intergenic region of HspB2/?B-crystallin in vitro and in vivo. Moreover, the products of bidirectional gene pair HspB2/?B-crystallin regulate glucose metabolism, intracellular reactive oxygen species (ROS) level and the Warburg effect by affecting metabolic genes, including the synthesis of cytochrome c oxidase 2 (SCO2), hexokinase II (HK2), and TP53-induced glycolysis and apoptosis regulator (TIGAR). The ROS level and the Warburg effect are affected after the depletion of p53, HspB2 and ?B-crystallin respectively. Finally, we show that both HspB2 and ?B-crystallin are linked with human renal carcinogenesis. These findings provide novel insights into the role of p53 as a regulator of bidirectional gene pair HspB2/?B-crystallin-mediated ROS and the Warburg effect. PMID:24859470

Liu, Shuang; Yan, Bin; Lai, Weiwei; Chen, Ling; Xiao, Desheng; Xi, Sichuan; Jiang, Yiqun; Dong, Xin; An, Jing; Chen, Xiang; Cao, Ya; Tao, Yongguang

2014-07-01

 
 
 
 
301

Statins inhibit hypoxia-induced endothelial proliferation by preventing calcium-induced ROS formation.  

Science.gov (United States)

Pathological hypoxia plays an important role in many diseases, such as atherosclerosis, cancer, and rheumatoid arthritis. The aim of the present study was to examine the effects of different statins on hypoxia-induced endothelial cell signalling. Human umbilical cord vein endothelial cells (HUVEC) were treated with NaCN (CN, 2.5 mmol/l) to simulate a transient hypoxia. The CN-induced increase of endothelial cell numbers was significantly (n = 10, p < 0.01) reduced by the Ca(2+) chelator BAPTA (10 micromol/l), or the reactive oxygen species (ROS) scavenger N-acetylcysteine (ACC, 1 mmol/l), or the NAD(P)H-oxidase inhibitor diphenyleneiodonium (DPI, 5 micromol/l). In detail, cell numbers were (in percentage of control): 163.24 (CN), 90.06 (CN+ACC), 92.06 (CN+DPI). Intracellular-Ca(2+) and -ROS, analysed by fluorescence imaging, were significantly increased by CN. Interestingly, the CN-induced increase of ROS was in part Ca(2+)-dependent, whereas the Ca(2+) increase was not ROS-dependent. Simvastatin (5 micromol/l), fluvastatin (2.5 micromol/l), and cerivastatin (0.1 micromol/l) all reduced CN-induced proliferation, ROS generation and Ca(2+) increase. Cell viability was not reduced by the statins and the antiproliferative effect was completely reversed by mevalonate (500 micromol/l). In conclusion our study demonstrates that statins block hypoxia-associated endothelial proliferation by preventing the increase of Ca(2+) and ROS. PMID:16112121

Schaefer, Christian Alexander; Kuhlmann, Christoph Ruediger Wolfram; Weiterer, Sebastian; Fehsecke, Annett; Abdallah, Yaser; Schaefer, Claudia; Schaefer, Martina Barbara; Mayer, Konstantin; Tillmanns, Harald; Erdogan, Ali

2006-04-01

302

Hyperoxygenation Attenuated a Murine Model of Atopic Dermatitis through Raising Skin Level of ROS  

Science.gov (United States)

Atopic dermatitis (AD) is a chronic inflammatory skin disease resulting from excessive stimulation of immune cells. Traditionally, reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases, but several opposing observations suggest the protective role of ROS in inflammatory disease. Recently, we demonstrated ROS prevented imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function. Thus, we hypothesized AD might also be attenuated in elevated levels of ROS through tissue hyperoxygenation, such as by hyperbaric oxygen therapy (HBOT) or applying an oxygen-carrying chemical, perfluorodecalin (PFD). Elevated levels of ROS in the skin have been demonstrated directly by staining with dihydroethidum as well as indirectly by immunohistochemistry (IHC) for indoleamine 2,3-dioxygenase (IDO). A murine model of AD was developed by repeated application of a chemical irritant (1% 2,4-dinitrochlorobenzene) and house dust mite (Dermatophagoide farinae) extract on one ear of BALB/c mice. The results showed treatment with HBOT or PFD significantly attenuated AD, comparably with 0.1% prednicarbate without any signs of side effects, such as telangiectasia. The expressions of interleukin-17A and interferon-? were also decreased in the AD lesions by treatment with HBOT or PFD. Enhanced expression of IDO and reduced level of hypoxia-inducible factor-1?, in association with increased frequency of FoxP3+ regulatory T cells in the AD lesions, might be involved in the underlying mechanism of oxygen therapy. Taken together, it was suggested that tissue hyperoxygenation, by HBOT or treatment with PFD, might attenuate AD through enhancing skin ROS level. PMID:25275529

Choi, Eun-Jeong; Lee, Yeo Kyong; Kie, Jeong-Hae; Jang, Myoung Ho; Seoh, Ju-Young

2014-01-01

303

Electron spin resonance spectroscopy for the study of nanomaterial-mediated generation of reactive oxygen species.  

Science.gov (United States)

Many of the biological applications and effects of nanomaterials are attributed to their ability to facilitate the generation of reactive oxygen species (ROS). Electron spin resonance (ESR) spectroscopy is a direct and reliable method to identify and quantify free radicals in both chemical and biological environments. In this review, we discuss the use of ESR spectroscopy to study ROS generation mediated by nanomaterials, which have various applications in biological, chemical, and materials science. In addition to introducing the theory of ESR, we present some modifications of the method such as spin trapping and spin labeling, which ultimately aid in the detection of short-lived free radicals. The capability of metal nanoparticles in mediating ROS generation and the related mechanisms are also presented. PMID:24673903

He, Weiwei; Liu, Yitong; Wamer, Wayne G; Yin, Jun-Jie

2014-03-01

304

Icariside II inhibits cell proliferation and induces cell cycle arrest through the ROS-p38-p53 signaling pathway in A375 human melanoma cells.  

Science.gov (United States)

Icariside II (IS) is a metabolite of icariin, which is derived from Herba Epimedii. In the present study, the antiproliferative effects of IS on A375 human melanoma cells were examined in vitro and a possible mechanism through the ROS-p38-p53 pathway is discussed. A cell WST-8 assay revealed that treatment with IS markedly reduced cell viability from 77 to 21% (25 and 100 µM, respectively), and cell counting demonstrated that IS treatment reduced cell proliferation. IS treatment also induced cell cycle arrest of A375 cells at the G0/G1 and G2/M transitions and inhibited the expression of cell-cycle related proteins, including cyclin E, cyclin-dependent kinase 2 (CDK2), cyclin B1 and phosphorylated cyclin-dependent kinase 1 (P-CDK1). In this study, it was determined that IS inhibits cell proliferation and induces cell cycle arrest through the generation of reactive oxygen species and activation of p38 and p53. These findings were further supported by the evidence that pretreatment with N-acetyl-L-cysteine, SB203580 or pifithrin-? significantly blocked IS-induced reduction of cell viability, increase of cell death and cell cycle arrest. In conclusion, IS inhibits cell proliferation and induces cell cycle arrest. Crucially, it was confirmed that these effects were mediated at least in part by activating the ROS-p38-p53 pathway. PMID:25333296

Wu, Jinfeng; Song, Tao; Liu, Shuyong; Li, Xiaomei; Li, Gang; Xu, Jinhua

2015-01-01

305

TGF-{beta}1 increases invasiveness of SW1990 cells through Rac1/ROS/NF-{kappa}B/IL-6/MMP-2  

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} Rac1 mediates TGF-{beta}1-induced SW1990 invasion through MMP-2 secretion and activation. {yields} NADPH-generated ROS act downstream of Rac1 in TGF-{beta}1-challenged SW1990 cells. {yields} TGF-{beta}1-stimulated ROS activate NF-{kappa}B in SW1990 cells. {yields} NF{kappa}B-induced IL-6 release is required for secretion and activation of MMP-2 in SW1990 cells. -- Abstract: Human pancreatic cancer invasion and metastasis have been found to correlate with increased levels of active matrix metalloproteinase 2 (MMP-2). The multifunctional cytokine transforming growth factor beta 1 (TGF-{beta}1) has been shown to increase both secretion of MMP-2 and invasion by several pancreatic cancer cell types. In the present study, we investigated the signaling pathway involved in TGF-{beta}1-promoted MMP-2 secretion and invasion by human pancreatic cancer cells SW1990. Using specific inhibitors, we found that stimulation of these tumor cells with TGF-{beta}1 induced secretion and activation of the collagenase MMP-2, which was required for TGF-{beta}1-stimulated invasion. Our results also indicate that signaling events involved in TGF-{beta}1-enhanced SW1990 invasiveness comprehend activation of Rac1 followed by generation of reactive oxygen species through nicotinamide adenine dinucleotide phosphate-oxidase, activation of nuclear factor-kappa beta, release of interleukin-6, and secretion and activation of MMP-2.

Binker, Marcelo G. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina); Binker-Cosen, Andres A. [CBRHC Research Center, Buenos Aires (Argentina); Gaisano, Herbert Y. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); Cosen, Rodica H. de [CBRHC Research Center, Buenos Aires (Argentina); Cosen-Binker, Laura I., E-mail: laura.cosen.binker@utoronto.ca [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina)

2011-02-04

306

Comparison of on-line and off-line methods to quantify reactive oxygen species (ROS) in atmospheric aerosols  

Science.gov (United States)

Atmospheric aerosol particle concentrations have been linked with a wide range of pulmonary and cardio-vascular diseases but the particle properties responsible for these negative health effects are largely unknown. It is often speculated that reactive oxygen species (ROS) present in atmospheric particles lead to oxidative stress in, and ultimately disease of, the human lung. The quantification of ROS is highly challenging because some ROS components such as radicals are highly reactive and therefore short-lived. Thus, fast analysis methods are likely advantageous over methods with a long delay between aerosol sampling and ROS analysis. We present for the first time a detailed comparison of conventional off-line and fast on-line methods to quantify ROS in organic aerosols. For this comparison a new and fast on-line instrument was built and characterized to quantify ROS in aerosol particles with high sensitivity and a limit of detection of 4 nmol H2O2 equivalents per m3 air. ROS concentrations are measured with a time resolution of approximately 15 min, which allows the tracking of fast changing atmospheric conditions. The comparison of the off-line and on-line method shows that, in oxidized organic model aerosol particles, the majority of ROS have a very short lifetime of a few minutes whereas a small fraction is stable for a day or longer. This indicates that off-line techniques, where there is often a delay of hours to days between particle collection and ROS analysis, may severely underestimate true ROS concentrations and that fast on-line techniques are necessary for a reliable ROS quantification in atmospheric aerosol particles and a meaningful correlation with health outcomes.

Fuller, S. J.; Wragg, F. P. H.; Nutter, J.; Kalberer, M.

2014-08-01

307

Relationship between oxidative stress and hepatic glutathione levels in ethanol-mediated apoptosis of polarized hepatic cells  

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Full Text Available AIM: To investigate the role of reactive oxygen species (ROS in ethanol-mediated cell death of polarized hepatic (WIF-B cells.METHODS: In this work, WIF-B cultures were treated with pyrazole (inducer of cytochrome P4502E1, CYP2E1 and/or L-buthionine sulfoximine (BSO, a known inhibitor of hepatic glutathione (GSH, followed by evaluation of ROS production, antioxidant levels, and measures of cell injury (apoptosis and necrosis.RESULTS: The results revealed that ethanol treatment alone caused a significant two-fold increase in the activation of caspase-3 as well as a similar doubling in ROS. When the activity of the CYP2E1 was increased by pyrazole pretreatment, an additional two-fold elevation in ROS was detected. However, the CYP2E1-related ROS elevation was not accompanied with a correlative increase in apoptotic cell injury, but rather was found to be associated with an increase in necrotic cell death. Interestingly, when the thiol status of the cells was manipulated using BSO, the ethanol-induced activation of caspase-3 was abrogated. Additionally, ethanol-treated cells displayed enhanced susceptibility to Fas-mediated apoptosis that was blocked by GSH depletion as a result of diminished caspase-8 activity.CONCLUSION: Apoptotic cell death induced as a consequence of ethanol metabolism is not completely dependent upon ROS status but is dependent on sustained GSH levels.

Benita L McVicker, Pamela L Tuma, Kusum K Kharbanda, Serene ML Lee, Dean J Tuma

2009-06-01

308

Role of TLR4/NADPH oxidase/ROS-activated p38 MAPK in VCAM-1 expression induced by lipopolysaccharide in human renal mesangial cells  

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Full Text Available Abstract Background In bacteria-induced glomerulonephritis, Toll-like receptor 4 (TLR4 activation by lipopolysaccharide (LPS, a key component of the outer membranes of Gram-negative bacteria can increase oxidative stress and the expression of vascular cell adhesion molecule-1 (VCAM-1, which recruits leukocytes to the glomerular mesangium. However, the mechanisms underlying VCAM-1 expression induced by LPS are still unclear in human renal mesangial cells (HRMCs. Results We demonstrated that LPS induced VCAM-1 mRNA and protein levels associated with an increase in the promoter activity of VCAM-1, determined by Western blot, RT-PCR, and promoter assay. LPS-induced responses were inhibited by transfection with siRNAs of TLR4, myeloid differentiation factor 88 (MyD88, Nox2, Nox4, p47phox, c-Src, p38 MAPK, activating transcription factor 2 (ATF2, and p300 or pretreatment with the inhibitors of reactive oxygen species (ROS, edaravone, NADPH oxidase [apocynin (APO or diphenyleneiodonium chloride (DPI], c-Src (PP1, p38 MAPK (SB202190, and p300 (GR343. LPS induced NADPH oxidase activation, ROS production, and p47phox translocation from the cytosol to the membrane, which were reduced by PP1 or c-Src siRNA. We observed that LPS induced TLR4, MyD88, c-Src, and p47phox complex formation determined by co-immunoprecipitation and Western blot. We further demonstrated that LPS stimulated ATF2 and p300 phosphorylation and complex formation via a c-Src/NADPH oxidase/ROS/p38 MAPK pathway. Up-regulation of VCAM-1 led to enhancing monocyte adhesion to HRMCs challenged with LPS, which was inhibited by siRNAs of c-Src, p47phox, p38 MAPK, ATF2, and p300 or pretreatment with an anti-VCAM-1 neutralizing antibody. Conclusions In HRMCs, LPS-induced VCAM-1 expression was, at least in part, mediated through a TLR4/MyD88/ c-Src/NADPH oxidase/ROS/p38 MAPK-dependent p300 and ATF2 pathway associated with recruitment of monocyte adhesion to kidney. Blockade of these pathways may reduce monocyte adhesion via VCAM-1 suppression and attenuation of the inflammatory responses in renal diseases.

Lee I-Ta

2012-11-01

309

CysLT1 receptor-induced human airway smooth muscle cells proliferation requires ROS generation, EGF receptor transactivation and ERK1/2 phosphorylation  

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Full Text Available Abstract Background Cysteine-containing leukotrienes (cysteinyl-LTs are pivotal inflammatory mediators that play important roles in the pathophysiology of asthma, allergic rhinitis, and other inflammatory conditions. In particular, cysteinyl-LTs exert a variety of effects with relevance to the aetiology of asthma such as smooth muscle contraction, eosinophil recruitment, increased microvascular permeability, enhanced mucus secretion and decreased mucus transport and, finally, airway smooth muscle cells (ASMC proliferation. We used human ASMC (HASMC to identify the signal transduction pathway(s of the leukotriene D4 (LTD4-induced DNA synthesis. Methods Proliferation of primary HASMC was measured by [3H]thymidine incorporation. Phosphorylation of EGF receptor (EGF-R and ERK1/2 was assessed with a polyclonal anti-EGF-R or anti-phosphoERKl/2 monoclonal antibody. A Ras pull-down assay kit was used to evaluate Ras activation. The production of reactive oxygen species (ROS was estimated by measuring dichlorodihydrofluorescein (DCF oxidation. Results We demonstrate that in HASMC LTD4-stimulated thymidine incorporation and potentiation of EGF-induced mitogenic signaling mostly depends upon EGF-R transactivation through the stimulation of CysLT1-R. Accordingly, we found that LTD4 stimulation was able to trigger the increase of Ras-GTP and, in turn, to activate ERK1/2. We show here that EGF-R transactivation was sensitive to pertussis toxin (PTX and phosphoinositide 3-kinase (PI3K inhibitors and that it occurred independently from Src activity, despite the observation of a strong impairment of LTD4-induced DNA synthesis following Src inhibition. More interestingly, CysLT1-R stimulation increased the production of ROS and N-acetylcysteine (NAC abolished LTD4-induced EGF-R phosphorylation and thymidine incorporation. Conclusion Collectively, our data demonstrate that in HASMC LTD4 stimulation of a Gi/o coupled CysLT1-R triggers the transactivation of the EGF-R through the intervention of PI3K and ROS. While PI3K and ROS involvement is an early event, the activation of Src occurs downstream of EGF-R activation and is followed by the classical Ras-ERK1/2 signaling pathway to control G1 progression and cell proliferation.

Capra Valérie

2006-03-01

310

Intracellular ROS Protection Efficiency and Free Radical-Scavenging Activity of Curcumin  

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Curcumin has many pharmaceutical applications, many of which arise from its potent antioxidant properties. The present research examined the antioxidant activities of curcumin in polar solvents by a comparative study using ESR, reduction of ferric iron in aqueous medium and intracellular ROS/toxicity assays. ESR data indicated that the steric hindrance among adjacent big size groups within a galvinoxyl molecule limited the curcumin to scavenge galvinoxyl radicals effectively, while curcumin showed a powerful capacity for scavenging intracellular smaller oxidative molecules such as H2O2, HO•, ROO•. Cell viability and ROS assays demonstrated that curcumin was able to penetrate into the polar medium inside the cells and to protect them against the highly toxic and lethal effects of cumene hydroperoxide. Curcumin also showed good electron-transfer capability, with greater activity than trolox in aqueous solution. Curcumin can readily transfer electron or easily donate H-atom from two phenolic sites to scavenge free radicals. The excellent electron transfer capability of curcumin is because of its unique structure and different functional groups, including a ?-diketone and several ? electrons that have the capacity to conjugate between two phenyl rings. Therfore, since curcumin is inherently a lipophilic compound, because of its superb intracellular ROS scavenging activity, it can be used as an effective antioxidant for ROS protection within the polar cytoplasm. PMID:22016801

Barzegar, Abolfazl; Moosavi-Movahedi, Ali A.

2011-01-01

311

Late ROS accumulation and radiosensitivity in SOD1-overexpressing human glioma cells.  

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This study investigates the hypothesis that CuZn superoxide dismutase (SOD1) overexpression confers radioresistance to human glioma cells by regulating the late accumulation of reactive oxygen species (ROS) and the G(2)/M-checkpoint pathway. U118-9 human glioma cells (wild type, neo vector control, and stably overexpressing SOD1) were irradiated (0-10 Gy) and assayed for cell survival, cellular ROS levels, cell-cycle-phase distributions, and cyclin B1 expression. SOD1-overexpressing cells were radioresistant compared to wild-type (wt) and neo vector control (neo) cells. Irradiated wt and neo cells showed a significant increase (approximately twofold) in DHE fluorescence beginning at 2 days postirradiation, which remained elevated at 8 days postirradiation. Interestingly, the late accumulation of ROS was suppressed in irradiated SOD1-overexpressing cells. The increase in ROS levels was followed by a decrease in cell growth and viability and an increase in the percentage of cells with sub-G(1) DNA content. SOD1 overexpression enhanced radiation-induced G(2) accumulation within 24 h postirradiation, which was accompanied by a decrease in cyclin B1 mRNA and protein levels. These results support the hypothesis that long after radiation exposure a "metabolic redox response" regulates radiosensitivity of human glioma cells. PMID:18790046

Gao, Zhen; Sarsour, Ehab H; Kalen, Amanda L; Li, Ling; Kumar, Maneesh G; Goswami, Prabhat C

2008-12-01

312

Rare-earth atom motions in ROs4Sb12 (R = La, Pr, Nd, Sm)  

International Nuclear Information System (INIS)

High-resolution inelastic x-ray scattering (IXS) was carried out in the filled-skutterudites ROs4Sb12 (R = La, Pr, Nd, Sm). Low-energy rare-earth modes were found in these compounds. They show significant rare-earth dependence, suggesting a correlation with lanthanide contraction. We discuss the relation between the present IXS measurements and reported other experiments.

313

The role of ROS signaling in cross-tolerance: from model to crop  

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Reactive oxygen species (ROS) are key signaling molecules produced in response to biotic and abiotic stresses that trigger a variety of plant defense responses. Cross-tolerance, the enhanced ability of a plant to tolerate multiple stresses, has been suggested to result partly from overlap between ROS signaling mechanisms. Cross-tolerance can manifest itself both as a positive genetic correlation between tolerance to different stresses (inherent cross-tolerance), and as the priming of systemic plant tolerance through previous exposure to another type of stress (induced cross-tolerance). Research in model organisms suggests that cross-tolerance could be used to benefit the agronomy and breeding of crop plants. However, research under field conditions has been scarce and critical issues including the timing, duration, and intensity of a stressor, as well as its interactions with other biotic and abiotic factors, remain to be addressed. Potential applications include the use of chemical stressors to screen for stress-resistant genotypes in breeding programs and the agronomic use of chemical inducers of plant defense for plant protection. Success of these applications will rely on improving our understanding of how ROS signals travel systemically and persist over time, and of how genetic correlations between resistance to ROS, biotic, and abiotic stresses are shaped by cooperative and antagonistic interactions within the underlying signaling pathways. PMID:25566313

Perez, Ilse Barrios; Brown, Patrick J.

2014-01-01

314

Heat stress induces ROS production and histone phosphorylation in celomocytes of Eisenia hortensis  

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Full Text Available The effect of heat stress on celomocytes (leukocytes from Eisenia hortensis was investigated by measuring the production of reactive oxygen species (ROS. After culturing celomocytes at temperatures ranging from 4 °C (control to 44 °C for 3-16 h, ROS levels were measured using a flow cytometric method employing dihydrorhodamine 123 (DHR123 for ROS detection and 7-aminoactinomycin D (7-AAD as a viability stain. Reproducibly we observed significant (p < 0.05 increases in ROS production and decreases in cell viability at temperatures of 28 °C and above. We then examined the effect of heat stress on histone phosphorylation employing antibodies specific for ?H2AX as an indicator of histone modification. Celomocytes were incubated at temperatures ranging between 20 °C to 35 °C for 16 h and antibodies specific for phosphorylated serines in H2AX histones were employed through flow cytometric analysis. Comparing controls to heat-stressed samples using three separate assays reproducibly confirmed significant H2AX phosphorylation (p < 0.05. Collectively, these results emphasize the importance of selecting appropriate temperatures for rearing invertebrates in laboratory-based habitats and for culturing invertebrate cells when conducting in vitro assays in order to minimize oxidative stress. The possible cellular effects of heat stress in soil ecosystems associated with global warming events is also considered.

RA Tumminello

2013-07-01

315

MicroRNA-155 induction by Mycobacterium bovis BCG enhances ROS production through targeting SHIP1.  

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Macrophages play a critical role in the host immune response against mycobacterial infection. Our previous study has demonstrated that microRNA-155 (miR-155), one of the most important small non-coding RNAs in the immune system, promotes oxygen-independent mycobacterial killing in macrophages. However, little is known regarding the role of miR-155 in modulating oxygen-dependent mycobactericidal response in macrophages, including the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). In the present study, we demonstrated that miR-155 was increased in macrophages after Mycobacterium bovis bacille Calmette-Guérin (BCG) infection. Moreover, the BCG-induced upregulation of miR-155 in macrophages was dependent on TLR2, NF-?B and JNK signaling pathways. More importantly, our study explored that miR-155 significantly elevated ROS production in macrophages, although miR-155 had no influence on the inducible nitric oxide synthase (iNOS) expression or nitric oxide (NO) production. In addition, our study demonstrated that miR-155 repressed the expression of src homology 2 (SH2) containing inositol 5-phosphatase1 (SHIP1), and knockdown of SHIP1 greatly increased ROS production in BCG-infected macrophages. Collectively, these data indicate that miR-155 modulates ROS but not RNS production by targeting SHIP1, which may provide a better understanding of the host anti-mycobacterial response. PMID:24937178

Wang, Jinli; Wu, Minhao; Wen, Jinsheng; Yang, Kun; Li, Miao; Zhan, Xiaoxia; Feng, Lianqiang; Li, Meiyu; Huang, Xi

2014-11-01

316

Photocatalytic ROS production and phototoxicity of titanium dioxide nanoparticles is dependent on solar UV radiation spectrum  

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Generation of reactive oxygen species (ROS) by titanium dioxide nanoparticles (nano-TiO2) and its consequent phototoxicity to Daphnia magna were measured under different solar UV radiation spectrum by applying a series of optical filters in a solar simulator. Removing UVB (280-32...

317

Cellular localization of ROS and NO in olive reproductive tissues during flower development  

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Full Text Available Abstract Background Recent studies have shown that reactive oxygen species (ROS and nitric oxide (NO are involved in the signalling processes taking place during the interactions pollen-pistil in several plants. The olive tree (Olea europaea L. is an important crop in Mediterranean countries. It is a dicotyledonous species, with a certain level of self-incompatibility, fertilisation preferentially allogamous, and with an incompatibility system of the gametophytic type not well determined yet. The purpose of the present study was to determine whether relevant ROS and NO are present in the stigmatic surface and other reproductive tissues in the olive over different key developmental stages of the reproductive process. This is a first approach to find out the putative function of these signalling molecules in the regulation of the interaction pollen-stigma. Results The presence of ROS and NO was analyzed in the olive floral organs throughout five developmental stages by using histochemical analysis at light microscopy, as well as different fluorochromes, ROS and NO scavengers and a NO donor by confocal laser scanning microscopy. The "green bud" stage and the period including the end of the "recently opened flower" and the "dehiscent anther" stages displayed higher concentrations of the mentioned chemical species. The stigmatic surface (particularly the papillae and the stigma exudate, the anther tissues and the pollen grains and pollen tubes were the tissues accumulating most ROS and NO. The mature pollen grains emitted NO through the apertural regions and the pollen tubes. In contrast, none of these species were detected in the style or the ovary. Conclusion The results obtained clearly demonstrate that both ROS and NO are produced in the olive reproductive organs in a stage- and tissue- specific manner. The biological significance of the presence of these products may differ between early flowering stages (defence functions and stages where there is an intense interaction between pollen and pistil which may determine the presence of a receptive phase in the stigma. The study confirms the enhanced production of NO by pollen grains and tubes during the receptive phase, and the decrease in the presence of ROS when NO is actively produced.

Alché Juan

2010-02-01

318

Ca2+-sensors and ROS-GC: Interlocked sensory transduction elements: A review  

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Full Text Available From its initial discovery that ROS-GC membrane guanylate cyclase is a mono-modal Ca2+-transduction system linked exclusively with the phototransduction machinery to the successive finding that it embodies a remarkable bimodal Ca2+signaling device, its widened transduction role in the general signaling mechanisms of the sensory neuron cells was envisioned. A theoretical concept was proposed where Ca2+-modulates ROS-GC through its generated cyclic GMP via a nearby cyclic nucleotide gated channel and creates a hyper- or depolarized sate in the neuron membrane (Ca2+ Binding Proteins 1:1, 7-11, 2006. The generated electric potential then becomes a mode of transmission of the parent [Ca2+]i signal. Ca2+ and ROS-GC are interlocked messengers in multiple sensory transduction mechanisms. This comprehensive review discusses the developmental stages to the present status of this concept and demonstrates how neuronal Ca2+-sensor proteins are the interconnected elements of this elegant ROS-GC transduction system. The focus is on the dynamism of the structural composition of this system, and how it accommodates selectivity and elasticity for the Ca2+ signals to perform multiple tasks linked with the SENSES of vision, smell and possibly of taste and the pineal gland. An intriguing illustration is provided for the Ca2+ sensor GCAP1 which displays its remarkable ability for its flexibility in function from being a photoreceptor sensor to an odorant receptor sensor. In doing so it reverses its function from an inhibitor of ROS-GC to the stimulator of ONE-GC membrane guanylate cyclase.

RameshwarKSharma

2012-04-01

319

Prooxidant properties of p66shc are mediated by mitochondria in human cells.  

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p66shc is a protein product of an mRNA isoform of SHC1 gene that has a pro-oxidant and pro-apoptotic activity and is implicated in the aging process. Mitochondria were suggested as a major source of the p66shc-mediated production of reactive oxygen species (ROS), although the underlying mechanisms are poorly understood. We studied effects of p66shc on oxidative stress induced by hydrogen peroxide or by serum deprivation in human colon carcinoma cell line RKO and in diploid human dermal fibroblasts (HDFs). An shRNA-mediated knockdown of p66shc suppressed and an overexpression of a recombinant p66shc stimulated the production of ROS in the both models. This effect was not detected in the mitochondrial DNA-depleted ?0-RKO cells that do not have the mitochondrial electron transport chain (ETC). The p66shc-dependent accumulation of mitochondrial ROS was detected with HyPer-mito, a mitochondria-targeted fluorescent protein sensor for hydrogen peroxide. The fragmentation of mitochondria induced by mitochondrial ROS was significantly reduced in the p66shc deficient RKO cells. Mitochondria-targeted antioxidants SkQ1 and SkQR1 also decreased the oxidative stress induced by hydrogen peroxide or by serum deprivation. Together the data indicate that the p66shc-dependant ROS production during oxidative stress has mitochondrial origin in human normal and cancer cells. PMID:24618848

Galimov, Evgeny R; Chernyak, Boris V; Sidorenko, Alena S; Tereshkova, Alesya V; Chumakov, Peter M

2014-01-01

320

Cypermethrin induces astrocyte damage: role of aberrant Ca(2+), ROS, JNK, P38, matrix metalloproteinase 2 and migration related reelin protein.  

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Cypermethrin is a synthetic type II pyrethroid, derived from a natural pyrethrin of the chrysanthemum plant. Cypermethrin-mediated neurotoxicity is well studied; however, relatively less is known of its effect on astrocyte development and migration. Astrocytes are the major components of blood brain barrier (BBB), and astrocyte damage along with BBB dysfunction impair the tight junction (TJ) proteins resulting in altered cell migration and neurodegeneration. Here, we studied the mechanism of cypermethin mediated rat astrocyte damage and BBB disruption, and determined any change in expression of proteins associated with cell migration. Through MTT assay we found that cypermethrin reduced viability of cultured rat astrocytes. Immunolabelling with astrocyte marker, glial fibrillary acidic protein, revealed alteration in astrocyte morphology. The astrocytes demonstrated an enhanced release of intracellular Ca(++) and ROS, and up-regulation in p-JNK and p-P38 levels in a time-dependent manner. Cypermethrin disrupted the BBB (in vivo) in developing rats and attenuated the expression of the extracellular matrix molecule (ECM) and claudin-5 in cultured astrocytes. We further observed an augmentation in the levels of matrix metalloproteinase 2 (MMP2), known to modulate cellular migration and disrupt the developmental ECM and BBB. We observed an increase in the levels of reelin, involved in cell migration, in cultured rat astrocytes. The reelin receptor, ?3?1integrin, and a mammalian cytosolic protein Disabled1 (Dab1) were also up-regulated. Overall, our study demonstrates that cypermethrin induces astrocyte injury via modulation in Ca(++), ROS, JNK and P38 pathways, which may alter MMP expression and reelin dependent astrocyte migration during brain development. PMID:24861934

Maurya, Shailendra Kumar; Mishra, Juhi; Tripathi, Vinay Kumar; Sharma, Rolee; Siddiqui, Mohammed Haris

2014-05-01

 
 
 
 
321

Onconase induces autophagy sensitizing pancreatic cancer cells to gemcitabine and activates Akt/mTOR pathway in a ROS-dependent manner.  

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Onconase® (ONC) is a member of the RNase super-family that is secreted in oocytes and early embryos of Rana pipiens. Over the last years, research interest about this small and basic frog RNase, also called ranpirnase, constantly increased because of its high cytotoxicity and anticancer properties. Onconase is currently used in clinical trials for cancer therapy; however, the precise mechanisms determining cytotoxicity in cancer cells have not yet been fully investigated. In the present manuscript, we evaluate the antitumoral property of onconase in pancreatic adenocarcinoma cells and in non-tumorigenic cells as a control. We demonstrate that ONC stimulates a strong antiproliferative and proapoptotic effect in cancer cells by reporting for the first time that ONC triggers Beclin1-mediated autophagic cancer cell death. In addition, ONC inhibits the expression of mitochondrial uncoupling protein 2 (UCP2) and of manganese-dependent superoxide dismutase (MnSOD) triggering mitochondrial superoxide ion production. ONC-induced reactive oxygen species (ROS) are responsible for Akt/mTOR pathway stimulation determining the sensitivity of cancer cells to mTOR inhibitors and lessening autophagic stimulation. This indicates ROS/Akt/mTOR axis as a strategy adopted by cancer cells to reduce ONC-mediated cytotoxic autophagy stimulation. In addition, we demonstrate that ONC can sensitize pancreatic cancer cells to the standard chemotherapeutic agent gemcitabine allowing a reduction of drug concentration when used in combination settings, thus suggesting a lowering of chemotherapy-related side effects. Altogether, our results shed more light on the mechanisms lying at the basis of ONC antiproliferative effect in cancer cells and support its potential use to develop new anticancer strategies. PMID:25533084

Fiorini, Claudia; Cordani, Marco; Gotte, Giovanni; Picone, Delia; Donadelli, Massimo

2015-03-01

322

Basal and T?-induced ROS production in lymphocyte mitochondria is increased in type 2 diabetic patients.  

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Mitochondrial function, including production of reactive oxygen species (ROS), is important in the pathogenesis of diabetes and its complications. Thyroid hormones are major regulator of these processes. Hence, the aim of this study was to examine the thyroid hormone regulation of ROS production in human lymphocytes in patients with diabetes mellitus type 2 (T2DM). Lymphocytes from 10 controls and 10 persons with T2DM were examined. Mitochondrial membrane potential (MMP) was examined by flow cytometry after staining with MitoTracker Green (MTG). Similarly ROS was measured following staining with carboxy-H?DCFDA. MMP was increased in T2DM patients and T? stimulation increased MMP in controls [1398 a.u. (979-4094) vs. 2156 a.u. (1611-15189), p=0.04, median and quartiles] as well as in T2DM patients [9167 a.u. (7387-11746) vs. 20274 a.u. (17183-27839 p=0.004, median and quartiles]. Basal ROS concentration was increased in lymphocytes from T2DM and T? significantly stimulated ROS concentration in controls [3691 a.u. (2584-6396) vs. 5650 a.u. (3001-7802) p=0.013, median and quartiles] and in T2DM patients [19271 a.u. (6288-25282) vs. 23178 a.u. (10004-28857) p=0.013, median and quartiles]. The ratio of ROS production related to MMP was significantly higher in T2DM, unstimulated as well as T?-stimulated in T2DM. Unstimulated and T? stimulated ROS production and MMP were higher in lymphocytes from diabetic patients. An altered balance between ROS production and MMP, favoring ROS production in T2DM patients, was found suggesting that an increased mitochondrial sensitivity for T? may be a significant factor responsible for increased ROS activity in diabetic patients. PMID:23015613

Anthonsen, S; Larsen, J; Pedersen, P L; Dalgaard, L T; Kvetny, J

2013-04-01

323

Andrographolide downregulates the v-Src and Bcr-Abl oncoproteins and induces Hsp90 cleavage in the ROS-dependent suppression of cancer malignancy.  

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Andrographolide is a diterpenoid compound isolated from Andrographis paniculata that exhibits anticancer activity. We previously reported that andrographolide suppressed v-Src-mediated cellular transformation by promoting the degradation of Src. In the present study, we demonstrated the involvement of Hsp90 in the andrographolide-mediated inhibition of Src oncogenic activity. Using a proteomics approach, a cleavage fragment of Hsp90? was identified in andrographolide-treated cells. The concentration- and time-dependent induction of Hsp90 cleavage that accompanied the reduction in Src was validated in RK3E cells transformed with either v-Src or a human truncated c-Src variant and treated with andrographolide. In cancer cells, the induction of Hsp90 cleavage by andrographolide and its structural derivatives correlated well with decreased Src levels, the suppression of transformation, and the induction of apoptosis. Moreover, the andrographolide-induced Hsp90 cleavage, Src degradation, inhibition of transformation, and induction of apoptosis were abolished by a ROS inhibitor, N-acetyl-cysteine. Notably, Hsp90 cleavage, decreased levels of Bcr-Abl (another known Hsp90 client protein), and the induction of apoptosis were also observed in human K562 leukemia cells treated with andrographolide or its active derivatives. Together, we demonstrated a novel mechanism by which andrographolide suppressed cancer malignancy that involved inhibiting Hsp90 function and reducing the levels of Hsp90 client proteins. Our results broaden the molecular basis of andrographolide-mediated anticancer activity. PMID:24161787

Liu, Sheng-Hung; Lin, Chao-Hsiung; Liang, Fong-Ping; Chen, Pei-Fen; Kuo, Cheng-Deng; Alam, Mohd Mujahid; Maiti, Barnali; Hung, Shih-Kai; Chi, Chin-Wen; Sun, Chung-Ming; Fu, Shu-Ling

2014-01-15

324

N-acetylcysteine attenuates reactive-oxygen-species-mediated endoplasmic reticulum stress during liver ischemia-reperfusion injury  

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AIM: To investigate the effects of N-acetylcysteine (NAC) on endoplasmic reticulum (ER) stress and tissue injury during liver ischemia reperfusion injury (IRI). METHODS: Mice were injected with NAC (300 mg/kg) intraperitoneally 2 h before ischemia. Real-time polymerase chain reaction and western blotting determined ER stress molecules (GRP78, ATF4 and CHOP). To analyze the role of NAC in reactive oxygen species (ROS)-mediated ER stress and apoptosis, lactate dehydrogenase (LDH) was examined in cultured hepatocytes treated by H2O2 or thapsigargin (TG). RESULTS: NAC treatment significantly reduced the level of ROS and attenuated ROS-induced liver injury after IRI, based on glutathione, malondialdehyde, serum alanine aminotransferase levels, and histopathology. ROS-mediated ER stress was significantly inhibited in NAC-treated mice. In addition, NAC treatment significantly reduced caspase-3 activity and apoptosis after reperfusion, which correlated with the protein expression of Bcl-2 and Bcl-xl. Similarly, NAC treatment significantly inhibited LDH release from hepatocytes treated by H2O2 or TG. CONCLUSION: This study provides new evidence for the protective effects of NAC treatment on hepatocytes during IRI. Through inhibition of ROS-mediated ER stress, NAC may be critical to inhibit the ER-stress-related apoptosis pathway. PMID:25386077

Sun, Yong; Pu, Li-Yong; Lu, Ling; Wang, Xue-Hao; Zhang, Feng; Rao, Jian-Hua

2014-01-01

325

Sensitivity of Malignant Peripheral Nerve Sheath Tumor Cells to TRAIL Is Augmented by Loss of NF1 through Modulation of MYC/MAD and Is Potentiated by Curcumin through Induction of ROS  

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Malignant peripheral nerve sheath tumor (MPNST) is a rare aggressive form of sarcoma often associated with the tumor syndrome neurofibromatosis type 1 (NF1). We investigated the effects of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) on NF1 associated MPNST and determinants of TRAIL sensitivity. MPNST cell lines with complete neurofibromin deficiency were sensitive to apoptotic cell death induced by TRAIL whereas MPNST cells with retained neurofibromin expression or normal human Schwann cells were resistant. Increased sensitivity to TRAIL was associated with overexpression of death receptors, especially DR5. Re-expression of the GAP related domain of neurofibromin (NF1-GRD) suppressed DR5 expression and decreased sensitivity to TRAIL. We show that death receptor expression and TRAIL sensitivity critically depend on c-MYC and that c-MYC amounts are increased by MEK/ERK and PI3K/AKT signalling pathways which are suppressed by neurofibromin. Furthermore PI3K/AKT signalling strongly suppresses the MYC-antagonist MAD1 which significantly contributes to TRAIL sensitivity. Re-expression of the NF1-GRD decreased c-MYC and increased MAD1 amounts suggesting that neurofibromin influences TRAIL sensitivity at least in part by modulating the MYC/MAX/MAD network. The phytochemical curcumin further increased the sensitivity of neurofibromin deficient MPNST cells to TRAIL. This was presumably mediated by ROS, as it correlated with increased ROS production, was blocked by N-acetylcysteine and mimicked by exogenous ROS. PMID:23437333

Reuss, David E.; Mucha, Jana; Hagenlocher, Christian; Ehemann, Volker; Kluwe, Lan; Mautner, Victor; von Deimling, Andreas

2013-01-01

326

Loss of the tumor suppressor Hace1 leads to ROS-dependent glutamine addiction.  

Science.gov (United States)

Cellular transformation is associated with altered glutamine (Gln) metabolism. Tumor cells utilize Gln in the tricarboxylic acid (TCA) cycle to maintain sufficient pools of biosynthetic precursors to support rapid growth and proliferation. However, Gln metabolism also generates NADPH, and Gln-derived glutamate is used for synthesis of glutathione (GSH). As both NADPH and GSH are antioxidants, Gln may also contribute to redox balance in transformed cells. The Hace1 E3 ligase is a tumor suppressor inactivated in diverse human cancers. Hace1 targets the Rac1 GTPase for degradation at Rac1-dependent NADPH oxidase complexes, blocking superoxide generation by the latter. Consequently, loss of Hace1 increases reactive oxygen species (ROS) levels in vitro and in vivo. Given the link between Hace1 loss and increased ROS, we investigated whether genetic inactivation of Hace1 alters Gln metabolism. We demonstrate that mouse embryonic fibroblasts (MEFs) derived from Hace1(-/-) mice are highly sensitive to Gln withdrawal, leading to enhanced cell death compared with wild-type (wt) MEFs, and Gln depletion or chemical inhibition of Gln uptake blocks soft agar colony formation by Hace1(-/-) MEFs. Hace1(-/-) MEFs exhibit increased Gln uptake and ammonia secretion, and metabolic labeling using (13)C-Gln revealed that Hace1 loss increases incorporation of Gln carbons into the TCA cycle intermediates. Gln starvation markedly increases ROS levels in Hace1(-/-) but not in wt MEFs, and treatment with the antioxidant N-acetyl cysteine or the TCA cycle intermediate oxaloacetate efficiently rescues Gln starvation-induced ROS elevation and cell death in Hace1(-/-) MEFs. Finally, Gln starvation increases superoxide levels in Hace1(-/-) MEFs, and NADPH oxidase inhibitors block the induction of superoxide and cell death by Gln starvation. Together, these results suggest that increased ROS production due to Hace1 loss leads to Gln addiction as a mechanism to cope with increased ROS-induced oxidative stress.Oncogene advance online publication, 6 October 2014; doi:10.1038/onc.2014.316. PMID:25284589

Cetinbas, N; Daugaard, M; Mullen, A R; Hajee, S; Rotblat, B; Lopez, A; Li, A; DeBerardinis, R J; Sorensen, P H

2014-10-01

327

ROS-responsive microspheres for on demand antioxidant therapy in a model of diabetic peripheral arterial disease.  

Science.gov (United States)

A new microparticle-based delivery system was synthesized from reactive oxygen species (ROS)-responsive poly(propylene sulfide) (PPS) and tested for "on demand" antioxidant therapy. PPS is hydrophobic but undergoes a phase change to become hydrophilic upon oxidation and thus provides a useful platform for ROS-demanded drug release. This platform was tested for delivery of the promising anti-inflammatory and antioxidant therapeutic molecule curcumin, which is currently limited in use in its free form due to poor pharmacokinetic properties. PPS microspheres efficiently encapsulated curcumin through oil-in-water emulsion and provided sustained, on demand release that was modulated in vitro by hydrogen peroxide concentration. The cytocompatible, curcumin-loaded microspheres preferentially targeted and scavenged intracellular ROS in activated macrophages, reduced in vitro cell death in the presence of cytotoxic levels of ROS, and decreased tissue-level ROS in vivo in the diabetic mouse hind limb ischemia model of peripheral arterial disease. Interestingly, due to the ROS scavenging behavior of PPS, the blank microparticles also showed inherent therapeutic properties that were synergistic with the effects of curcumin in these assays. Functionally, local delivery of curcumin-PPS microspheres accelerated recovery from hind limb ischemia in diabetic mice, as demonstrated using non-invasive imaging techniques. This work demonstrates the potential for PPS microspheres as a generalizable vehicle for ROS-demanded drug release and establishes the utility of this platform for improving local curcumin bioavailability for treatment of chronic inflammatory diseases. PMID:25522975

Poole, Kristin M; Nelson, Christopher E; Joshi, Rucha V; Martin, John R; Gupta, Mukesh K; Haws, Skylar C; Kavanaugh, Taylor E; Skala, Melissa C; Duvall, Craig L

2015-02-01

328

Temporally distinct roles of ATM and ROS in genotoxic stress dependent induction and maintenance of cellular senescence.  

Science.gov (United States)

Cells exposed to genotoxic stress induce cellular senescence through a DNA damage response pathway regulated by ATM kinase and ROS. Here we show that regulatory roles for ATM kinase and ROS differ during induction and maintenance of cellular senescence. Cells treated with different genotoxic agents were analysed using specific pathway markers and inhibitors to determine that ATM kinase activation is directly proportional to the dose of the genotoxic stress and senescence initiation is not dependent on ROS or p53 status of cells. Cells in which ROS was quenched, still activated ATM and initiated DDR when insulted, and progressed normally to senescence. On the other hand, maintenance of viable senescent state needed presence of ROS as well as activated ATM. Inhibition or removal of either of the components caused cell death in senescent cells, through a deregulated ATM-ROS axis. Overall, our work demonstrates existence of intricate temporal hierarchy between genotoxic stress, DDR and ROS in cellular senescence. Our model reports existence of different stages of cellular senescence having distinct regulatory networks. PMID:25416819

Nair, Raji R; Bagheri, Meisam; Saini, Deepak Kumar

2014-11-21

329

Type I cell ROS kinetics under hypoxia in the intact mouse carotid body ex vivo: a FRET-based study.  

Science.gov (United States)

Reactive oxygen species (ROS) mainly originating from NADPH oxidases have been shown to be involved in the carotid body (CB) oxygen-sensing cascade. For measuring ROS kinetics, type I cells of the mouse CB in an ex vivo preparation were transfected with the ROS sensor construct FRET-HSP33. After 2 days of tissue culture, type I cells expressed FRET-HSP33 as shown by immunohistochemistry. In one population of CBs, 5 min of hypoxia induced a significant and reversible decrease of type I cell ROS levels (n = 9 CBs; P < 0.015), which could be inhibited by 4-(2-aminoethyl)benzensulfonylfluorid (AEBSF), a highly specific inhibitor of the NADPH oxidase subunits p47phox and p67phox. In another population of CBs, however, 5 min of hypoxia induced a significant and reversible increase of ROS levels in type I cells (n = 8 CBs; P < 0.05), which was slightly enhanced by administration of 3 mM AEBSF. These different ROS kinetics seemed to coincide with different mice breeding conditions. Type I cells of both populations showed a typical hypoxia-induced membrane potential (MP) depolarization, which could be inhibited by 3 mM AEBSF. ROS and MP closely followed the hypoxic decrease in CB tissue oxygen as measured with an O2-sensitive dye. We conclude that attenuated p47phox subunit activity of the NADPH oxidase under hypoxia is the physiological trigger for type I cell MP depolarization probably due to ROS decrease, whereas the observed ROS increase has no influence on type I cell MP kinetics under hypoxia. PMID:25318107

Bernardini, A; Brockmeier, U; Metzen, E; Berchner-Pfannschmidt, U; Harde, E; Acker-Palmer, A; Papkovsky, D; Acker, H; Fandrey, J

2015-01-01

330

Through time Iberian Ursus spelaeus Ros. Hein. cheek-teeth size distribution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper deals with a metrical comparison of cheek-teeth length of Ursus spelaeus Ros.Hein. Iberian population representatives. Spanish cave bear localities are grouped in four different areas, Torres 1989) which we can tentatively suppose were connected during palaeoenvironmental optimi periods, but were isolated during the most of their existence. It is possible to interpret that the cave bear population was on borrowed time in the Iberian Peninsula, in fact at the species ...

Torres Pe?rez-hidalgo, Trinidad Jose?

2000-01-01

331

Seasonal trends in the composition and ROS activity of fine particulate matter in Baghdad, Iraq  

Science.gov (United States)

Baghdad suffers from severe atmospheric particulate matter (PM) pollution and has limited infrastructure to monitor and control PM-pollution. To help better understand the nature of particulate matter in Baghdad, daily PM2.5 samples were collected every 6th day from September, 2012 to September, 2013. The samples were analyzed for chemical composition and cellular oxidative stress activity using a macrophage-based assay. The annual average PM2.5 concentration was 50 ± 19 ?g m-3, and was comprised of approximately 28% crustal materials, 26% organic carbon (OC), 17% sulfate, 12% elemental carbon (EC), and 8.0% ammonium ion. No clear seasonal trend was observed for the total PM2.5 mass and PM2.5 OC, but EC exhibited higher concentrations in the warmer months, likely due to the extensive use of electric generators operated by diesel and gasoline for cooling. April showed the lowest levels of both EC and OC compared with other months due to both sand and rainstorm events which led to increased deposition and dispersion of local emissions. Concentrations of nitrate ion were low in all seasons due to the high temperatures and low humidity, but slightly higher levels were observed in the cooler months of winter. The oxidative stress (reactive oxygen species (ROS)) activity (59 ± 35 ?g Zymosan equivalents m-3) of the PM was relatively lower than in other studied areas. Association between the water soluble PM constituents and the oxidative activity was investigated using a multi-linear regression model which showed no strong relationships between ROS activity and the water soluble components of PM2.5, but a moderate correlation of water soluble organic carbon from biomass burning (WSOC-BB) was observed (R2 = 0.52). Biomass burning PM has been shown to be an important contributor to ROS activity in other published studies, but additional work is needed to better understand the sources leading to the ROS activity in Baghdad.

Hamad, Samera Hussein; Shafer, Martin Merrill; Kadhim, Ahmed K. H.; Al-Omran, Sabah M.; Schauer, James Jay

2015-01-01

332

Kult?ros ir meno rinka poky?i? visuomen?je  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Šiame tekste aptariama kult?ros ir ekonomikos s?veika, menin?s ir ekonomin?s vert?s skirtumai, meno autonomijos ir komercializavimo dialektika šiuolaikin?je rinkos visuomen?je, parodomojo vartojimo, kult?rinio kapitalo, socialinio statuso svarba šiuolaikin?je meno rinkoje, meno k?rini? kain? nustatymo ir reguliavimo mechanizmai ir meno vartojimo perspektyvos šiuolaikin?je regini? visuomen?je.

Kinc?inaitis, Virginijus

2013-01-01

333

Mitochondrial Genome Instability and ROS Enhance Intestinal Tumorigenesis in APCMin/+ Mice  

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Alterations in mitochondrial oxidative phosphorylation have long been documented in tumors. Other types of mitochondrial dysfunction, including altered reactive oxygen species (ROS) production and apoptosis, also can contribute to tumorigenesis and cancer phenotypes. Furthermore, mutation and altered amounts of mitochondrial DNA (mtDNA) have been observed in cancer cells. However, how mtDNA instability per se contributes to cancer remains largely undetermined. Mitochondrial transcription fact...

Woo, Dong Kyun; Green, Paula D.; Santos, Janine H.; D Souza, Anthony D.; Walther, Zenta; Martin, W. David; Christian, Brooke E.; Chandel, Navdeep S.; Shadel, Gerald S.

2012-01-01

334

ROS homeostasis in halophytes in the context of salinity stress tolerance.  

Science.gov (United States)

Halophytes are defined as plants that are adapted to live in soils containing high concentrations of salt and benefiting from it, and thus represent an ideal model to understand complex physiological and genetic mechanisms of salinity stress tolerance. It is also known that oxidative stress signalling and reactive oxygen species (ROS) detoxification are both essential components of salinity stress tolerance mechanisms. This paper comprehensively reviews the differences in ROS homeostasis between halophytes and glycophytes in an attempt to answer the questions of whether stress-induced ROS production is similar between halophytes and glycophytes; is the superior salinity tolerance in halophytes attributed to higher antioxidant activity; and is there something special about the specific 'pool' of enzymatic and non-enzymatic antioxidants in halophytes. We argue that truly salt-tolerant species possessing efficient mechanisms for Na(+) exclusion from the cytosol may not require a high level of antioxidant activity, as they simply do not allow excessive ROS production in the first instance. We also suggest that H2O2 'signatures' may operate in plant signalling networks, in addition to well-known cytosolic calcium 'signatures'. According to the suggested concept, the intrinsically higher superoxide dismutase (SOD) levels in halophytes are required for rapid induction of the H2O2 'signature', and to trigger a cascade of adaptive responses (both genetic and physiological), while the role of other enzymatic antioxidants may be in decreasing the basal levels of H2O2, once the signalling has been processed. Finally, we emphasize the importance of non-enzymatic antioxidants as the only effective means to prevent detrimental effects of hydroxyl radicals on cellular structures. PMID:24368505

Bose, Jayakumar; Rodrigo-Moreno, Ana; Shabala, Sergey

2014-03-01

335

Carbon black nanoparticles promote endothelial activation and lipid accumulation in macrophages independently of intracellular ROS production.  

Science.gov (United States)

Exposure to nanoparticles (NPs) may cause vascular effects including endothelial dysfunction and foam cell formation, with oxidative stress and inflammation as supposed central mechanisms. We investigated oxidative stress, endothelial dysfunction and lipid accumulation caused by nano-sized carbon black (CB) exposure in cultured human umbilical vein endothelial cells (HUVECs), THP-1 (monocytes) and THP-1 derived macrophages (THP-1a). The proliferation of HUVECs or co-cultures of HUVECs and THP-1 cells were unaffected by CB exposure, whereas there was increased cytotoxicity, assessed by the LDH and WST-1 assays, especially in THP-1 and THP-1a cells. The CB exposure decreased the glutathione (GSH) content in THP-1 and THP-1a cells, whereas GSH was increased in HUVECs. The reactive oxygen species (ROS) production was increased in all cell types after CB exposure. A reduction of the intracellular GSH concentration by buthionine sulfoximine (BSO) pre-treatment further increased the CB-induced ROS production in THP-1 cells and HUVECs. The expression of adhesion molecules ICAM-1 and VCAM-1, but not adhesion of THP-1 to HUVECs or culture dishes, was elevated by CB exposure, whereas these effects were unaffected by BSO pre-treatment. qRT-PCR showed increased VCAM1 expression, but no change in GCLM and HMOX1 expression in CB-exposed HUVECs. Pre-exposure to CB induced lipid accumulation in THP-1a cells, which was not affected by the presence of the antioxidant N-acetylcysteine. In addition, the concentrations of CB to induce lipid accumulation were lower than the concentrations to promote intracellular ROS production in THP-1a cells. In conclusion, exposure to nano-sized CB induced endothelial dysfunction and foam cell formation, which was not dependent on intracellular ROS production. PMID:25184212

Cao, Yi; Roursgaard, Martin; Danielsen, Pernille Høgh; Møller, Peter; Loft, Steffen

2014-01-01

336

Cellular localization of ROS and NO in olive reproductive tissues during flower development  

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Abstract Background Recent studies have shown that reactive oxygen species (ROS) and nitric oxide (NO) are involved in the signalling processes taking place during the interactions pollen-pistil in several plants. The olive tree (Olea europaea L.) is an important crop in Mediterranean countries. It is a dicotyledonous species, with a certain level of self-incompatibility, fertilisation preferentially allogamous, and with an incompatibility system of the gametophytic ...

Alché Juan; Rodríguez-García María; Zafra Adoración

2010-01-01

337

ROS and RNS Signaling in Heart Disorders: Could Antioxidant Treatment Be Successful?  

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There is not too much success in the antioxidant treatment of heart deceases in humans. However a new approach is now developed that suggests that depending on their structures and concentrations antioxidants can exhibit much more complicated functions in many pathological disorders. It is now well established that physiological free radicals superoxide and nitric oxide together with their derivatives hydrogen peroxide and peroxynitrite (all are named reactive oxygen species (ROS) and reactiv...

Igor Afanas'ev

2011-01-01

338

Cryopreservation affects ROS-induced oxidative stress and antioxidant response in Arabidopsis seedlings.  

Science.gov (United States)

Plant recovery status after cryopreservation by vitrification had a negative relationship to the oxidative stress induced by reactive oxygen species (ROS). Arabidopsis thaliana seedlings germinated for 48h or 72h with different survival tolerances were examined at five steps of cryopreservation, to determine the role of ROS (O2(-), H2O2 and OH) and antioxidant systems (SOD, POD, CAT, AsA and GSH) in cryo-injury. In addition, the effects of the steps on membrane lipid peroxidation were studied using malondialdehyde (MDA) as an indicator. The results indicated that H2O2-induced oxidative stress at the steps of dehydration and rapid warming was the main cause of cryo-injury of 48-h seedlings (high survival rate) and 72-h seedlings (no survival). The H2O2 was mainly generated in cotyledons, shoot tips and roots of seedlings as indicated by Amplex Red staining. Low survival of 72-h seedlings was associated with severe membrane lipid peroxidation, which was caused by increased OH generation activity and decreased SOD activity. The antioxidant-related gene expression by qRT-PCR and physiological assays suggested that the antioxidant system of 48-h seedlings were activated by ROS, and they mounted a defense against oxidative stress. A high level of ROS led to the weakening of the antioxidant system of 72-h seedlings. Correlation analysis indicated that enhanced antioxidant enzymes activities contributed to the high survival rate of 48-h seedlings, which could reflect by cryopreservation of antioxidant mutant seedlings. This model system indicated that elevated CAT activity and AsA content were determinants of cryogenic stress tolerance, whose manipulation could improve the recovery of seedlings after cryopreservation. PMID:25489814

Chen, Guan-Qun; Ren, Li; Zhang, Jie; Reed, Barbara M; Zhang, Di; Shen, Xiao-Hui

2015-02-01

339

Intracellular ROS Protection Efficiency and Free Radical-Scavenging Activity of Curcumin  

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Curcumin has many pharmaceutical applications, many of which arise from its potent antioxidant properties. The present research examined the antioxidant activities of curcumin in polar solvents by a comparative study using ESR, reduction of ferric iron in aqueous medium and intracellular ROS/toxicity assays. ESR data indicated that the steric hindrance among adjacent big size groups within a galvinoxyl molecule limited the curcumin to scavenge galvinoxyl radicals effectively, while curcumin s...

Barzegar, Abolfazl; Moosavi-movahedi, Ali A.

2011-01-01

340

Carbon black nanoparticles promote endothelial activation and lipid accumulation in macrophages independently of intracellular ROS production  

DEFF Research Database (Denmark)

Exposure to nanoparticles (NPs) may cause vascular effects including endothelial dysfunction and foam cell formation, with oxidative stress and inflammation as supposed central mechanisms. We investigated oxidative stress, endothelial dysfunction and lipid accumulation caused by nano-sized carbon black (CB) exposure in cultured human umbilical vein endothelial cells (HUVECs), THP-1 (monocytes) and THP-1 derived macrophages (THP-1a). The proliferation of HUVECs or co-cultures of HUVECs and THP-1 cells were unaffected by CB exposure, whereas there was increased cytotoxicity, assessed by the LDH and WST-1 assays, especially in THP-1 and THP-1a cells. The CB exposure decreased the glutathione (GSH) content in THP-1 and THP-1a cells, whereas GSH was increased in HUVECs. The reactive oxygen species (ROS) production was increased in all cell types after CB exposure. A reduction of the intracellular GSH concentration by buthionine sulfoximine (BSO) pre-treatment further increased the CB-induced ROS production in THP-1 cells and HUVECs. The expression of adhesion molecules ICAM-1 and VCAM-1, but not adhesion of THP-1 to HUVECs or culture dishes, was elevated by CB exposure, whereas these effects were unaffected by BSO pre-treatment. qRT-PCR showed increased VCAM1 expression, but no change in GCLM and HMOX1 expression in CB-exposed HUVECs. Pre-exposure to CB induced lipid accumulation in THP-1a cells, which was not affected by the presence of the antioxidant N-acetylcysteine. In addition, the concentrations of CB to induce lipid accumulation were lower than the concentrations to promote intracellular ROS production in THP-1a cells. In conclusion, exposure to nano-sized CB induced endothelial dysfunction and foam cell formation, which was not dependent on intracellular ROS production.

Cao, Yi; Roursgaard, Martin

2014-01-01

 
 
 
 
341

Macrophage CGI-58 Deficiency Activates ROS-Inflammasome Pathway to Promote Insulin Resistance in Mice  

Directory of Open Access Journals (Sweden)

Full Text Available Overnutrition activates a proinflammatory program in macrophages to induce insulin resistance (IR, but its molecular mechanisms remain incompletely understood. Here, we show that saturated fatty acid and lipopolysaccharide, two factors implicated in high-fat diet (HFD-induced IR, suppress macrophage CGI-58 expression. Macrophage-specific CGI-58 knockout (MaKO in mice aggravates HFD-induced glucose intolerance and IR, which is associated with augmented systemic/tissue inflammation and proinflammatory activation of adipose tissue macrophages. CGI-58-deficient macrophages exhibit mitochondrial dysfunction due to defective peroxisome proliferator-activated receptor (PPAR? signaling. Consequently, they overproduce reactive oxygen species (ROS to potentiate secretion of proinflammatory cytokines by activating NLRP3 inflammasome. Anti-ROS treatment or NLRP3 silencing prevents CGI-58-deficient macrophages from oversecreting proinflammatory cytokines and from inducing proinflammatory signaling and IR in the cocultured fat slices. Anti-ROS treatment also prevents exacerbation of inflammation and IR in HFD-fed MaKO mice. Our data thus establish CGI-58 as a suppressor of overnutrition-induced NLRP3 inflammasome activation in macrophages.

Hongming Miao

2014-04-01

342

Influence of thiol stress on oxidative phosphorylation and generation of ROS in Streptomyces coelicolor  

Directory of Open Access Journals (Sweden)

Full Text Available Thiols play very important role in the intracellular redox homeostasis. Imbalance in the redox status leads to changes in the intracellular metabolism including respiration. Thiol stress, a reductive type of stress can also cause redox imbalance. When Gram-positive bacterium Strep- tomyces coelicolor was exposed to thiol stress, catalaseA was induced. Induction of catalaseA is the consequence of elevation of ROS (reactive oxygen species. The two major sources of reactive oxygen species are Fenton reaction and slippage of electrons from electron transport chain during respiration. Hence, the effect of thiol stress was checked on the rate of oxidative phosphorylation in S. coelicolor. We found correlation in the increase of oxidative phosphorylation rate and the generation of ROS, subsequently leading to induction of catalase. It was observed that thiol stress does not affect the functionality of the individual complexes of the ETC, but still there was an increase in the overall respiration, which may lead to generation of more ROS leading to induction of catalase.

Hemendra J. Vekaria

2010-11-01

343

The beetroot component betanin modulates ROS production, DNA damage and apoptosis in human polymorphonuclear neutrophils.  

Science.gov (United States)

The aim of this study was to evaluate the effect of betanin, one of the beetroot major components, on ROS production, DNA damage and apoptosis in human resting and stimulated with phorbol 12-myristate13-acetate polymorphonuclear neutrophils, one of the key elements of the inflammatory response. Incubation of neutrophils with betanin in the concentration range 2-500?µM resulted in significant inhibition of ROS production (by 15-46%, depending on the ROS detection assay). The antioxidant capacity of betanin was most prominently expressed in the chemiluminescence measurements. This compound decreased also the percentage of DNA in comet tails in stimulated neutrophils, but only at the 24?h time point. In resting neutrophils an increased level of DNA in comet tails was observed. Betanin did not affect the activity of caspase-3, in resting neutrophils, but significantly enhanced the enzyme activity in stimulated neutrophils. The western blot analysis showed, however, an increased level of caspase-3 cleavage products as a result of betanin treatment both in resting and stimulated neutrophils. The results indicate that betanin may be responsible for the effect of beetroot products on neutrophil oxidative metabolism and its consequences, DNA damage and apoptosis. The dose and time dependent effects on these processes require further studies. PMID:22076941

Zieli?ska-Przyjemska, Ma?gorzata; Olejnik, Anna; Kostrzewa, Artur; ?uczak, Micha?; Jagodzi?ski, Pawe? P; Baer-Dubowska, Wanda

2012-06-01

344

Reducing mitochondrial ROS improves disease-related pathology in a mouse model of ataxia-telangiectasia.  

Science.gov (United States)

The disease ataxia-telangiectasia (A-T) has no cure and few treatment options. It is caused by mutations in the ATM kinase, which functions in the DNA-damage response and redox sensing. In addition to severe cerebellar degeneration, A-T pathology includes cancer predisposition, sterility, immune system dysfunction, and bone marrow abnormalities. These latter phenotypes are recapitulated in the ATM null (ATM(-/-)) mouse model of the disease. Since oxidative stress and mitochondrial dysfunction are implicated in A-T, we determined whether reducing mitochondrial reactive oxygen species (ROS) via overexpression of catalase targeted to mitochondria (mCAT) alleviates A-T-related pathology in ATM(-/-) mice. We found that mCAT has many beneficial effects in this context, including reduced propensity to develop thymic lymphoma, improved bone marrow hematopoiesis and macrophage differentiation in vitro, and partial rescue of memory T-cell developmental defects. Our results suggest that positive effects observed on cancer development may be linked to mCAT reducing mitochondrial ROS, lactate production, and TORC1 signaling in transforming double-positive cells, whereas beneficial effects in memory T cells appear to be TORC1-independent. Altogether, this study provides proof-of-principle that reducing mitochondrial ROS production per se may be therapeutic for the disease, which may have advantages compared with more general antioxidant strategies. PMID:23011031

D'Souza, Anthony D; Parish, Ian A; Krause, Diane S; Kaech, Susan M; Shadel, Gerald S

2013-01-01

345

Enhanced Th17 differentiation and aggravated arthritis in IEX-1-deficient mice by mitochondrial ROS-mediated signaling  

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CD4+ T helper (Th)1 and Th17 cells both can cause autoimmune diseases either alone or collaboratively, if left unchecked. However, what determines the dominant Th effector phenotype in a specific autoimmune disease remains ill understood. Our present investigation shows that null mutation of immediate early response gene X-1 (IEX-1) promotes differentiation of Th17 cells, but compromising the survival of Th1 cells. The differential effect gave rise to a greater number of Th17 cells, a higher ...

Zhi, Liang; Ustyugova, Irina V.; Chen, Xinyuan; Zhang, Qi; Wu, Mei X.

2012-01-01

346

Using copper ions to amplify ROS-mediated fluorescence for continuous online monitoring of extracellular glucose in living rat brain.  

Science.gov (United States)

In this study we developed a facile and sensitive method for continuous monitoring of extracellular glucose concentration in living rat brain through microdialysis (MD) sampling in conjunction with (i) online sample derivatization using glucose oxidase to generate H2O2, which converted a reactive oxygen species-responsive fluorescent dye, 2',7'-dichlorodihydrofluorescein (DCFH), into fluorescent species, and (ii) a novel non-immobilized enzyme-based fluorescence assay strategy, featuring copper ion (Cu(2+))-facilitated amplification of the fluorescence intensity. After evaluating the experimental conditions for glucose oxidation and fluorescence generation, the introduction of Cu(2+) ions to this system resulted in an additional 51-fold amplification of the net fluorescence intensity. By sequentially loading brain microdialysate into the dual sample collection loops, the sampling frequency was 7.5h(-1). Based on a 40-?L sample volume, the system's detection limit reached as low as 0.18 mM, sufficiently accurate to determine the extracellular glucose concentrations in living rat brains. To demonstrate the proposed system's practical performance and applicability, we conducted (i) spike analyses of biomolecule-rich fetal bovine serum sample, confirming that the analytical reliability was similar to that of a commercial glucose kit, and (ii) in vivo dynamic monitoring of the extracellular glucose concentrations in living rat brains after inducing neural depolarization by perfusing a high-K(+) medium from the MD probe. PMID:25310485

Su, Cheng-Kuan; Chen, Chen-Yu; Tseng, Po-Jen; Sun, Yuh-Chang

2015-02-15

347

Akt downregulation by flavin oxidase–induced ROS generation mediates dose-dependent endothelial cell damage elicited by natural antioxidants  

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High intake of natural antioxidants (NA) from plant-derived foods and beverages is thought to provide cardiovascular benefits. The endothelium plays a pivotal role in cardiovascular homeostasis, and for this reason, the molecular events resulting from NA actions on endothelial cells (ECs) are actively investigated. Here, we show the direct impact of two NA, coumaric acid and resveratrol, on intracellular reactive oxygen species levels, protein carbonylation, and cell physiology in human ECs. ...

Pasciu, Valeria; Posadino, Anna Maria; Cossu, Annalisa; Sanna, Bastiano; Tadolini, Bruna; Gaspa, Leonardo; Marchisio, Andrea; Dessole, Salvatore; Capobianco, Giampiero; Pintus, Gianfranco

2010-01-01

348

Mentha piperita essential oil induces apoptosis in yeast associated with both cytosolic and mitochondrial ROS-mediated damage.  

Science.gov (United States)

Mentha piperita (MP), also known as peppermint, is an aromatic and medicinal plant widely used in the food industry, perfumery and cosmetic, pharmacy and traditional medicine. Its essential oil (EO) displays antimicrobial activity against a range of bacteria and fungi. In this study, we found that MP EO lethal cytotoxicity is associated with increased levels of intracellular reactive oxygen species, mitochondrial fragmentation and chromatin condensation, without loss of the plasma membrane integrity, indicative of an apoptotic process. Overexpression of cytosolic catalase and superoxide dismutases reverted the lethal effects of the EO and of its major component menthol. Conversely, deficiency in Sod1p (cytosolic copper-zinc-superoxide dismutase) greatly increased sensitivity to both agents, but deficiency in Sod2p (mitochondrial manganese superoxide dismutase) only induced sensitivity under respiratory growth conditions. Mentha piperita EO increased the frequency of respiratory deficient mutants indicative of damage to the mitochondrial genome, although increase in mitochondrial thiol oxidation does not seem to be involved in the EO toxicity. PMID:25065265

Ferreira, Patrícia; Cardoso, Teresa; Ferreira, Filipa; Fernandes-Ferreira, Manuel; Piper, Peter; Sousa, Maria João

2014-11-01

349

Natural triterpenic diols promote apoptosis in astrocytoma cells through ROS-mediated mitochondrial depolarization and JNK activation  

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[Principal Findings]: Erythrodiol and uvaol effectively affected cell proliferation, as well as cell cycle phases and induced 1321N1 cell death. Both triterpenes successfully modulated the apoptotic response, promoting nuclear condensation and fragmentation. They caused retraction and rounding of cultured cells, which lost adherence from their supports, while F-actin and vimentin filaments disappeared as an organized cytoplasmic network. At molecular level, changes in the expression of surfac...

Marti?n, Rube?n; Ibeas, Elvira; Carvalho-tavares, Juliana; Herna?ndez, Marita; Ruiz-gutie?rrez, Valentina; Nieto, Mari?a Luisa

2009-01-01

350

Lead-zinc interactions in the production of osteocalcin by ROS 17/2.8 osteoblastic bone cells  

International Nuclear Information System (INIS)

The serum level of osteocalcin, a bone specific protein produced by osteoblasts and used clinically as a marker of osteoblast acceptive, is decreased in lead intoxicated children. Previous studies suggest that the reduced osteocalcin production appears to be the result of impaired transcriptional regulation of this 1,25-dihydroxyvitamin D3 gene product, and not translation. As part of a study to investigate the potential interaction of Pb2+ with Zn2+, and with the zinc fingers of the vitamin D receptor, ROS cells were treated with 0, 5, 10, or 25 ?M lead acetate for 24 hr, in the presence of 10, 30, or 50 ?M Zn followed by an additional 24 hr treatment with lead with 1,25-dihydroxyvitamin D3 (100 pg/ml media). At the end of this period a radioimmunoassay was conducted to determine the amount of osteocalcin in the cells and secreted in the media. 1,25-dihydroxyvitamin D3 caused an increase in osteocalcin secreted into the media in cultures containing 0 ?M lead, but this increase was inhibited by lead in a concentration dependent manner, so that osteocalcin secretion in 10 or 25 ?M lead treated groups was less than cultures without 1,25-dihydroxyvitamin D3 treatment. This inhibitory effect of lead was blocked by increasing the medium zinc concentration of 50 ?M. Increasing medium Pb2+ concentrations decreased the amount of 65Zn taken up by cells by ?30%, which was nullified bylls by ?30%, which was nullified by increasing medium Zn. These results suggest that lead produces a localized and specific Zn deficiency in the vitamin D receptor zinc finger, and perhaps other zinc metalloproteins, and that these effects of lead are not mediated through general effects on RNA or protein synthesis

351

Antibody-induced nonapoptotic cell death in human lymphoma and leukemia cells is mediated through a novel reactive oxygen species-dependent pathway.  

Science.gov (United States)

Monoclonal antibodies (mAbs) have revolutionized the treatment of B-cell malignancies. Although Fc-dependent mechanisms of mAb-mediated tumor clearance have been extensively studied, the ability of mAbs to directly evoke programmed cell death (PCD) in the target cell and the underlying mechanisms involved remain under-investigated. We recently demonstrated that certain mAbs (type II anti-CD20 and anti-HLA DR mAbs) potently evoked PCD through an actin-dependent, lysosome-mediated process. Here, we reveal that the induction of PCD by these mAbs, including the type II anti-CD20 mAb GA101 (obinutuzumab), directly correlates with their ability to produce reactive oxygen species (ROS) in human B-lymphoma cell lines and primary B-cell chronic lymphocytic leukemia cells. ROS scavengers abrogated mAb-induced PCD indicating that ROS are required for the execution of cell death. ROS were generated downstream of mAb-induced actin cytoskeletal reorganization and lysosome membrane permeabilization. ROS production was independent of mitochondria and unaffected by BCL-2 overexpression. Instead, ROS generation was mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. These findings provide further insights into a previously unrecognized role for NADPH oxidase-derived ROS in mediating nonapoptotic PCD evoked by mAbs in B-cell malignancies. This newly characterized cell death pathway may potentially be exploited to eliminate malignant cells, which are refractory to conventional chemotherapy and immunotherapy. PMID:22354003

Honeychurch, Jamie; Alduaij, Waleed; Azizyan, Mahsa; Cheadle, Eleanor J; Pelicano, Helene; Ivanov, Andrei; Huang, Peng; Cragg, Mark S; Illidge, Tim M

2012-04-12

352

MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells  

International Nuclear Information System (INIS)

Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

353

MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells  

Energy Technology Data Exchange (ETDEWEB)

Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells.

Yu, Teng, E-mail: tengyu33@yahoo.com [Department of Dermatology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China); Ji, Jiang [Department of Dermatology, The Second Hospital Affiliated of Soochow University, SuZhou, Jiangsu Province 215000 (China); Guo, Yong-li [Department of Oncology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China)

2013-11-08

354

Hydrogen peroxide mediates interleukin-1ß-induced AP-1 activation in articular chondrocytes: Implications for the regulation of iNOS expression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The pro-inflammatory cytokine interleukin-1ß (IL-1) induces articular chondrocytes to produce reactive oxygen species (ROS), including hydrogen peroxide (H2O2), which mediate some IL-1-induced responses. This study aimed at elucidating the role of ROS, particularly H2O2, in mediating IL-1-induced activation of the transcription factor activator protein-1 (AP-1) in primary cultures of articular chondrocytes. AP-1 may function either as an inducer or as a repressor of the inducible nitric oxid...

Mendes, A. Ferreira; Caramona, M. M.; Carvalho, A. P.; Lopes, M. C.

2003-01-01

355

SIRT3 is a Mitochondrial Tumor Suppressor: A Scientific Tale that Connects Aberrant Cellular ROS, the Warburg Effect, and Carcinogenesis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tumors exhibit metabolic reprogramming characterized by increased cellular reactive oxygen species (ROS) and the preferential use of glucose, as first published by Otto Warburg in 1956, referred to as the “Warburg effect.” However, the mechanism(s) linking these processes remain largely elusive. Murine tumors lacking Sirt3 exhibit abnormally high levels of ROS that directly induce genomic instability and increase HIF-1? protein levels. The subsequent transcription of HIF?-dependent targ...

Haigis, Marcia C.; Deng, Chu-xia; Finley, Lydia W. S.; Kim, Hyun-seok; Gius, David

2012-01-01

356

Generation of reactive oxygen species (ROS) is a key factor for stimulation of macrophage proliferation by ceramide 1-phosphate  

International Nuclear Information System (INIS)

We previously demonstrated that ceramide 1-phosphate (C1P) is mitogenic for fibroblasts and macrophages. However, the mechanisms involved in this action were only partially described. Here, we demonstrate that C1P stimulates reactive oxygen species (ROS) formation in primary bone marrow-derived macrophages, and that ROS are required for the mitogenic effect of C1P. ROS production was dependent upon prior activation of NADPH oxidase by C1P, which was determined by measuring phosphorylation of the p40phox subunit and translocation of p47phox from the cytosol to the plasma membrane. In addition, C1P activated cytosolic calcium-dependent phospholipase A2 and protein kinase C-?, and NADPH oxidase activation was blocked by selective inhibitors of these enzymes. These inhibitors, and inhibitors of ROS production, blocked the mitogenic effect of C1P. By using BHNB-C1P (a photolabile caged-C1P analog), we demonstrate that all of these C1P actions are caused by intracellular C1P. It can be concluded that the enzyme responsible for C1P-stimulated ROS generation in bone marrow-derived macrophages is NADPH oxidase, and that this enzyme is downstream of PKC-? and cPLA2-? in this pathway. -- Highlights: ? Ceramide 1-phosphate (C1P) stimulates reactive oxygen species (ROS) formation. ? The enzyme responsible for ROS generation by C1P in macrophages is NADPH oxidase. ? NADPH oxidase lies downstream of cPLA2-? and PKC-? in this pathway. ? ROS generation is essential for the stimulation of macrophage proliferation by C1P.

357

Mitochondrial depolarization underlies delay in permeability transition by preconditioning with isoflurane: roles of ROS and Ca2+.  

Science.gov (United States)

During reperfusion, the interplay between excess reactive oxygen species (ROS) production, mitochondrial Ca(2+) overload, and mitochondrial permeability transition pore (mPTP) opening, as the crucial mechanism of cardiomyocyte injury, remains intriguing. Here, we investigated whether an induction of a partial decrease in mitochondrial membrane potential (DeltaPsi(m)) is an underlying mechanism of protection by anesthetic-induced preconditioning (APC) with isoflurane, specifically addressing the interplay between ROS, Ca(2+), and mPTP opening. The magnitude of APC-induced decrease in DeltaPsi(m) was mimicked with the protonophore 2,4-dinitrophenol (DNP), and the addition of pyruvate was used to reverse APC- and DNP-induced decrease in DeltaPsi(m). In cardiomyocytes, DeltaPsi(m), ROS, mPTP opening, and cytosolic and mitochondrial Ca(2+) were measured using confocal microscope, and cardiomyocyte survival was assessed by Trypan blue exclusion. In isolated cardiac mitochondria, antimycin A-induced ROS production and Ca(2+) uptake were determined spectrofluorometrically. In cells exposed to oxidative stress, APC and DNP increased cell survival, delayed mPTP opening, and attenuated ROS production, which was reversed by mitochondrial repolarization with pyruvate. In isolated mitochondria, depolarization by APC and DNP attenuated ROS production, but not Ca(2+) uptake. However, in stressed cardiomyocytes, a similar decrease in DeltaPsi(m) attenuated both cytosolic and mitochondrial Ca(2+) accumulation. In conclusion, a partial decrease in DeltaPsi(m) underlies cardioprotective effects of APC by attenuating excess ROS production, resulting in a delay in mPTP opening and an increase in cell survival. Such decrease in DeltaPsi(m) primarily attenuates mitochondrial ROS production, with consequential decrease in mitochondrial Ca(2+) uptake. PMID:20519447

Sedlic, Filip; Sepac, Ana; Pravdic, Danijel; Camara, Amadou K S; Bienengraeber, Martin; Brzezinska, Anna K; Wakatsuki, Tetsuro; Bosnjak, Zeljko J

2010-08-01

358

Toward real-time regional earthquake simulation II: Real-time Online earthquake Simulation (ROS) of Taiwan earthquakes  

Science.gov (United States)

We developed a Real-time Online earthquake Simulation system (ROS) to simulate regional earthquakes in Taiwan. The ROS uses a centroid moment tensor solution of seismic events from a Real-time Moment Tensor monitoring system (RMT), which provides all the point source parameters including the event origin time, hypocentral location, moment magnitude and focal mechanism within 2 min after the occurrence of an earthquake. Then, all of the source parameters are automatically forwarded to the ROS to perform an earthquake simulation, which is based on a spectral-element method (SEM). A new island-wide, high resolution SEM mesh model is developed for the whole Taiwan in this study. We have improved SEM mesh quality by introducing a thin high-resolution mesh layer near the surface to accommodate steep and rapidly varying topography. The mesh for the shallow sedimentary basin is adjusted to reflect its complex geometry and sharp lateral velocity contrasts. The grid resolution at the surface is about 545 m, which is sufficient to resolve topography and tomography data for simulations accurate up to 1.0 Hz. The ROS is also an infrastructural service, making online earthquake simulation feasible. Users can conduct their own earthquake simulation by providing a set of source parameters through the ROS webpage. For visualization, a ShakeMovie and ShakeMap are produced during the simulation. The time needed for one event is roughly 3 min for a 70 s ground motion simulation. The ROS is operated online at the Institute of Earth Sciences, Academia Sinica (http://ros.earth.sinica.edu.tw/). Our long-term goal for the ROS system is to contribute to public earth science outreach and to realize seismic ground motion prediction in real-time.

Lee, Shiann-Jong; Liu, Qinya; Tromp, Jeroen; Komatitsch, Dimitri; Liang, Wen-Tzong; Huang, Bor-Shouh

2014-06-01

359

Expression of glutathione peroxidase 1 in the spheno-occipital synchondrosis and its role in ROS-induced apoptosis.  

Science.gov (United States)

Summary BACKGROUND/OBJECTIVE : Chondrogenesis is an integral part of endochondral bone formation, by which the midline cranial base is developed. Reactive oxygen species (ROS) are required in chondrogenic differentiation and antioxidant enzymes regulate their levels. The aim of this study was to localize the antioxidant enzyme glutathione peroxidase 1 (Gpx1) at the spheno-occipital synchondrosis, as well as its effect on ROS challenge and its expression pattern in the course of differentiation. PMID:25312980

Koretsi, Vasiliki; Kirschneck, Christian; Proff, Peter; Römer, Piero

2014-10-13

360

The Relationship of Thioredoxin-1 and Cisplatin Resistance: Its Impact on ROS and Oxidative Metabolism in Lung Cancer Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Elimination of cisplatin resistant (CR) lung cancer cells remains a major obstacle. We have shown that CR tumors have higher reactive oxygen species (ROS) levels and can be exploited for targeted therapy. Here we show that increased secretion of the antioxidant thioredoxin-1 (TRX1) resulted in lowered intracellular TRX1, and contributed to higher ROS in CR tumors in vivo and in vitro. By reconstitutingTRX1 protein in CR cells, we increased sensitivity to cisplatin but decreased sensitivity to...

Wangpaichitr, Medhi; Theodoropoulos, George; Wu, Chunjing; You, Min; Feun, Lynn G.; Kuo, Macus T.; Savaraj, Niramol

2012-01-01

 
 
 
 
361

ROS1 Asp2213Asn polymorphism is not associated with coronary artery disease in a Greek case-control study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Rs619203 (Cys2229Ser) and rs529038 (Asp2213Asn) polymorphisms in the ROS1 gene have been studied in relation to myocardial infarction (MI) yielding inconsistent results. We investigated the role of ROS1 rs529038 polymorphism in coronary artery disease (CAD) in Greeks using a case-control study. Methods: Genotyping for rs529038 polymorphism was performed using a multiplex PCR technique in patients with CAD (n=294) and controls (n=311). Logistic regression analysis was used to calc...

Theodoraki, Eirini V.; Nikopensius, Tiit; Suhoruts?enko, Julia; Papamikos, Vassileios; Kolovou, Genovefa D.; Peppes, Vassileios; Panagiotakos, Demosthenes; Limberi, Sasa; Zakopoulos, Nikolaos; Metspalu, Andres; Dedoussis, George V.

2009-01-01

362

Membrane depolarization is the trigger for PI3K/Akt activation and leads to the generation of ROS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Loss of fluid shear stress (ischemia) to the lung endothelium causes endothelial plasma membrane depolarization via ATP-sensitive K+ (KATP) channel closure, initiating a signaling cascade that leads to NADPH oxidase (NOX2) activation and ROS production. Since wortmannin treatment significantly reduces ROS production with ischemia, we investigated the role of phosphoinositide 3-kinase (PI3K) in shear-associated signaling. Pulmonary microvascular endothelial cells in perfused lungs subjected to...

Chatterjee, Shampa; Browning, Elizabeth A.; Hong, Nankang; Debolt, Kris; Sorokina, Elena M.; Liu, Weidong; Birnbaum, Morris J.; Fisher, Aron B.

2012-01-01

363

Ca2+-modulated ROS-GC1 transduction system in testes and its presence in the spermatogenic cells  

Directory of Open Access Journals (Sweden)

Full Text Available ROS-GC1 belongs to the Ca2+-modulated sub-family of membrane guanylate cyclases. It primarily exists and is linked with signaling of the sensory neurons – sight, smell, taste and pinealocytes. Exceptionally, it is also present and is Ca2+-modulated in the non-neuronal cells, the sperm cells in the testes, where S100B protein serves its Ca2+ sensor. The present report demonstrates the identification of an additional Ca2+ sensor of ROS-GC1 in the testes, neurocalcin ?. Through mouse molecular genetic models, it compares and quantifies the relative input of the S100B and neurocalcin ? in regulating the Ca2+ signaling of ROS-GC1 transduction machinery, and via immunochemistry it demonstrates the co-presence of neurocalcin ? and ROS-GC1 in the spermatogenic cells of the testes. The suggestion is that in more ways than one the Ca2+-modulated ROS-GC1 transduction system is linked with the testicular function. This non-neuronal transduction system may represent an illustration of the ROS-GC1 expanding role in the trans-signaling of the neural and non-neural systems.

Anna Jankowska

2014-04-01