Science.gov

Sample records for mehg-induced ros production

  1. Optogenetic control of ROS production

    PubMed Central

    Wojtovich, Andrew P.; Foster, Thomas H.

    2014-01-01

    Reactive Oxygen Species (ROS) are known to cause oxidative damage to DNA, proteins and lipids. In addition, recent evidence suggests that ROS can also initiate signaling cascades that respond to stress and modify specific redox-sensitive moieties as a regulatory mechanism. This suggests that ROS are physiologically-relevant signaling molecules. However, these sensor/effector molecules are not uniformly distributed throughout the cell. Moreover, localized ROS damage may elicit site-specific compensatory measures. Thus, the impact of ROS can be likened to that of calcium, a ubiquitous second messenger, leading to the prediction that their effects are exquisitely dependent upon their location, quantity and even the timing of generation. Despite this prediction, ROS signaling is most commonly intuited through the global administration of chemicals that produce ROS or by ROS quenching through global application of antioxidants. Optogenetics, which uses light to control the activity of genetically-encoded effector proteins, provides a means of circumventing this limitation. Photo-inducible genetically-encoded ROS-generating proteins (RGPs) were originally employed for their phototoxic effects and cell ablation. However, reducing irradiance and/or fluence can achieve sub-lethal levels of ROS that may mediate subtle signaling effects. Hence, transgenic expression of RGPs as fusions to native proteins gives researchers a new tool to exert spatial and temporal control over ROS production. This review will focus on the new frontier defined by the experimental use of RGPs to study ROS signaling. PMID:24563855

  2. Oxidation of NADH and ROS production by respiratory complex I.

    PubMed

    Vinogradov, Andrei D; Grivennikova, Vera G

    2016-07-01

    Kinetic characteristics of the proton-pumping NADH:quinone reductases (respiratory complexes I) are reviewed. Unsolved problems of the redox-linked proton translocation activities are outlined. The parameters of complex I-mediated superoxide/hydrogen peroxide generation are summarized, and the physiological significance of mitochondrial ROS production is discussed. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt. PMID:26571336

  3. MK2 Regulates Ras Oncogenesis through Stimulating ROS Production

    PubMed Central

    Kobayashi, Yusuke; Qi, Xiaomei

    2012-01-01

    Ras signals through both mitogenic and stress pathways and studies of Ras regulatory effects of stress pathways hold great promise to control Ras-dependent malignancies. Our previous work showed Ras activation of a stress kinase (MAPK-activated protein kinase 2 [MK2]), and here, we examine regulatory effects of MK2 on Ras oncogenesis. MK2 knockout was shown to increase Ras transformation in mouse embryonic fibroblasts (MEFs) in vitro and to enhance the resultant tumor growth in mice, indicating a tumor suppressor activity. In Ras-dependent and -independent human colon cancer, however, MK2-forced expression increases and MK2 depletion decreases the malignant growth, suggesting its oncogenic activity. The oncogenic activity of MK2 couples with its activation by both stress and mitogenic signals through extracellular signal–regulated kinase and p38α pathways, whereas its tumor-suppressing effect links to its stimulation only by stress downstream of p38α. Of interest, MK2 was shown to decrease intracellular levels of reactive oxygen species (ROS) in MEFs but increase its production in human colon cancer cells, and experiments with antioxidants revealed that ROS is required for Ras oncogenesis in both systems. These results indicate that MK2 can increase or decrease Ras oncogenesis dependent of its ROS regulatory activities. PMID:23264852

  4. Antioxidants successfully reduce ROS production in propionic acidemia fibroblasts.

    PubMed

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

    2014-09-26

    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

  5. Crosstalk between ROS Homeostasis and Secondary Metabolism in S. natalensis ATCC 27448: Modulation of Pimaricin Production by Intracellular ROS

    PubMed Central

    Santos, Catarina L.; Osório, Hugo; Moradas-Ferreira, Pedro; Mendes, Marta V.

    2011-01-01

    Streptomyces secondary metabolism is strongly affected by oxygen availability. The increased culture aeration enhances pimaricin production in S. natalensis, however the excess of O2 consumption can lead to an intracellular ROS imbalance that is harmful to the cell. The adaptive physiological response of S. natalensis upon the addition of exogenous H2O2 suggested that the modulation of the intracellular ROS levels, through the activation of the H2O2 inducible catalase during the late exponential growth phase, can alter the production of pimaricin. With the construction of defective mutants on the H2O2 related enzymes SodF, AhpCD and KatA1, an effective and enduring modulation of intracellular ROS was achieved. Characterization of the knock-out strains revealed different behaviours regarding pimaricin production: whilst the superoxide dismutase defective mutant presented low levels of pimaricin production compared to the wild-type, the mutants defective on the H2O2-detoxifying enzymes displayed a pimaricin overproducer phenotype. Using physiological and molecular approaches we report a crosstalk between oxidative stress and secondary metabolism regulatory networks. Our results reveal that the redox-based regulation network triggered by an imbalance of the intracellular ROS homeostasis is also able to modulate the biosynthesis of pimaricin in S. natalensis. PMID:22114674

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

    PubMed

    Shabalina, Irina G; Vrbacký, Marek; Pecinová, Alena; Kalinovich, Anastasia V; Drahota, Zdeněk; Houštěk, Josef; Mráček, Tomáš; Cannon, Barbara; Nedergaard, Jan

    2014-12-01

    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

  7. Training Effects on ROS Production Determined by Electron Paramagnetic Resonance in Master Swimmers

    PubMed Central

    Mrakic-Sposta, Simona; Gussoni, Maristella; Porcelli, Simone; Pugliese, Lorenzo; Pavei, Gaspare; Bellistri, Giuseppe; Montorsi, Michela; Tacchini, Philippe; Vezzoli, Alessandra

    2015-01-01

    Acute exercise induces an increase in Reactive Oxygen Species (ROS) production dependent on exercise intensity with highest ROS amount generated by strenuous exercise. However, chronic repetition of exercise, that is, exercise training, may reduce exercise-induced oxidative stress. Aim of this study was to evaluate the effects of 6-weeks high-intensity discontinuous training (HIDT), characterized by repeated variations of intensity and changes of redox potential, on ROS production and antioxidant capacity in sixteen master swimmers. Time course changes of ROS generation were assessed by Electron Paramagnetic Resonance in capillary blood by a microinvasive approach. An incremental arm-ergometer exercise (IE) until exhaustion was carried out at both before (PRE) and after (POST) training (Trg) period. A significant (P < 0.01) increase of ROS production from REST to the END of IE in PRE Trg (2.82 ± 0.66 versus 3.28 ± 0.66 µmol·min−1) was observed. HIDT increased peak oxygen consumption (36.1 ± 4.3 versus 40.6 ± 5.7 mL·kg−1·min−1 PRE and POST Trg, resp.) and the antioxidant capacity (+13%) while it significantly decreased the ROS production both at REST (−20%) and after IE (−25%). The observed link between ROS production, adaptive antioxidant defense mechanisms, and peak oxygen consumption provides new insight into the correlation between ROS response pathways and muscle metabolic function. PMID:25874024

  8. Training effects on ROS production determined by electron paramagnetic resonance in master swimmers.

    PubMed

    Mrakic-Sposta, Simona; Gussoni, Maristella; Porcelli, Simone; Pugliese, Lorenzo; Pavei, Gaspare; Bellistri, Giuseppe; Montorsi, Michela; Tacchini, Philippe; Vezzoli, Alessandra

    2015-01-01

    Acute exercise induces an increase in Reactive Oxygen Species (ROS) production dependent on exercise intensity with highest ROS amount generated by strenuous exercise. However, chronic repetition of exercise, that is, exercise training, may reduce exercise-induced oxidative stress. Aim of this study was to evaluate the effects of 6-weeks high-intensity discontinuous training (HIDT), characterized by repeated variations of intensity and changes of redox potential, on ROS production and antioxidant capacity in sixteen master swimmers. Time course changes of ROS generation were assessed by Electron Paramagnetic Resonance in capillary blood by a microinvasive approach. An incremental arm-ergometer exercise (IE) until exhaustion was carried out at both before (PRE) and after (POST) training (Trg) period. A significant (P < 0.01) increase of ROS production from REST to the END of IE in PRE Trg (2.82 ± 0.66 versus 3.28 ± 0.66 µmol·min(-1)) was observed. HIDT increased peak oxygen consumption (36.1 ± 4.3 versus 40.6 ± 5.7 mL·kg(-1)·min(-1) PRE and POST Trg, resp.) and the antioxidant capacity (+13%) while it significantly decreased the ROS production both at REST (-20%) and after IE (-25%). The observed link between ROS production, adaptive antioxidant defense mechanisms, and peak oxygen consumption provides new insight into the correlation between ROS response pathways and muscle metabolic function. PMID:25874024

  9. Life-history Constraints on the Mechanisms that Control the Rate of ROS Production

    PubMed Central

    Aledo, Juan Carlos

    2014-01-01

    The quest to understand why and how we age has led to numerous lines of investigation that have gradually converged to consider mitochondrial metabolism as a major player. During mitochondrial respiration a small and variable amount of the consumed oxygen is converted to reactive species of oxygen (ROS). For many years, these ROS have been perceived as harmful by-products of respiration. However, evidence from recent years indicates that ROS fulfill important roles as cellular messengers. Results obtained using model organisms suggest that ROS-dependent signalling may even activate beneficial cellular stress responses, which eventually may lead to increased lifespan. Nevertheless, when an overload of ROS cannot be properly disposed of, its accumulation generates oxidative stress, which plays a major part in the ageing process. Comparative studies about the rates of ROS production and oxidative damage accumulation, have led to the idea that the lower rate of mitochondrial oxygen radical generation of long-lived animals with respect to that of their short-lived counterpart, could be a primary cause of their slow ageing rate. A hitherto largely under-appreciated alternative view is that such lower rate of ROS production, rather than a cause may be a consequence of the metabolic constraints imposed for the large body sizes that accompany high lifespans. To help understanding the logical underpinning of this rather heterodox view, herein I review the current literature regarding the mechanisms of ROS formation, with particular emphasis on evolutionary aspects. PMID:24955029

  10. Enhanced aphid detoxification when confronted by a host with elevated ROS production

    PubMed Central

    Lei, Jiaxin; Zhu-Salzman, Keyan

    2015-01-01

    Reactive oxygen species (ROS) plays an important role in plant defense responses against bacteria, fungi and insect pests. Most recently, we have demonstrated that loss of Arabidopsis thaliana BOTRYTIS-INDUCED KINASE1 (BIK1) function releases its suppression of aphid-induced H2O2 production and cell death, rendering the bik1 mutant more resistant to green peach aphid (Myzus persicae) than wild-type plants. However, little is known regarding how ROS-related gene expression is correlated with bik1-mediated resistance to aphids, or whether these aphids biochemically respond to the oxidative stress. Here, we show that the bik1 mutant exhibited elevated basal expression of ROS-generating and -responsive genes, but not ROS-metabolizing genes. Conversely, we detected enhanced detoxification enzymatic activities in aphids reared on bik1 plants compared to those on wild-type plants, suggesting that aphids counter the oxidative stress associated with bik1 through elevated metabolic resistance. PMID:25932782

  11. Assessment of a Standardized ROS Production Profile in Humans by Electron Paramagnetic Resonance

    PubMed Central

    Mrakic-Sposta, Simona; Gussoni, Maristella; Montorsi, Michela; Porcelli, Simone; Vezzoli, Alessandra

    2012-01-01

    Despite the growing interest in the role of reactive oxygen species (ROS) in health and disease, reliable quantitative noninvasive methods for the assessment of oxidative stress in humans are still lacking. EPR technique, coupled to a specific spin probe (CMH: 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) is here presented as the method of choice to gain a direct measurement of ROS in biological fluids and tissues. The study aimed at demonstrating that, differently from currently available “a posteriori” assays of ROS-induced damage by means of biomolecules (e.g., proteins and lipids) spin-trapping EPR provides direct evidence of the “instantaneous” presence of radical species in the sample and, as signal areas are proportional to the number of excited electron spins, lead to absolute concentration levels. Using a recently developed bench top continuous wave system (e-scan EPR scanner, Bruker) dealing with very low ROS concentration levels in small (50 μL) samples, we successfully monitored rapid ROS production changes in peripheral blood of athletes after controlled exercise and sedentary subjects after antioxidant supplementation. The correlation between EPR results and data obtained by various enzymatic assays (e.g., protein carbonyls and thiobarbituric acid reactive substances) was determined too. Synthetically, our method allows reliable, quick, noninvasive quantitative determination of ROS in human peripheral blood. PMID:22900129

  12. Methylglyoxal induces cell death through endoplasmic reticulum stress-associated ROS production and mitochondrial dysfunction.

    PubMed

    Chan, Chi-Ming; Huang, Duen-Yi; Huang, Yi-Pin; Hsu, Shu-Hao; Kang, Lan-Ya; Shen, Chung-Min; Lin, Wan-Wan

    2016-09-01

    Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are two important leading causes of acquired blindness in developed countries. As accumulation of advanced glycation end products (AGEs) in retinal pigment epithelial (RPE) cells plays an important role in both DR and AMD, and the methylglyoxal (MGO) within the AGEs exerts irreversible effects on protein structure and function, it is crucial to understand the underlying mechanism of MGO-induced RPE cell death. Using ARPE-19 as the cell model, this study revealed that MGO induces RPE cell death through a caspase-independent manner, which relying on reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP) loss, intracellular calcium elevation and endoplasmic reticulum (ER) stress response. Suppression of ROS generation can reverse the MGO-induced ROS production, MMP loss, intracellular calcium increase and cell death. Moreover, store-operated calcium channel inhibitors MRS1845 and YM-58483, but not the inositol 1,4,5-trisphosphate (IP3) receptor inhibitor xestospongin C, can block MGO-induced ROS production, MMP loss and sustained intracellular calcium increase in ARPE-19 cells. Lastly, inhibition of ER stress by salubrinal and 4-PBA can reduce the MGO-induced intracellular events and cell death. Therefore, our data indicate that MGO can decrease RPE cell viability, resulting from the ER stress-dependent intracellular ROS production, MMP loss and increased intracellular calcium increase. As MGO is one of the components of drusen in AMD and is the AGEs adduct in DR, this study could provide a valuable insight into the molecular pathogenesis and therapeutic intervention of AMD and DR. PMID:27307396

  13. ROS/RNS Production in Water Using Various Discharge Plasma

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazuhiro; Satoh, Kohki; Itoh, Hidenori; Kawaguchi, Hideki; Timoshkin, Igor; Given, Martin; MacGregor, Scott

    2015-09-01

    A pulsed discharge, a DC corona discharge and an atmospheric pressure plasma jet are generated above water, the off-gas of a packed-bed dielectric barrier discharge (PB-DBD) is sparged into water, and then reactive oxygen species and reactive nitrogen species in the water are investigated. H2O2, NO3- and a trace of NO2- are produced in the water after the plasma exposure. H2O2 concentration decreases when NO3- concentration increases, so that this is likely that OH radical to produce H2O2 by OH + OH -->H2O2 is consumed in the NO3- production by NO2 + OH --> HNO3 --> NO3-+ H+ (in water). Since no species is detected in water by the sparging of the PB-DBD off-gas containing more than 1000 ppm of O3, O3 does not contribute to produce H2O2 in water. Further, only NO3- is produced by the sparging of the off-gas containing N2O5 and HNO3. This leads that H2O2 and NO2- can be produced by short-lifetime species in plasma. In this work, the highest generation efficiency of H2O2 and NO2- are respectively 3,820 μg/Wh and 830 μg/Wh by the pulsed-plasma exposure, and that of NO3- is 2,530 μg/Wh by the off-gas sparging of the PB-DBD.

  14. Prostaglandin E₂ is critical for the development of niacin-deficiency-induced photosensitivity via ROS production.

    PubMed

    Sugita, Kazunari; Ikenouchi-Sugita, Atsuko; Nakayama, Yasuko; Yoshioka, Haruna; Nomura, Takashi; Sakabe, Jun-Ichi; Nakahigashi, Kyoko; Kuroda, Etsushi; Uematsu, Satoshi; Nakamura, Jun; Akira, Shizuo; Nakamura, Motonobu; Narumiya, Shuh; Miyachi, Yoshiki; Tokura, Yoshiki; Kabashima, Kenji

    2013-01-01

    Pellagra is a photosensitivity syndrome characterized by three "D's": diarrhea, dermatitis, and dementia as a result of niacin deficiency. However, the molecular mechanisms of photosensitivity dermatitis, the hallmark abnormality of this syndrome, remain unclear. We prepared niacin deficient mice in order to develop a murine model of pellagra. Niacin deficiency induced photosensitivity and severe diarrhea with weight loss. In addition, niacin deficient mice exhibited elevated expressions of COX-2 and PGE syntheses (Ptges) mRNA. Consistently, photosensitivity was alleviated by a COX inhibitor, deficiency of Ptges, or blockade of EP4 receptor signaling. Moreover, enhanced PGE2 production in niacin deficiency was mediated via ROS production in keratinocytes. In line with the above murine findings, human skin lesions of pellagra patients confirmed the enhanced expression of Ptges. Niacin deficiency-induced photosensitivity was mediated through EP4 signaling in response to increased PGE2 production via induction of ROS formation. PMID:24131900

  15. Neuronal NAD(P)H Oxidases Contribute to ROS Production and Mediate RGC Death after Ischemia

    PubMed Central

    Dvoriantchikova, Galina; Grant, Jeff; Santos, Andrea Rachelle C.; Hernandez, Eleut; Ivanov, Dmitry

    2012-01-01

    Purpose. To study the role of neuronal nicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidase–dependent reactive oxygen species (ROS) production in retinal ganglion cell (RGC) death after ischemia. Methods. Ischemic injury was induced by unilateral elevation of intraocular pressure via direct corneal cannulation. For in vitro experiments, RGCs isolated by immunopanning from retinas were exposed to oxygen and glucose deprivation (OGD). The expression levels of NAD(P)H oxidase subunits were evaluated by quantitative PCR, immunocytochemistry, and immunohistochemistry. The level of ROS generated was assayed by dihydroethidium. The NAD(P)H oxidase inhibitors were then tested to determine if inhibition of NAD(P)H oxidase altered the production of ROS within the RGCs and promoted cell survival. Results. It was reported that RGCs express catalytic Nox1, Nox2, Nox4, Duox1, as well as regulatory Ncf1/p47phox, Ncf2/p67phox, Cyba/p22phox, Noxo1, and Noxa1 subunits of NAD(P)H oxidases under normal conditions and after ischemia. However, whereas RGCs express only low levels of catalytic Nox2, Nox4, and Duox1, and regulatory Ncf1/p47, Ncf2/p67 subunits, they exhibit significantly higher levels of catalytic subunit Nox1 and the subunits required for optimal activity of Nox1. It was observed that the nonselective NAD(P)H oxidase inhibitors VAS-2870, AEBSF, and the Nox1 NAD(P)H oxidase–specific inhibitor ML-090 decreased the ROS burst stimulated by OGD, which was associated with a decreased level of RGC death. Conclusions. The findings suggest that NAD(P)H oxidase activity in RGCs renders them vulnerable to ischemic death. Importantly, high levels of Nox1 NAD(P)H oxidase subunits in RGCs suggest that this enzyme could be a major source of ROS in RGCs produced by NAD(P)H oxidases. PMID:22467573

  16. Oleic, Linoleic and Linolenic Acids Increase ROS Production by Fibroblasts via NADPH Oxidase Activation

    PubMed Central

    Hatanaka, Elaine; Dermargos, Alexandre; Hirata, Aparecida Emiko; Vinolo, Marco Aurélio Ramirez; Carpinelli, Angelo Rafael; Newsholme, Philip; Armelin, Hugo Aguirre; Curi, Rui

    2013-01-01

    The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47phox phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47phox mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts. PMID:23579616

  17. Oleic, linoleic and linolenic acids increase ros production by fibroblasts via NADPH oxidase activation.

    PubMed

    Hatanaka, Elaine; Dermargos, Alexandre; Hirata, Aparecida Emiko; Vinolo, Marco Aurélio Ramirez; Carpinelli, Angelo Rafael; Newsholme, Philip; Armelin, Hugo Aguirre; Curi, Rui

    2013-01-01

    The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47 (phox) phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47 (phox) mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts. PMID:23579616

  18. The Role of Mitochondrial Functional Proteins in ROS Production in Ischemic Heart Diseases

    PubMed Central

    Pei, Haifeng; Yang, Yi; Zhao, Heng; Li, Xiuchuan; Yang, Dachun; Li, De; Yang, Yongjian

    2016-01-01

    Ischemic heart diseases (IHD) have become the leading cause of death around the world, killing more than 7 million people annually. In IHD, the blockage of coronary vessels will cause irreversible cell injury and even death. As the “powerhouse” and “apoptosis center” in cardiomyocytes, mitochondria play critical roles in IHD. Ischemia insult can reduce myocardial ATP content, resulting in energy stress and overproduction of reactive oxygen species (ROS). Thus, mitochondrial abnormality has been identified as a hallmark of multiple cardiovascular disorders. To date, many studies have suggested that these mitochondrial proteins, such as electron transport chain (ETC) complexes, uncoupling proteins (UCPs), mitochondrial dynamic proteins, translocases of outer membrane (Tom) complex, and mitochondrial permeability transition pore (MPTP), can directly or indirectly influence mitochondria-originated ROS production, consequently determining the degree of mitochondrial dysfunction and myocardial impairment. Here, the focus of this review is to summarize the present understanding of the relationship between some mitochondrial functional proteins and ROS production in IHD. PMID:27119006

  19. Tanshinone IIA blocks dexamethasone-induced apoptosis in osteoblasts through inhibiting Nox4-derived ROS production

    PubMed Central

    Li, Jia; He, Chongru; Tong, Wenwen; Zou, Yuming; Li, Dahe; Zhang, Chen; Xu, Weidong

    2015-01-01

    Apoptosis of osteoblasts caused by glucocorticoids has been identified as an important contributor to the development of osteoporosis. Tanshinone IIA (Tan), an active ingredient extracted from the rhizome of the Salvia miltiorrhiza Bunge (Danshen), has been reported to cast positive effects on osteoporosis. However, the precise mechanisms accounting this action remain elusive. In this study, by using osteoblastic MC3T3-E1 cells as a model, we confirmed the protective effects of Tan against dexamethasone (Dex)-induced cell apoptosis and further clarified its molecular mechanism of action. Our results showed that treatment with Dex caused cell injury, increased cytosol cytochrome c level and Nox expression, induced apoptosis in caspase-9-dependent manner, and enhanced reactive oxygen species (ROS) production. Tan attenuated these deleterious consequence triggered by Dex. Moreover, Dex-induced ROS production and cell injury were inhibited by antioxidant, NADPH oxidases inhibitors, Nox4 inhibitor, and Nox4 small interfering RNA (siRNA). Overexpression of Nox4 almost abolished the inhibitory effect of Tan on Dex-induced cell injury and apoptosis. The results also demonstrated significant involvement of Nox4 in the Dex-induced apoptosis. Nox4-derived ROS led to apoptosis through activation of intrinsic mitochondrial pathway. Additionally, we evidenced that Tan reversed Dex-induced apoptosis via inactivation of Nox4. The present findings suggest that inhibition of Nox4 may be a novel therapeutic approach of Tan to prevent against glucocorticoids-induced osteoblasts apoptosis and osteoporosis. PMID:26722597

  20. Loss of UCP2 attenuates mitochondrial dysfunction without altering ROS production and uncoupling activity.

    PubMed

    Kukat, Alexandra; Dogan, Sukru Anil; Edgar, Daniel; Mourier, Arnaud; Jacoby, Christoph; Maiti, Priyanka; Mauer, Jan; Becker, Christina; Senft, Katharina; Wibom, Rolf; Kudin, Alexei P; Hultenby, Kjell; Flögel, Ulrich; Rosenkranz, Stephan; Ricquier, Daniel; Kunz, Wolfram S; Trifunovic, Aleksandra

    2014-06-01

    Although mitochondrial dysfunction is often accompanied by excessive reactive oxygen species (ROS) production, we previously showed that an increase in random somatic mtDNA mutations does not result in increased oxidative stress. Normal levels of ROS and oxidative stress could also be a result of an active compensatory mechanism such as a mild increase in proton leak. Uncoupling protein 2 (UCP2) was proposed to play such a role in many physiological situations. However, we show that upregulation of UCP2 in mtDNA mutator mice is not associated with altered proton leak kinetics or ROS production, challenging the current view on the role of UCP2 in energy metabolism. Instead, our results argue that high UCP2 levels allow better utilization of fatty acid oxidation resulting in a beneficial effect on mitochondrial function in heart, postponing systemic lactic acidosis and resulting in longer lifespan in these mice. This study proposes a novel mechanism for an adaptive response to mitochondrial cardiomyopathy that links changes in metabolism to amelioration of respiratory chain deficiency and longer lifespan. PMID:24945157

  1. Loss of UCP2 Attenuates Mitochondrial Dysfunction without Altering ROS Production and Uncoupling Activity

    PubMed Central

    Kukat, Alexandra; Dogan, Sukru Anil; Edgar, Daniel; Mourier, Arnaud; Jacoby, Christoph; Maiti, Priyanka; Mauer, Jan; Becker, Christina; Senft, Katharina; Wibom, Rolf; Kudin, Alexei P.; Hultenby, Kjell; Flögel, Ulrich; Rosenkranz, Stephan; Ricquier, Daniel; Kunz, Wolfram S.; Trifunovic, Aleksandra

    2014-01-01

    Although mitochondrial dysfunction is often accompanied by excessive reactive oxygen species (ROS) production, we previously showed that an increase in random somatic mtDNA mutations does not result in increased oxidative stress. Normal levels of ROS and oxidative stress could also be a result of an active compensatory mechanism such as a mild increase in proton leak. Uncoupling protein 2 (UCP2) was proposed to play such a role in many physiological situations. However, we show that upregulation of UCP2 in mtDNA mutator mice is not associated with altered proton leak kinetics or ROS production, challenging the current view on the role of UCP2 in energy metabolism. Instead, our results argue that high UCP2 levels allow better utilization of fatty acid oxidation resulting in a beneficial effect on mitochondrial function in heart, postponing systemic lactic acidosis and resulting in longer lifespan in these mice. This study proposes a novel mechanism for an adaptive response to mitochondrial cardiomyopathy that links changes in metabolism to amelioration of respiratory chain deficiency and longer lifespan. PMID:24945157

  2. Plant signaling networks involving Ca2+ and Rboh/Nox-mediated ROS production under salinity stress

    PubMed Central

    Kurusu, Takamitsu; Kuchitsu, Kazuyuki; Tada, Yuichi

    2015-01-01

    Salinity stress, which induces both ionic and osmotic damage, impairs plant growth and causes severe reductions in crop yield. Plants are equipped with defense responses against salinity stress such as regulation of ion transport including Na+ and K+, accumulation of compatible solutes and stress-related gene expression. The initial Ca2+ influx mediated by plasma membrane ion channels has been suggested to be crucial for the adaptive signaling. NADPH oxidase (Nox)-mediated production of reactive oxygen species (ROS) has also been suggested to play crucial roles in regulating adaptation to salinity stress in several plant species including halophytes. Respiratory burst oxidase homolog (Rboh) proteins show the ROS-producing Nox activity, which are synergistically activated by the binding of Ca2+ to EF-hand motifs as well as Ca2+-dependent phosphorylation. We herein review molecular identity, structural features and roles of the Ca2+-permeable channels involved in early salinity and osmotic signaling, and comparatively discuss the interrelationships among spatiotemporal dynamic changes in cytosolic concentrations of free Ca2+, Rboh-mediated ROS production, and downstream signaling events during salinity adaptation in planta. PMID:26113854

  3. Loss of SDHB Elevates Catecholamine Synthesis and Secretion Depending on ROS Production and HIF Stabilization.

    PubMed

    Saito, Yuria; Ishii, Kiyo-Aki; Aita, Yuichi; Ikeda, Tatsuhiko; Kawakami, Yasushi; Shimano, Hitoshi; Hara, Hisato; Takekoshi, Kazuhiro

    2016-04-01

    Germline mutations in genes encoding succinate dehydrogenase subunits are associated with the development of familial pheochromocytomas and paragangliomas [hereditary paraganglioma/pheochromocytoma syndrome (HPPS)]. In particular, a mutation in succinate dehydrogenase subunit B (SDHB) is highly associated with abdominal paraganglioma and subsequent distant metastasis (malignant paraganglioma), indicating the importance of SDHB genetic testing. The discovery of HPPS suggests an association among genetic mitochondrial defects, tumor development, and catecholamine oversecretion. To investigate this association, we transfected pheochromocytoma cells (PC12) with SDHB-specific siRNA. SDHB silencing virtually abolished complex II activity, demonstrating the utility of this in vitro model for investigating the pseudo-hypoxic drive hypothesis. Lack of complex II activity resulting from RNA interference of SDHB increased tyrosine hydroxylase (TH; the rate-limiting enzyme in catecholamine biosynthesis) activity and catecholamine secretion. Reduced apoptosis was observed accompanied by Bcl-2 accumulation in PC12 cells, consistent with the phenotypes of paragangliomas with SDHB mutations. In addition, SDHB silencing increased reactive oxygen species (ROS) production and nuclear HIF1α stabilization under normoxic conditions. Furthermore, phenotypes induced by complex II activity knockdown were abolished by pretreatment with N-acetyl cysteine (an ROS scavenger) and by prior HIF1α knockdown, indicating an ROS- and HIF1α-dependent mechanism. Our results indicate that increased ROS may act as signal transduction messengers that induce HIF1α stabilization and may be necessary for the pseudo-hypoxic states observed in our experimental model. To our knowledge, this is the first study demonstrating that pseudo-hypoxic states resulting from SDHB knockdown are associated with increased TH activity and catecholamine oversecretion. PMID:26620190

  4. Spin Biochemistry Modulates Reactive Oxygen Species (ROS) Production by Radio Frequency Magnetic Fields

    PubMed Central

    Usselman, Robert J.; Hill, Iain; Singel, David J.; Martino, Carlos F.

    2014-01-01

    The effects of weak magnetic fields on the biological production of reactive oxygen species (ROS) from intracellular superoxide (O2•−) and extracellular hydrogen peroxide (H2O2) were investigated in vitro with rat pulmonary arterial smooth muscle cells (rPASMC). A decrease in O2•− and an increase in H2O2 concentrations were observed in the presence of a 7 MHz radio frequency (RF) at 10 μTRMS and static 45 μT magnetic fields. We propose that O2•− and H2O2 production in some metabolic processes occur through singlet-triplet modulation of semiquinone flavin (FADH•) enzymes and O2•− spin-correlated radical pairs. Spin-radical pair products are modulated by the 7 MHz RF magnetic fields that presumably decouple flavin hyperfine interactions during spin coherence. RF flavin hyperfine decoupling results in an increase of H2O2 singlet state products, which creates cellular oxidative stress and acts as a secondary messenger that affects cellular proliferation. This study demonstrates the interplay between O2•− and H2O2 production when influenced by RF magnetic fields and underscores the subtle effects of low-frequency magnetic fields on oxidative metabolism, ROS signaling, and cellular growth. PMID:24681944

  5. Ethanol increases matrix metalloproteinase-12 expression via NADPH oxidase-dependent ROS production in macrophages.

    PubMed

    Kim, Mi Jin; Nepal, Saroj; Lee, Eung-Seok; Jeong, Tae Cheon; Kim, Sang-Hyun; Park, Pil-Hoon

    2013-11-15

    Matrix metalloproteinase-12 (MMP-12), an enzyme responsible for degradation of extracellular matrix, plays an important role in the progression of various diseases, including inflammation and fibrosis. Although most of those are pathogenic conditions induced by ethanol ingestion, the effect of ethanol on MMP-12 has not been explored. In the present study, we investigated the effect of ethanol on MMP-12 expression and its potential mechanisms in macrophages. Here, we demonstrated that ethanol treatment increased MMP-12 expression in primary murine peritoneal macrophages and RAW 264.7 macrophages at both mRNA and protein levels. Ethanol treatment also significantly increased the activity of nicotinamide adenine dinucleotide (NADPH) oxidase and the expression of NADPH oxidase-2 (Nox2). Pretreatment with an anti-oxidant (N-acetyl cysteine) or a selective inhibitor of NADPH oxidase (diphenyleneiodonium chloride (DPI)) prevented ethanol-induced MMP-12 expression. Furthermore, knockdown of Nox2 by small interfering RNA (siRNA) prevented ethanol-induced ROS production and MMP-12 expression in RAW 264.7 macrophages, indicating a critical role for Nox2 in ethanol-induced intracellular ROS production and MMP-12 expression in macrophages. We also showed that ethanol-induced Nox2 expression was suppressed by transient transfection with dominant negative IκB-α plasmid or pretreatment with Bay 11-7082, a selective inhibitor of NF-κB, in RAW 264.7 macrophages. In addition, ethanol-induced Nox2 expression was also attenuated by treatment with a selective inhibitor of p38 MAPK, suggesting involvement of p38 MAPK/NF-κB pathway in ethanol-induced Nox2 expression. Taken together, these results demonstrate that ethanol treatment elicited increase in MMP-12 expression via increase in ROS production derived from Nox2 in macrophages. PMID:23978445

  6. Ethanol increases matrix metalloproteinase-12 expression via NADPH oxidase-dependent ROS production in macrophages

    SciTech Connect

    Kim, Mi Jin; Nepal, Saroj; Lee, Eung-Seok; Jeong, Tae Cheon; Kim, Sang-Hyun; Park, Pil-Hoon

    2013-11-15

    Matrix metalloproteinase-12 (MMP-12), an enzyme responsible for degradation of extracellular matrix, plays an important role in the progression of various diseases, including inflammation and fibrosis. Although most of those are pathogenic conditions induced by ethanol ingestion, the effect of ethanol on MMP-12 has not been explored. In the present study, we investigated the effect of ethanol on MMP-12 expression and its potential mechanisms in macrophages. Here, we demonstrated that ethanol treatment increased MMP-12 expression in primary murine peritoneal macrophages and RAW 264.7 macrophages at both mRNA and protein levels. Ethanol treatment also significantly increased the activity of nicotinamide adenine dinucleotide (NADPH) oxidase and the expression of NADPH oxidase-2 (Nox2). Pretreatment with an anti-oxidant (N-acetyl cysteine) or a selective inhibitor of NADPH oxidase (diphenyleneiodonium chloride (DPI)) prevented ethanol-induced MMP-12 expression. Furthermore, knockdown of Nox2 by small interfering RNA (siRNA) prevented ethanol-induced ROS production and MMP-12 expression in RAW 264.7 macrophages, indicating a critical role for Nox2 in ethanol-induced intracellular ROS production and MMP-12 expression in macrophages. We also showed that ethanol-induced Nox2 expression was suppressed by transient transfection with dominant negative IκB-α plasmid or pretreatment with Bay 11-7082, a selective inhibitor of NF-κB, in RAW 264.7 macrophages. In addition, ethanol-induced Nox2 expression was also attenuated by treatment with a selective inhibitor of p38 MAPK, suggesting involvement of p38 MAPK/NF-κB pathway in ethanol-induced Nox2 expression. Taken together, these results demonstrate that ethanol treatment elicited increase in MMP-12 expression via increase in ROS production derived from Nox2 in macrophages. - Highlights: • Ethanol increases ROS production through up-regulation of Nox2 in macrophages. • Enhanced oxidative stress contributes to ethanol

  7. Liver Fibrosis Can Be Induced by High Salt Intake through Excess Reactive Oxygen Species (ROS) Production.

    PubMed

    Wang, Guang; Yeung, Cheung-kwan; Wong, Wing-Yan; Zhang, Nuan; Wei, Yi-fan; Zhang, Jing-li; Yan, Yu; Wong, Ching-yee; Tang, Jun-jie; Chuai, Manli; Lee, Kenneth Ka Ho; Wang, Li-jing; Yang, Xuesong

    2016-02-24

    High salt intake has been known to cause hypertension and other side effects. However, it is still unclear whether it also affects fibrosis in the mature or developing liver. This study demonstrates that high salt exposure in mice (4% NaCl in drinking water) and chick embryo (calculated final osmolality of the egg was 300 mosm/L) could lead to derangement of the hepatic cords and liver fibrosis using H&E, PAS, Masson, and Sirius red staining. Meanwhile, Desmin immunofluorescent staining of mouse and chick embryo livers indicated that hepatic stellate cells were activated after the high salt exposure. pHIS3 and BrdU immunohistological staining of mouse and chick embryo livers indicated that cell proliferation decreased; as well, TUNEL analyses indicated that cell apoptosis increased in the presence of high salt exposure. Next, dihydroethidium staining on the cultured chick hepatocytes indicated the excess ROS was generated following high salt exposure. Furthermore, AAPH (a known inducer of ROS production) treatment also induced the liver fibrosis in chick embryo. Positive Nrf2 and Keap1 immunohistological staining on mouse liver suggested that Nrf2/Keap1 signaling was involved in high salt induced ROS production. Finally, the CCK8 assay was used to determine whether or not the growth inhibitory effect induced by high salt exposure can be rescued by antioxidant vitamin C. Meanwhile, the RT-PCR result indicated that the Nrf2/Keap1 downsteam genes including HO-1, NQO-1, and SOD2 were involved in this process. In sum, these experiments suggest that high salt intake would lead to high risk of liver damage and fibrosis in both adults and developing embryos. The pathological mechanism may be the result from an imbalance between oxidative stress and the antioxidant system. PMID:26843032

  8. Autophagy induced by cathepsin S inhibition induces early ROS production, oxidative DNA damage, and cell death via xanthine oxidase.

    PubMed

    Huang, Chien-Chang; Chen, Kuo-Li; Cheung, Chun Hei Antonio; Chang, Jang-Yang

    2013-12-01

    Cathepsin S plays multiple roles in MHC class II antigen presentation, extracellular matrix degradation, angiogenesis, and tumorogenesis. Our previous study revealed that targeting cathepsin S could induce cellular cytotoxicity and reduce cell viability. For the current study, we further investigated the molecular mechanism responsible for targeting cathepsin S-induced cell death and its association with autophagy. Distinct from regulation of the classic autophagy pathway by reactive oxygen species (ROS), we demonstrated that autophagy is the genuine regulator of early ROS production. The molecular silencing of autophagy-dependent ATG genes (ATG5, ATG7, and LC3) and the pharmacologic inhibition of autophagy with 3-MA and wortmannin reduced ROS production significantly. In addition, xanthine oxidase (XO), which is upregulated by autophagy, is required for early ROS production, oxidative DNA damage, and consequent cell death. Autophagy inhibition suppresses the upregulation of XO, which is induced by cathepsin S inhibition, resulting in reduced ROS generation, DNA damage, and cell death. Collectively, our study reveals a noncanonical molecular pathway in which, after the inhibition of cathepsin S, autophagy induces early ROS production for oxidative DNA damage and cell death through XO. PMID:23892358

  9. A novel proteasome inhibitor acting in mitochondrial dysfunction, ER stress and ROS production.

    PubMed

    Maria, Durvanei Augusto; de Souza, Jean Gabriel; Morais, Katia L P; Berra, Carolina Maria; Zampolli, Hamilton de Campos; Demasi, Marilene; Simons, Simone Michaela; de Freitas Saito, Renata; Chammas, Roger; Chudzinski-Tavassi, Ana Marisa

    2013-06-01

    In cancer-treatment, potentially therapeutic drugs trigger their effects through apoptotic mechanisms. Generally, cell response is manifested by Bcl-2 family protein regulation, the impairment of mitochondrial functions, and ROS production. Notwithstanding, several drugs operate through proteasome inhibition, which, by inducing the accumulation and aggregation of misfolded or unfolded proteins, can lead to endoplasmic reticulum (ER) stress. Accordingly, it was shown that Amblyomin-X, a Kunitz-type inhibitor identified in the transcriptome of the Amblyomma cajennense tick by ESTs sequence analysis of a cDNA library, obtained in recombinant protein form, induces apoptosis in murine renal adenocarcinoma (RENCA) cells by: inducing imbalance between pro- and anti-apoptotic Bcl-2 family proteins, dysfunction/mitochondrial damage, production of reactive oxygen species (ROS), caspase cascade activation, and proteasome inhibition, all ER-stress inductive. Moreover, there was no manifest action on normal mouse-fibroblast cells (NHI3T3), suggesting an Amblyomin-X tumor-cell selectivity. Taken together, these evidences indicate that Amblyomin-X could be a promising candidate for cancer therapy. PMID:22975862

  10. Neoalbaconol induces cell death through necroptosis by regulating RIPK-dependent autocrine TNFα and ROS production

    PubMed Central

    Li, Wei; Xiao, Lanbo; Luo, Xiangjian; Liu, Xiaolan; Yang, Lifang; Peng, Songling; Ding, Zhihui; Feng, Tao; Zhou, Jian; Fan, Jia; Bode, Ann M.; Dong, Zigang; Liu, Jikai; Cao, Ya

    2015-01-01

    Necroptosis/regulated necrosis is a caspase-independent, but receptor interacting protein kinase (RIPK)-dependent form of cell death. In previous studies, neoalbaconol (NA), a constituent extracted from Albatrellus confluens, was demonstrated to induce necroptosis in some cancer cell lines. The molecular mechanism of NA-induced necroptosis is described in this research study. We determined that NA-induced cell death is partly dependent on tumor necrosis factor α (TNFα) feed-forward signaling. More importantly, NA abolished the ubiquitination of RIPK1 by down-regulating E3 ubiquitin ligases, cellular inhibitors of apoptosis protein 1/2 (cIAP1/2) and TNFα receptor-associated factors (TRAFs). The suppression of RIPK1 ubiquitination induced the activation of the non-canonical nuclear factor-κB (NF-κB) pathway and stimulated the transcription of TNFα. Moreover, we also found that NA caused RIPK3-mediated reactive oxygen species (ROS) production and contribution to cell death. Taken together, these results suggested that two distinct mechanisms are involved in NA-induced necroptosis and include RIPK1/NF-κB-dependent expression of TNFα and RIPK3-dependent generation of ROS. PMID:25575821

  11. Neoalbaconol induces cell death through necroptosis by regulating RIPK-dependent autocrine TNFα and ROS production.

    PubMed

    Yu, Xinfang; Deng, Qipan; Li, Wei; Xiao, Lanbo; Luo, Xiangjian; Liu, Xiaolan; Yang, Lifang; Peng, Songling; Ding, Zhihui; Feng, Tao; Zhou, Jian; Fan, Jia; Bode, Ann M; Dong, Zigang; Liu, Jikai; Cao, Ya

    2015-02-10

    Necroptosis/regulated necrosis is a caspase-independent, but receptor interacting protein kinase (RIPK)-dependent form of cell death. In previous studies, neoalbaconol (NA), a constituent extracted from Albatrellus confluens, was demonstrated to induce necroptosis in some cancer cell lines. The molecular mechanism of NA-induced necroptosis is described in this research study. We determined that NA-induced cell death is partly dependent on tumor necrosis factor α (TNFα) feed-forward signaling. More importantly, NA abolished the ubiquitination of RIPK1 by down-regulating E3 ubiquitin ligases, cellular inhibitors of apoptosis protein 1/2 (cIAP1/2) and TNFα receptor-associated factors (TRAFs). The suppression of RIPK1 ubiquitination induced the activation of the non-canonical nuclear factor-κB (NF-κB) pathway and stimulated the transcription of TNFα. Moreover, we also found that NA caused RIPK3-mediated reactive oxygen species (ROS) production and contribution to cell death. Taken together, these results suggested that two distinct mechanisms are involved in NA-induced necroptosis and include RIPK1/NF-κB-dependent expression of TNFα and RIPK3-dependent generation of ROS. PMID:25575821

  12. Increased ROS Production: A Component of the Longevity Equation in the Male Mygalomorph, Brachypelma albopilosa

    PubMed Central

    Criscuolo, Francois; Font-Sala, Candide; Bouillaud, Frederic; Poulin, Nicolas; Trabalon, Marie

    2010-01-01

    Background The diversity of longevities encountered in wildlife is one of the most intriguing problems in biology. Evolutionary biologists have proposed different theories to explain how longevity variability may be driven by bad genes expression in late life or by gene pleiotropic effects. This reflexion has stimulated, in the last ten years, an active research on the proximal mechanisms that can shape lifespan. Reactive oxygen species (ROS), i.e., the by-products of oxidative metabolism, have emerged as the main proximate cause of ageing. Because ROS are mainly produced by the mitochondria, their production is linked to metabolic rate, and this may explain the differences in longevity between large and small species. However, their implication in the sex difference in longevity within a species has never been tested, despite the fact that these differences are widespread in the animal kingdom. Methodology/Principal Findings Mitochondrial superoxide production of hemolymph immune cells and antioxidant and oxidative damages plasma levels were measured in adult male and female B. albopilosa at different ages. We found that female spiders are producing less mitochondrial superoxide, are better protected against oxidative attack and are then suffering less oxidative damages than males at adulthood. Conclusions/Significance In tarantulas, once reaching sexual maturity, males have a life expectancy reduced to 1 to 2 years, while females can still live for 20 years, in spite of the fact that females continue to grow and moult. This study evidences an increased exposure of males to oxidative stress due to an increase in mitochondrial superoxide production and a decrease in hemolymph antioxidant defences. Such a phenomenon is likely to be part of the explanation for the sharp reduction of longevity accompanying male tarantula maturity. This opens several fundamental research roads in the future to better understand how reproduction and longevity are linked in an original

  13. Antimicrobial peptide protonectin disturbs the membrane integrity and induces ROS production in yeast cells.

    PubMed

    Wang, Kairong; Dang, Wen; Xie, Junqiu; Zhu, Ranran; Sun, Mengyang; Jia, Fengjing; Zhao, Yanyan; An, Xiaoping; Qiu, Shuai; Li, Xiaoyuan; Ma, Zelin; Yan, Wenjin; Wang, Rui

    2015-10-01

    Candidiasis is often observed in immunocompromised patients and is the 4th most common cause of bloodstream infections. However, antifungals are limited, so novel antifungal agents are urgently needed. Antimicrobial peptides (AMPs) are considered as potential alternatives of conventional antibiotics. In the present study, antimicrobial peptide protonectin was chemically synthesized and its antifungal activity and mode of action were studied. Our results showed that protonectin has potent antifungal activity and fungicidal activity against the tested fungi cells. Its action mode involved the disruption of the membrane integrity and the inducing of the production of cellular ROS. Furthermore, protonectin could inhibit the formation of biofilm and kill the adherent fungi cells. In conclusion, with the increase of fungal infection, protonectin may offer a new strategy and be considered as a potential therapeutic agent against fungal disease. PMID:26209560

  14. Reactive oxygen species (ROS) production in human peripheral blood neutrophils exposed in vitro to static magnetic field.

    PubMed

    Poniedziałek, Barbara; Rzymski, Piotr; Karczewski, Jacek; Jaroszyk, Feliks; Wiktorowicz, Krzysztof

    2013-12-01

    The aim of this study was to determine the effect of gradient static magnetic field (SMF) on reactive oxygen species (ROS) production in human neutrophils in peripheral blood in vitro. Blood samples collected from healthy individuals were incubated in an inhomogeneous SMF (in a south or north pole of the field) for 15, 30 or 45 minutes. The maximum value of induction (B max) amounted to ≈ 60 mT. To determine the strength of the ROS production, dihydrorhodamine (123DHR) as fluorophore and phorbol 12-myristate 13-acetate (PMA) as respiratory burst stimulator were used. 123DHR oxidation by ROS was measured by flow cytometry. The exposure of blood samples to SMF induced statistically significant changes in ROS production in unstimulated and PMA-stimulated neutrophils. The observed effects were highly correlated with the exposure time and depended on the orientation of the field. Although intracellular mechanisms underlying such interactions are not thoroughly understood, it could be presumed that SMF affects ROS metabolic oscillations and their formation and inactivation. This study emphasizes the importance of proper adjustment of exposure time to SMF for any potential therapeutic applications. PMID:23631724

  15. ROS production as a common mechanism of ENaC regulation by EGF, insulin, and IGF-1

    PubMed Central

    Ilatovskaya, Daria V.; Pavlov, Tengis S.; Levchenko, Vladislav

    2013-01-01

    The epithelial Na+ channel (ENaC) is a key transporter participating in the fine tuning of Na+ reabsorption in the nephron. ENaC activity is acutely upregulated by epidermal growth factor (EGF), insulin, and insulin-like growth factor-1 (IGF-1). It was also proposed that reactive oxygen species (ROS) have a stimulatory effect on ENaC. Here we studied whether effects of EGF, insulin, and IGF-1 correlate with ROS production in the mouse cortical collecting duct (mpkCCDc14) cells. Western blotting confirmed the expression of the NADPH oxidase complex subunits in these cells. Treatment of mpkCCDc14 cells with EGF, insulin, or IGF-1 evoked an increase in ROS production as measured by CM-H2DCF-DA fluorescence. ROS production caused by a xanthine-xanthine oxidase reaction also resulted in a significant elevation in short-circuit current through the mpkCCDc14 monolayer. Transepithelial current measurements showed an acute increase of amiloride-sensitive current through the mpkCCDc14 monolayer in response to EGF, insulin, or IGF-1. Pretreatment with the nonselective NADPH oxidase activity inhibitor apocynin blunted both ROS production and increase in ENaC-mediated current in response to these drugs. To further test whether NADPH oxidase subunits are involved in the effect of EGF, we used a stable M-1 cell line with a knockdown of Rac1, which is one of the key subunits of the NADPH oxidase complex, and measured amiloride-sensitive currents in response to EGF. In contrast to control cells, EGF had no effect in Rac1 knockdown cells. We hypothesize that EGF, insulin, and IGF-1 have a common stimulatory effect on ENaC mediated by ROS production. PMID:23135700

  16. Apoplastic ROS production upon pollination by RbohH and RbohJ in Arabidopsis.

    PubMed

    Kaya, Hidetaka; Iwano, Megumi; Takeda, Seiji; Kanaoka, Masahiro M; Kimura, Sachie; Abe, Mitsutomo; Kuchitsu, Kazuyuki

    2015-01-01

    Reactive oxygen species (ROS) accumulate at the tip of growing pollen tubes. In Arabidopsis, NADPH oxidases RbohH and RbohJ are localized at the plasma membrane of pollen tube tip and produce ROS in a Ca(2+)-dependent manner. The ROS produced by Rbohs and Ca(2+) presumably play a critical role in the positive feedback regulation that maintains the tip growth. Ultrastructural cytochemical analysis revealed ROS accumulation in the apoplast/cell wall of the pollen grains on the stigmatic papillae in the wild type, but not in the rbohH rbohJ double mutant, suggesting that apoplastic ROS derived from RbohH and RbohJ are involved in pollen tube elongation into the stigmatic papillae by affecting the cell wall metabolism. PMID:25751652

  17. Ligustilide treatment promotes functional recovery in a rat model of spinal cord injury via preventing ROS production.

    PubMed

    Xiao, Weidong; Yu, Aixi; Liu, Danli; Shen, Jun; Xu, Zhigao

    2015-01-01

    Ligustilide from traditional Chinese medicine extract, angelica sinensis is one of the main active components, and has many pharmacological activities related to the effectiveness. This study sought to determine whether neuro-protection of ligustilide promotes functional recovery in a rat model of spinal cord injury (SCI) via preventing ROS production. Male Sprague-Dawley (SD) rats were induced using operation for model SCI. Furthermore, Basso, Beattie, Bresnahan (BBB) scale and footprint analysis of gait was used to assess the neuro-protection of ligustilide on SCI. The intracellular reactive oxygen species (iROS), prostaglandin E(2) (PGE(2)), interleukin-1β (IL-1β) and tumor necrosis factor (TNF)-α production levels were measured by monoclonal enzyme immunoassay kit. Inducible nitric oxide synthase (iNOS) gene expression, activator protein-1 (AP-1) and c-Jun N-terminal kinase (JNK) protein expressions were detected using Quantitative real-time reverse transcription polymerase chain reaction (Q-PCR) and western blot analyses, respectively. Interestingly, treatment with ligustilide significantly increased BBB scale and reduced recovery of coordination in SCI rats. After SCI, the iROS, PGE(2), IL-1β, TNF-α production levels and iNOS gene expression were significantly suppressed in SCI rats. These results suggest that the neuro-protection of ligustilide promotes functional recovery in a rat model of spinal cord injury via preventing ROS production. PMID:26722386

  18. Modulation of ROS production in photodynamic therapy using a pH controlled photoinduced electron transfer (PET) based sensitiser.

    PubMed

    Atchison, Jordan; Kamila, Sukanta; McEwan, Conor; Nesbitt, Heather; Davis, James; Fowley, Colin; Callan, Bridgeen; McHale, Anthony P; Callan, John F

    2015-12-01

    A new sensitiser (4) for use in photodynamic therapy (PDT) has been developed to enable control of ROS production as a function of pH. This pH dependent PDT behaviour was tested in HeLa cells and in SCID mice bearing human xenograft pancreatic cancer (BxPC-3) tumours. PMID:26435142

  19. Heme induces programmed necrosis on macrophages through autocrine TNF and ROS production.

    PubMed

    Fortes, Guilherme B; Alves, Leticia S; de Oliveira, Rosane; Dutra, Fabianno F; Rodrigues, Danielle; Fernandez, Patricia L; Souto-Padron, Thais; De Rosa, María José; Kelliher, Michelle; Golenbock, Douglas; Chan, Francis K M; Bozza, Marcelo T

    2012-03-01

    Diseases that cause hemolysis or myonecrosis lead to the leakage of large amounts of heme proteins. Free heme has proinflammatory and cytotoxic effects. Heme induces TLR4-dependent production of tumor necrosis factor (TNF), whereas heme cytotoxicity has been attributed to its ability to intercalate into cell membranes and cause oxidative stress. We show that heme caused early macrophage death characterized by the loss of plasma membrane integrity and morphologic features resembling necrosis. Heme-induced cell death required TNFR1 and TLR4/MyD88-dependent TNF production. Addition of TNF to Tlr4(-/-) or to Myd88(-/-) macrophages restored heme-induced cell death. The use of necrostatin-1, a selective inhibitor of receptor-interacting protein 1 (RIP1, also known as RIPK1), or cells deficient in Rip1 or Rip3 revealed a critical role for RIP proteins in heme-induced cell death. Serum, antioxidants, iron chelation, or inhibition of c-Jun N-terminal kinase (JNK) ameliorated heme-induced oxidative burst and blocked macrophage cell death. Macrophages from heme oxygenase-1 deficient mice (Hmox1(-/-)) had increased oxidative stress and were more sensitive to heme. Taken together, these results revealed that heme induces macrophage necrosis through 2 synergistic mechanisms: TLR4/Myd88-dependent expression of TNF and TLR4-independent generation of ROS. PMID:22262768

  20. Hirsutanol A, a novel sesquiterpene compound from fungus Chondrostereum sp., induces apoptosis and inhibits tumor growth through mitochondrial-independent ROS production: Hirsutanol A inhibits tumor growth through ROS production

    PubMed Central

    2013-01-01

    Background Hirsutanol A is a novel sesquiterpene compound purified from fungus Chondrostereum sp. in Sarcophyton tortuosum. Our previous studies had demonstrated that hirsutanol A exhibited potent cytotoxic effect on many kinds of cancer cell lines. In the current study, the antitumor activity of hirsutanol A and its molecular mechanisms were investigated. Methods Hirsutanol A induced growth inhibition and apoptotic cell death of human colon cancer SW620 cells and human breast cancer MDA-MB-231cells were determined using MTT assay and flow cytometry assay, respectively. The effect of hirsutanol A on intrinsic ROS level and change in mitochondrial membrane potential (△ψm) of different cell lines were also measured by flow cytometry assay. The function of JNK was compromised by JNK siRNA or JNK inhibitor SP600125. The expression of cytochrome c, p-JNK, p-c-Jun after treatment with hirsutanol A were detected by Western blot analysis. Finally, the in vivo anti-tumor effect of hirsutanol A was examined in human cancer cell SW620 xenograft model. Results The results showed that hirsutanol A significantly induced apoptosis, mitochondrial-independent increase of Reactive Oxygen Species (ROS) level, change of mitochondrial membrane potential, release of cytochrome c in human cancer cells. Preventing increase of ROS level using the potent antioxidant N-acetyl-L-cysteine (NAC) markedly decreased hirsutanol A-induced apoptosis. In addition, JNK signaling pathway was activated by hirsutanol A through elevating ROS level. Blockade of JNK signaling pathway by JNK specific inhibitor SP600125 enhanced apoptosis and hirsutanol A-induced ROS accumulation. Also, hirsutanol A exhibited antitumor activity in human cancer cell SW620 xenograft model. Conclusion These data suggested that hirsutanol A inhibited tumor growth through triggering ROS production and apoptosis. PMID:23394457

  1. DJ-1 links muscle ROS production with metabolic reprogramming and systemic energy homeostasis in mice.

    PubMed

    Shi, Sally Yu; Lu, Shun-Yan; Sivasubramaniyam, Tharini; Revelo, Xavier S; Cai, Erica P; Luk, Cynthia T; Schroer, Stephanie A; Patel, Prital; Kim, Raymond H; Bombardier, Eric; Quadrilatero, Joe; Tupling, A Russell; Mak, Tak W; Winer, Daniel A; Woo, Minna

    2015-01-01

    Reactive oxygen species (ROS) have been linked to a wide variety of pathologies, including obesity and diabetes, but ROS also act as endogenous signalling molecules, regulating numerous biological processes. DJ-1 is one of the most evolutionarily conserved proteins across species, and mutations in DJ-1 have been linked to some cases of Parkinson's disease. Here we show that DJ-1 maintains cellular metabolic homeostasis via modulating ROS levels in murine skeletal muscles, revealing a role of DJ-1 in maintaining efficient fuel utilization. We demonstrate that, in the absence of DJ-1, ROS uncouple mitochondrial respiration and activate AMP-activated protein kinase, which triggers Warburg-like metabolic reprogramming in muscle cells. Accordingly, DJ-1 knockout mice exhibit higher energy expenditure and are protected from obesity, insulin resistance and diabetes in the setting of fuel surplus. Our data suggest that promoting mitochondrial uncoupling may be a potential strategy for the treatment of obesity-associated metabolic disorders. PMID:26077864

  2. DJ-1 links muscle ROS production with metabolic reprogramming and systemic energy homeostasis in mice

    PubMed Central

    Shi, Sally Yu; Lu, Shun-Yan; Sivasubramaniyam, Tharini; Revelo, Xavier S.; Cai, Erica P.; Luk, Cynthia T.; Schroer, Stephanie A.; Patel, Prital; Kim, Raymond H.; Bombardier, Eric; Quadrilatero, Joe; Tupling, A. Russell; Mak, Tak W.; Winer, Daniel A.; Woo, Minna

    2015-01-01

    Reactive oxygen species (ROS) have been linked to a wide variety of pathologies, including obesity and diabetes, but ROS also act as endogenous signalling molecules, regulating numerous biological processes. DJ-1 is one of the most evolutionarily conserved proteins across species, and mutations in DJ-1 have been linked to some cases of Parkinson's disease. Here we show that DJ-1 maintains cellular metabolic homeostasis via modulating ROS levels in murine skeletal muscles, revealing a role of DJ-1 in maintaining efficient fuel utilization. We demonstrate that, in the absence of DJ-1, ROS uncouple mitochondrial respiration and activate AMP-activated protein kinase, which triggers Warburg-like metabolic reprogramming in muscle cells. Accordingly, DJ-1 knockout mice exhibit higher energy expenditure and are protected from obesity, insulin resistance and diabetes in the setting of fuel surplus. Our data suggest that promoting mitochondrial uncoupling may be a potential strategy for the treatment of obesity-associated metabolic disorders. PMID:26077864

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

    SciTech Connect

    Naha, Pratap C.; Davoren, Maria; Lyng, Fiona M.; Byrne, Hugh J.

    2010-07-15

    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 H{sub 2}DCFDA 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-{alpha} (TNF-{alpha}) 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 {approx} 4 h), TNF-{alpha} and IL-6 secretion (maximum at {approx} 24 h), MIP-2 levels and cell death ({approx} 72 h) was observed. The intracellular ROS generation and cytokine production induced cytotoxicity point towards the mechanistic pathway of cell death upon exposure to PAMAM dendrimers.

  4. The GTPase ARF6 Controls ROS Production to Mediate Angiotensin II-Induced Vascular Smooth Muscle Cell Proliferation

    PubMed Central

    Bourmoum, Mohamed; Charles, Ricardo; Claing, Audrey

    2016-01-01

    High reactive oxygen species (ROS) levels and enhanced vascular smooth muscle cells (VSMC) proliferation are observed in numerous cardiovascular diseases. The mechanisms by which hormones such as angiotensin II (Ang II) acts to promote these cellular responses remain poorly understood. We have previously shown that the ADP-ribosylation factor 6 (ARF6), a molecular switch that coordinates intracellular signaling events can be activated by the Ang II receptor (AT1R). Whether this small GTP-binding protein controls the signaling events leading to ROS production and therefore Ang II-dependent VSMC proliferation, remains however unknown. Here, we demonstrate that in rat aortic VSMC, Ang II stimulation led to the subsequent activation of ARF6 and Rac1, a key regulator of NADPH oxidase activity. Using RNA interference, we showed that ARF6 is essential for ROS generation since in conditions where this GTPase was knocked down, Ang II could no longer promote superoxide anion production. In addition to regulating Rac1 activity, ARF6 also controlled expression of the NADPH oxidase 1 (Nox 1) as well as the ability of the EGFR to become transactivated. Finally, ARF6 also controlled MAPK (Erk1/2, p38 and Jnk) activation, a key pathway of VSMC proliferation. Altogether, our findings demonstrate that Ang II promotes activation of ARF6 to controls ROS production by regulating Rac1 activation and Nox1 expression. In turn, increased ROS acts to activate the MAPK pathway. These signaling events represent a new molecular mechanism by which Ang II can promote proliferation of VSMC. PMID:26824355

  5. Modulation of mitochondrial respiratory function and ROS production by novel benzopyran analogues.

    PubMed

    Petruş, Alexandra; Duicu, Oana M; Sturza, Adrian; Noveanu, Lavinia; Kiss, Loránd; Dănilă, Maria; Baczkó, István; Muntean, Danina M; Jost, Norbert

    2015-09-01

    A substantial body of evidence indicates that pharmacological activation of mitochondrial ATP-sensitive potassium channels (mKATP) in the heart is protective in conditions associated with ischemia/reperfusion injury. Several mechanisms have been postulated to be responsible for cardioprotection, including the modulation of mitochondrial respiratory function. The aim of the present study was to characterize the dose-dependent effects of novel synthetic benzopyran analogues, derived from a BMS-191095, a selective mKATP opener, on mitochondrial respiration and reactive oxygen species (ROS) production in isolated rat heart mitochondria. Mitochondrial respiratory function was assessed by high-resolution respirometry, and H2O2 production was measured by the Amplex Red fluorescence assay. Four compounds, namely KL-1487, KL-1492, KL-1495, and KL-1507, applied in increasing concentrations (50, 75, 100, and 150 μmol/L, respectively) were investigated. When added in the last two concentrations, all compounds significantly increased State 2 and 4 respiratory rates, an effect that was not abolished by 5-hydroxydecanoate (5-HD, 100 μmol/L), the classic mKATP inhibitor. The highest concentration also elicited an important decrease of the oxidative phosphorylation in a K(+) independent manner. Both concentrations of 100 and 150 μmol/L for KL-1487, KL-1492, and KL-1495, and the concentration of 150 μmol/L for KL-1507, respectively, mitigated the mitochondrial H2O2 release. In isolated rat heart mitochondria, the novel benzopyran analogues act as protonophoric uncouplers of oxidative phosphorylation and decrease the generation of reactive oxygen species in a dose-dependent manner. PMID:26325241

  6. Prostaglandin E2 is critical for the development of niacin-deficiency-induced photosensitivity via ROS production

    NASA Astrophysics Data System (ADS)

    Sugita, Kazunari; Ikenouchi-Sugita, Atsuko; Nakayama, Yasuko; Yoshioka, Haruna; Nomura, Takashi; Sakabe, Jun-Ichi; Nakahigashi, Kyoko; Kuroda, Etsushi; Uematsu, Satoshi; Nakamura, Jun; Akira, Shizuo; Nakamura, Motonobu; Narumiya, Shuh; Miyachi, Yoshiki; Tokura, Yoshiki; Kabashima, Kenji

    2013-10-01

    Pellagra is a photosensitivity syndrome characterized by three ``D's'': diarrhea, dermatitis, and dementia as a result of niacin deficiency. However, the molecular mechanisms of photosensitivity dermatitis, the hallmark abnormality of this syndrome, remain unclear. We prepared niacin deficient mice in order to develop a murine model of pellagra. Niacin deficiency induced photosensitivity and severe diarrhea with weight loss. In addition, niacin deficient mice exhibited elevated expressions of COX-2 and PGE syntheses (Ptges) mRNA. Consistently, photosensitivity was alleviated by a COX inhibitor, deficiency of Ptges, or blockade of EP4 receptor signaling. Moreover, enhanced PGE2 production in niacin deficiency was mediated via ROS production in keratinocytes. In line with the above murine findings, human skin lesions of pellagra patients confirmed the enhanced expression of Ptges. Niacin deficiency-induced photosensitivity was mediated through EP4 signaling in response to increased PGE2 production via induction of ROS formation.

  7. The Xanthomonas campestris pv. vesicatoria Type-3 Effector XopB Inhibits Plant Defence Responses by Interfering with ROS Production.

    PubMed

    Priller, Johannes Peter Roman; Reid, Stephen; Konein, Patrick; Dietrich, Petra; Sonnewald, Sophia

    2016-01-01

    The bacterial pathogen Xanthomonas campestris pv. vesicatoria 85-10 (Xcv) translocates about 30 type-3 effector proteins (T3Es) into pepper plants (Capsicum annuum) to suppress plant immune responses. Among them is XopB which interferes with PTI, ETI and sugar-mediated defence responses, but the underlying molecular mechanisms and direct targets are unknown so far. Here, we examined the XopB-mediated suppression of plant defence responses in more detail. Infection of susceptible pepper plants with Xcv lacking xopB resulted in delayed symptom development compared to Xcv wild type infection concomitant with an increased formation of salicylic acid (SA) and expression of pathogenesis-related (PR) genes. Expression of xopB in Arabidopsis thaliana promoted the growth of the virulent Pseudomonas syringae pv. tomato (Pst) DC3000 strain. This was paralleled by a decreased SA-pool and a lower induction of SA-dependent PR gene expression. The expression pattern of early flg22-responsive marker genes indicated that MAPK signalling was not altered in the presence of XopB. However, XopB inhibited the flg22-triggered burst of reactive oxygen species (ROS). Consequently, the transcript accumulation of AtOXI1, a ROS-dependent marker gene, was reduced in xopB-expressing Arabidopsis plants as well as callose deposition. The lower ROS production correlated with a low level of basal and flg22-triggered expression of apoplastic peroxidases and the NADPH oxidase RBOHD. Conversely, deletion of xopB in Xcv caused a higher production of ROS in leaves of susceptible pepper plants. Together our results demonstrate that XopB modulates ROS responses and might thereby compromise plant defence. PMID:27398933

  8. The Xanthomonas campestris pv. vesicatoria Type-3 Effector XopB Inhibits Plant Defence Responses by Interfering with ROS Production

    PubMed Central

    Priller, Johannes Peter Roman; Reid, Stephen; Konein, Patrick; Dietrich, Petra

    2016-01-01

    The bacterial pathogen Xanthomonas campestris pv. vesicatoria 85–10 (Xcv) translocates about 30 type-3 effector proteins (T3Es) into pepper plants (Capsicum annuum) to suppress plant immune responses. Among them is XopB which interferes with PTI, ETI and sugar-mediated defence responses, but the underlying molecular mechanisms and direct targets are unknown so far. Here, we examined the XopB-mediated suppression of plant defence responses in more detail. Infection of susceptible pepper plants with Xcv lacking xopB resulted in delayed symptom development compared to Xcv wild type infection concomitant with an increased formation of salicylic acid (SA) and expression of pathogenesis-related (PR) genes. Expression of xopB in Arabidopsis thaliana promoted the growth of the virulent Pseudomonas syringae pv. tomato (Pst) DC3000 strain. This was paralleled by a decreased SA-pool and a lower induction of SA-dependent PR gene expression. The expression pattern of early flg22-responsive marker genes indicated that MAPK signalling was not altered in the presence of XopB. However, XopB inhibited the flg22-triggered burst of reactive oxygen species (ROS). Consequently, the transcript accumulation of AtOXI1, a ROS-dependent marker gene, was reduced in xopB-expressing Arabidopsis plants as well as callose deposition. The lower ROS production correlated with a low level of basal and flg22-triggered expression of apoplastic peroxidases and the NADPH oxidase RBOHD. Conversely, deletion of xopB in Xcv caused a higher production of ROS in leaves of susceptible pepper plants. Together our results demonstrate that XopB modulates ROS responses and might thereby compromise plant defence. PMID:27398933

  9. Dehydrosilybin attenuates the production of ROS in rat cardiomyocyte mitochondria with an uncoupler-like mechanism.

    PubMed

    Gabrielová, Eva; Jabůrek, Martin; Gažák, Radek; Vostálová, Jitka; Ježek, Jan; Křen, Vladimír; Modrianský, Martin

    2010-12-01

    Reactive oxygen species (ROS) originating from mitochondria are perceived as a factor contributing to cell aging and means have been sought to attenuate ROS formation with the aim of extending the cell lifespan. Silybin and dehydrosilybin, two polyphenolic compounds, display a plethora of biological effects generally ascribed to their known antioxidant capacity. When investigating the cytoprotective effects of these two compounds in the primary cell cultures of neonatal rat cardiomyocytes, we noted the ability of dehydrosilybin to de-energize the cells by monitoring JC-1 fluorescence. Experiments evaluating oxygen consumption and membrane potential revealed that dehydrosilybin uncouples the respiration of isolated rat heart mitochondria albeit with a much lower potency than synthetic uncouplers. Furthermore, dehydrosilybin revealed a very high potency in suppressing ROS formation in isolated rat heart mitochondria with IC(50) = 0.15 μM. It is far more effective than its effect in a purely chemical system generating superoxide or in cells capable of oxidative burst, where the IC(50) for dehydrosilybin exceeds 50 μM. Dehydrosilybin also attenuated ROS formation caused by rotenone in the primary cultures of neonatal rat cardiomyocytes. We infer that the apparent uncoupler-like activity of dehydrosilybin is the basis of its ROS modulation effect in neonatal rat cardiomyocytes and leads us to propose a hypothesis on natural ischemia preconditioning by dietary polyphenols. PMID:21153691

  10. ROS Production Is Essential for the Apoptotic Function of E2F1 in Pheochromocytoma and Neuroblastoma Cell Lines

    PubMed Central

    Espada, Lilia; Meo-Evoli, Nathalie; Sancho, Patricia; Real, Sebastian; Fabregat, Isabel; Ambrosio, Santiago; Tauler, Albert

    2012-01-01

    In this study we demonstrate that accumulation of reactive oxygen species (ROS) is essential for E2F1 mediated apoptosis in ER-E2F1 PC12 pheochromocytoma, and SH-SY5Y and SK-N-JD neuroblastoma stable cell lines. In these cells, the ER-E2F1 fusion protein is expressed in the cytosol; the addition of 4-hydroxytamoxifen (OHT) induces its translocation to the nucleus and activation of E2F1target genes. Previously we demonstrated that, in ER-E2F1 PC12 cells, OHT treatment induced apoptosis through activation of caspase-3. Here we show that caspase-8 activity did not change upon treatment with OHT. Moreover, over-expression of Bcl-xL arrested OHT-induced apoptosis; by contrast, over-expression of c-FLIP, did not have any effect on OHT-induced apoptosis. OHT addition induces BimL expression, its translocation to mitochondria and activation of Bax, which is paralleled by diminished mitochondrial enrichment of Bcl-xL. Treatment with a Bax-inhibitory peptide reduced OHT-induced apoptosis. These results point out the essential role of mitochondria on the apoptotic process driven by E2F1. ROS accumulation followed E2F1 induction and treatment with the antioxidant N-acetylcysteine, inhibited E2F1-induced Bax translocation to mitochondria and subsequent apoptosis. The role of ROS in mediating OHT-induced apoptosis was also studied in two neuroblastoma cell lines, SH-SY5Y and SK-N-JD. In SH-SY5Y cells, activation of E2F1 by the addition of OHT induced ROS production and apoptosis, whereas over-expression of E2F1 in SK-N-JD cells failed to induce either response. Transcriptional profiling revealed that many of the genes responsible for scavenging ROS were down-regulated following E2F1-induction in SH-SY5Y, but not in SK-N-JD cells. Finally, inhibition of GSK3β blocked ROS production, Bax activation and the down regulation of ROS scavenging genes. These findings provide an explanation for the apparent contradictory role of E2F1 as an apoptotic agent versus a cell cycle activator

  11. Iminophosphorane-organogold(III) complexes induce cell death through mitochondrial ROS production.

    PubMed

    Vela, Laura; Contel, María; Palomera, Luis; Azaceta, Gemma; Marzo, Isabel

    2011-10-01

    Gold compounds are being investigated as potential antitumor drugs. Some gold(III) derivatives have been shown to induce cell death in solid tumors but their mechanism of action differs from that of cisplatin, since most of these compounds do not bind to DNA. We have explored cellular events triggered by three different iminophosphorane-organogold(III) compounds in leukemia cells (a neutral compound with two chloride ligands [Au{κ(2)-C,N-C(6)H(4)(PPh(2)=N(C(6)H(5))-2}Cl(2)] 1, and two cationic compounds with either a dithiocarbamate ligand [Au{κ(2)-C,N-C(6)H(4)(PPh(2)=N(C(6)H(5))-2}(S(2)CN-Me(2))]PF(6)2, or a water-soluble phosphine and a chloride ligand [Au{κ(2)-C,N-C(6)H(4)(PPh(2)=N(C(6)H(5))-2}(P{Cp(m-C(6)H(4)-SO(3)Na)(2)}(3)) Cl]PF(6)3). All three compounds showed higher toxicity against leukemia cells when compared to normal T-lymphocytes. Compounds 1 and 2 induced both necrosis and apoptosis, while 3 was mainly apoptotic. Necrotic cell death induced by 1 and 2 was Bax/Bak- and caspase-independent, while apoptosis induced by 3 was Bax/Bak-dependent. Reactive oxygen species (ROS) production at the mitochondrial level was a critical step in the antitumor effect of these compounds. PMID:21864808

  12. Iminophosphorane-organogold(III) complexes induce cell death through mitochondrial ROS production

    PubMed Central

    Vela, Laura; Contel, María; Palomera, Luis; Azaceta, Gemma; Marzo, Isabel

    2011-01-01

    Gold compounds are being investigated as potential antitumor drugs. Some gold(III) derivatives have shown to induce cell death in solid tumors but their mechanism of action differs from that of cisplatin, since most of these compounds do not bind to DNA. We have explored cellular events triggered by three different iminophosphorane-organo gold(III) compounds in leukemia cells (a neutral compound with two chloride ligands [Au{κ2-C,N-C6H4(PPh2=N(C6H5)-2}Cl2] 1, and two cationic compounds with either a dithiocarbamate ligand [Au{κ2-C,N-C6H4(PPh2=N(C6H5)-2}(S2CN-Me2)]PF6 2, or a water-soluble phosphine and a chloride ligand [Au{κ2-C,N-C6H4(PPh2=N(C6H5)-2}(P{Cp(m-C6H4-SO3Na)2}3) Cl]PF6 3). All three compounds showed higher toxicity against leukemia cells when compared to normal T-lymphocytes. Compounds 1 and 2 induced both necrosis and apoptosis, while 3 was mainly apoptotic. Necrotic cell death induced by 1 and 2 was Bax/Bak- and caspase-independent, while apoptosis induced by 3 was Bax/Bak-dependent. Reactive oxygen species (ROS) production at the mitochondrial level was a critical step in the antitumor effect of these compounds. PMID:21864808

  13. The adhesion GPCR BAI1 mediates macrophage ROS production and microbicidal activity against Gram-negative bacteria

    PubMed Central

    Billings, Emily A.; Lee, Chang Sup; Owen, Katherine A.; D’Souza, Ryan S.; Ravichandran, Kodi S.; Casanova, James E.

    2016-01-01

    The detection of microbes and initiation of an innate immune response occur through pattern recognition receptors (PRRs), which are critical for the production of inflammatory cytokines and activation of the cellular microbicidal machinery. In particular, the production of reactive oxygen species (ROS) by the NADPH oxidase complex is a critical component of the macrophage bactericidal machinery. We previously characterized brain-specific angiogenesis inhibitor 1 (BAI1), a member of the adhesion family of G protein (heterotrimeric guanine nucleotide–binding protein)–coupled receptors (GPCRs), as a PRR that mediates the selective phagocytic uptake of Gram-negative bacteria by macrophages. We showed that BAI1 promoted phagosomal ROS production through activation of the Rho family guanosine triphosphatase (GTPase) Rac1, thereby stimulating NADPH oxidase activity. Primary BAI1-deficient macrophages exhibited attenuated Rac GTPase activity and reduced ROS production in response to several Gram-negative bacteria, resulting in impaired microbicidal activity. Furthermore, in a peritoneal infection model, BAI1-deficient mice exhibited increased susceptibility to death by bacterial challenge because of impaired bacterial clearance. Together, these findings suggest that BAI1 mediates the clearance of Gram-negative bacteria by stimulating both phagocytosis and NADPH oxidase activation, thereby coupling bacterial detection to the cellular microbicidal machinery. PMID:26838550

  14. Arylhydrocarbon receptor (AhR) activation in airway epithelial cells induces MUC5AC via reactive oxygen species (ROS) production.

    PubMed

    Chiba, Takahito; Uchi, Hiroshi; Tsuji, Gaku; Gondo, Hisaki; Moroi, Yoichi; Furue, Masutaka

    2011-02-01

    The dioxins and dioxin-like compounds in cigarette smoke regulate various immunological responses via the arylhydrocarbon receptor (AhR). These environmental toxicants are known to cause bronchitis, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. Recent studies have demonstrated that AhR activation upregulates the expression of mucin 5AC, oligomeric mucus/gel-forming (MUC5AC) in the airway epithelial cell line. However, the mechanism for the production of mucin has not been clarified. In this study, we investigated the role and pathway of AhR in airway epithelial cells by using selective agonists and antagonists. After stimulation with or without benzopyrene (B[a]P), an AhR agonist, MUC5AC expression was measured by real-time RT-PCR. The mechanism of AhR-induced MUC5AC expression in airway epithelial cells was studied in terms of the production of cytokine and reactive oxygen species (ROS). Treatment with B[a]P increased ROS generation in NCI-H₂₉₂ cells. Furthermore, B[a]P-induced MUC5AC upregulation and mucin production were inhibited by AhR siRNA or the use of an antioxidative agent. These results suggest that the AhR-induced increase of mucin production is partially mediated by ROS generation. An antioxidant therapy approach may help to cure AhR-induced mucus hypersecretory diseases. PMID:20709182

  15. ROS Hexapod

    NASA Technical Reports Server (NTRS)

    Davis, Kirsch; Bankieris, Derek

    2016-01-01

    As an intern project for NASA Johnson Space Center (JSC), my job was to familiarize myself and operate a Robotics Operating System (ROS). The project outcome will convert existing software assets into ROS using nodes, enabling a robotic Hexapod to communicate and to be functional and controlled by an existing PlayStation 3 (PS3) controller. Existing control algorithms and current libraries have no ROS capabilities within the Hexapod C++ source code. Conversion of C++ codes to ROS will enable existing code to be compatible with ROS, and will be controlled using existing PS3 controller. Furthermore, my job description is to design ROS messages and script programs which will enable assets to participate in the ROS ecosystem. In addition, an open source software (IDE) Arduino board will be integrated in the ecosystem with designing circuitry on a breadboard to add additional behavior with push buttons, potentiometers and other simple elements in the electrical circuitry. Other projects with the Arduino will be a GPS module digital clock that will run off 22 satellites to show accurate real time using a GPS signal and internal patch antenna to communicate with satellites.

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

    SciTech Connect

    Hu Fen; Sun Wenwu; Zhao Xiao Ting; Cui Zongjie Yang Wenxiu

    2008-05-16

    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 ([Ca{sup 2+}]{sub c}) and reactive oxygen species (ROS) production in synoviocytes isolated from a rat model of collagen-induced arthritis. The increases in both [Ca{sup 2+}]{sub 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 [Ca{sup 2+}]{sub c} elevation, ROS production, and mitochondrial membrane depolarization.

  17. Enhanced ROS production and oxidative damage in subcutaneous white adipose tissue mitochondria in obese and type 2 diabetes subjects.

    PubMed

    Chattopadhyay, Mrittika; Khemka, Vineet Kumar; Chatterjee, Gargi; Ganguly, Anirban; Mukhopadhyay, Satinath; Chakrabarti, Sasanka

    2015-01-01

    Oxidative stress in the insulin target tissues has been implicated in the pathophysiology of type 2 diabetes. The study has examined the oxidative stress parameters in the mitochondria of subcutaneous white adipose tissue from obese and non-obese subjects with or without type 2 diabetes. An accumulation of protein carbonyls, fluorescent lipid peroxidation products, and malondialdehyde occurs in the adipose tissue mitochondria of obese type 2 diabetic, non-diabetic obese, and non-obese diabetic subjects with the maximum increase noticed in the obese type 2 diabetes patients and the minimum in non-obese type 2 diabetics. The mitochondria from obese type 2 diabetics, non-diabetic obese, and non-obese type 2 diabetics also produce significantly more reactive oxygen species (ROS) in vitro compared to those of controls, and apparently the mitochondrial ROS production rate in each group is proportional to the respective load of oxidative damage markers. Likewise, the mitochondrial antioxidant enzymes like superoxide dismutase and glutathione peroxidase show decreased activities most markedly in obese type 2 diabetes subjects and to a lesser degree in non-obese type 2 diabetes or non-diabetic obese subjects in comparison to control. The results imply that mitochondrial dysfunction with enhanced ROS production may contribute to the metabolic abnormality of adipose tissue in obesity and diabetes. PMID:25312902

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

    EPA Science Inventory

    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...

  19. Perfluorooctane sulfonate (PFOS) induces reactive oxygen species (ROS) production in human microvascular endothelial cells: role in endothelial permeability

    PubMed Central

    Qian, Yong; Ducatman, Alan; Ward, Rebecca; Leonard, Steve; Bukowski, Valerie; Guo, Nancy Lan; Shi, Xianglin; Vallyathan, Val; Castranova, Vincent

    2011-01-01

    Perfluorooctane sulfonate (PFOS) is a member of perfluoroalkyl acids (PFAA) containing an 8-carbon backbone. PFOS is a man-made chemical with carbon-fluorine bonds that are one of the strongest in organic chemistry and widely used in industry. Human occupational and environmental exposure to PFOS occurs globally. PFOS is non-biodegradable and persistent in the human body and environment. In this study, data demonstrated that exposure of human microvascular endothelial cells (HMVEC) to PFOS induced the production of reactive oxygen species (ROS) at both high and low concentrations. Morphologically, it was found that exposure to PFOS induced actin filament remodeling and endothelial permeability changes in HMVEC. Furthermore, data demonstrated the production of ROS plays a regulatory role in PFOS-induced actin filament remodeling and the increase in endothelial permeability. Our results indicate that the generation of ROS may play a role in PFOS-induced aberrations of the endothelial permeability barrier. The results generated from this study may provide a new insight into the potential adverse effects of PFOS exposure on humans at the cellular level. PMID:20391123

  20. Carnosine inhibits KRAS-mediated HCT116 proliferation by affecting ATP and ROS production.

    PubMed

    Iovine, Barbara; Iannella, Maria Luigia; Nocella, Francesca; Pricolo, Maria Rosaria; Bevilacqua, Maria Assunta

    2012-02-28

    Carnosine is a natural dipeptide that has generated particular interest for its antioxidant, anti-aging and especially for its antiproliferative properties. In this study, we demonstrate that carnosine inhibits the proliferation of human HCT116 colon cancer cells. In this cell line, the activating KRAS mutation induces mitochondrial ROS, the signaling molecules for cell proliferation. We observed that 50-100 mM carnosine decreases ATP and ROS concentration and induces cell cycle arrest in G1 phase. In HCT116 cells these effects are related to decreased ERK1/2 phosphorylation and increased p21waf1 protein. Our findings support the concept that carnosine could inhibit HCT116 cell growth via its antioxidant activity and its ability to affect glycolysis. PMID:22137144

  1. ROS Production via P2Y1-PKC-NOX2 Is Triggered by Extracellular ATP after Electrical Stimulation of Skeletal Muscle Cells

    PubMed Central

    Díaz-Vegas, Alexis; Campos, Cristian A.; Contreras-Ferrat, Ariel; Casas, Mariana; Buvinic, Sonja; Jaimovich, Enrique; Espinosa, Alejandra

    2015-01-01

    During exercise, skeletal muscle produces reactive oxygen species (ROS) via NADPH oxidase (NOX2) while inducing cellular adaptations associated with contractile activity. The signals involved in this mechanism are still a matter of study. ATP is released from skeletal muscle during electrical stimulation and can autocrinely signal through purinergic receptors; we searched for an influence of this signal in ROS production. The aim of this work was to characterize ROS production induced by electrical stimulation and extracellular ATP. ROS production was measured using two alternative probes; chloromethyl-2,7- dichlorodihydrofluorescein diacetate or electroporation to express the hydrogen peroxide-sensitive protein Hyper. Electrical stimulation (ES) triggered a transient ROS increase in muscle fibers which was mimicked by extracellular ATP and was prevented by both carbenoxolone and suramin; antagonists of pannexin channel and purinergic receptors respectively. In addition, transient ROS increase was prevented by apyrase, an ecto-nucleotidase. MRS2365, a P2Y1 receptor agonist, induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal, similar to the one seen when using ATP plus MRS2179, an antagonist of P2Y1. Protein kinase C (PKC) inhibitors also blocked ES-induced ROS production. Our results indicate that physiological levels of electrical stimulation induce ROS production in skeletal muscle cells through release of extracellular ATP and activation of P2Y1 receptors. Use of selective NOX2 and PKC inhibitors suggests that ROS production induced by ES or extracellular ATP is mediated by NOX2 activated by PKC. PMID:26053483

  2. ROS Production via P2Y1-PKC-NOX2 Is Triggered by Extracellular ATP after Electrical Stimulation of Skeletal Muscle Cells.

    PubMed

    Díaz-Vegas, Alexis; Campos, Cristian A; Contreras-Ferrat, Ariel; Casas, Mariana; Buvinic, Sonja; Jaimovich, Enrique; Espinosa, Alejandra

    2015-01-01

    During exercise, skeletal muscle produces reactive oxygen species (ROS) via NADPH oxidase (NOX2) while inducing cellular adaptations associated with contractile activity. The signals involved in this mechanism are still a matter of study. ATP is released from skeletal muscle during electrical stimulation and can autocrinely signal through purinergic receptors; we searched for an influence of this signal in ROS production. The aim of this work was to characterize ROS production induced by electrical stimulation and extracellular ATP. ROS production was measured using two alternative probes; chloromethyl-2,7- dichlorodihydrofluorescein diacetate or electroporation to express the hydrogen peroxide-sensitive protein Hyper. Electrical stimulation (ES) triggered a transient ROS increase in muscle fibers which was mimicked by extracellular ATP and was prevented by both carbenoxolone and suramin; antagonists of pannexin channel and purinergic receptors respectively. In addition, transient ROS increase was prevented by apyrase, an ecto-nucleotidase. MRS2365, a P2Y1 receptor agonist, induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal, similar to the one seen when using ATP plus MRS2179, an antagonist of P2Y1. Protein kinase C (PKC) inhibitors also blocked ES-induced ROS production. Our results indicate that physiological levels of electrical stimulation induce ROS production in skeletal muscle cells through release of extracellular ATP and activation of P2Y1 receptors. Use of selective NOX2 and PKC inhibitors suggests that ROS production induced by ES or extracellular ATP is mediated by NOX2 activated by PKC. PMID:26053483

  3. Reactive Oxygen Species (Ros-Induced) Ros Release

    PubMed Central

    Zorov, Dmitry B.; Filburn, Charles R.; Klotz, Lars-Oliver; Zweier, Jay L.; Sollott, Steven J.

    2000-01-01

    We sought to understand the relationship between reactive oxygen species (ROS) and the mitochondrial permeability transition (MPT) in cardiac myocytes based on the observation of increased ROS production at sites of spontaneously deenergized mitochondria. We devised a new model enabling incremental ROS accumulation in individual mitochondria in isolated cardiac myocytes via photoactivation of tetramethylrhodamine derivatives, which also served to report the mitochondrial transmembrane potential, ΔΨ. This ROS accumulation reproducibly triggered abrupt (and sometimes reversible) mitochondrial depolarization. This phenomenon was ascribed to MPT induction because (a) bongkrekic acid prevented it and (b) mitochondria became permeable for calcein (∼620 daltons) concurrently with depolarization. These photodynamically produced “triggering” ROS caused the MPT induction, as the ROS scavenger Trolox prevented it. The time required for triggering ROS to induce the MPT was dependent on intrinsic cellular ROS-scavenging redox mechanisms, particularly glutathione. MPT induction caused by triggering ROS coincided with a burst of mitochondrial ROS generation, as measured by dichlorofluorescein fluorescence, which we have termed mitochondrial “ROS-induced ROS release” (RIRR). This MPT induction/RIRR phenomenon in cardiac myocytes often occurred synchronously and reversibly among long chains of adjacent mitochondria demonstrating apparent cooperativity. The observed link between MPT and RIRR could be a fundamental phenomenon in mitochondrial and cell biology. PMID:11015441

  4. Hyperglycemia Induces Cellular Hypoxia through Production of Mitochondrial ROS Followed by Suppression of Aquaporin-1

    PubMed Central

    Sada, Kiminori; Nishikawa, Takeshi; Kukidome, Daisuke; Yoshinaga, Tomoaki; Kajihara, Nobuhiro; Sonoda, Kazuhiro; Senokuchi, Takafumi; Motoshima, Hiroyuki; Matsumura, Takeshi; Araki, Eiichi

    2016-01-01

    We previously proposed that hyperglycemia-induced mitochondrial reactive oxygen species (mtROS) generation is a key event in the development of diabetic complications. Interestingly, some common aspects exist between hyperglycemia and hypoxia-induced phenomena. Thus, hyperglycemia may induce cellular hypoxia, and this phenomenon may also be involved in the pathogenesis of diabetic complications. In endothelial cells (ECs), cellular hypoxia increased after incubation with high glucose (HG). A similar phenomenon was observed in glomeruli of diabetic mice. HG-induced cellular hypoxia was suppressed by mitochondria blockades or manganese superoxide dismutase (MnSOD) overexpression, which is a specific SOD for mtROS. Overexpression of MnSOD also increased the expression of aquaporin-1 (AQP1), a water and oxygen channel. AQP1 overexpression in ECs suppressed hyperglycemia-induced cellular hypoxia, endothelin-1 and fibronectin overproduction, and apoptosis. Therefore, hyperglycemia-induced cellular hypoxia and mtROS generation may promote hyperglycemic damage in a coordinated manner. PMID:27383386

  5. HSP27 Inhibits Homocysteine-Induced Endothelial Apoptosis by Modulation of ROS Production and Mitochondrial Caspase-Dependent Apoptotic Pathway

    PubMed Central

    Tian, Xin; Zhao, Lei; Song, Xianjing; Yan, Youyou; Liu, Ning; Li, Tianyi; Yan, Bingdi

    2016-01-01

    Objectives. Elevated plasma homocysteine (Hcy) could lead to endothelial dysfunction and is viewed as an independent risk factor for atherosclerosis. Heat shock protein 27 (HSP27), a small heat shock protein, is reported to exert protective effect against atherosclerosis. This study aims to investigate the protective effect of HSP27 against Hcy-induced endothelial cell apoptosis in human umbilical vein endothelial cells (HUVECs) and to determine the underlying mechanisms. Methods. Apoptosis, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) of normal or HSP27-overexpressing HUVECs in the presence of Hcy were analyzed by flow cytometry. The mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Results. We found that Hcy could induce cell apoptosis with corresponding decrease of nitric oxide (NO) level, increase of endothelin-1 (ET-1), intracellular adhesion molecule-1 (ICAM-1), vascular cellular adhesion molecule-1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1) levels, elevation of ROS, and dissipation of MMP. In addition, HSP27 could protect the cell against Hcy-induced apoptosis and inhibit the effect of Hcy on HUVECs. Furthermore, HSP27 could increase the ratio of Bcl-2/Bax and inhibit caspase-3 activity. Conclusions. Therefore, we concluded that HSP27 played a protective role against Hcy-induced endothelial apoptosis through modulation of ROS production and the mitochondrial caspase-dependent apoptotic pathway. PMID:27190988

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

    PubMed

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

    2014-01-01

    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

  7. Tea polyphenols alleviate high fat and high glucose-induced endothelial hyperpermeability by attenuating ROS production via NADPH oxidase pathway

    PubMed Central

    2014-01-01

    Background Hyperglycemia-induced endothelial hyperpermeability is crucial to cardiovascular disorders and macro-vascular complications in diabetes mellitus. The objective of this study is to investigate the effects of green tea polyphenols (GTPs) on endothelial hyperpermeability and the role of nicotinamide adenine dinucleotide phosphate (NADPH) pathway. Methods Male Wistar rats fed on a high fat diet (HF) were treated with GTPs (0, 0.8, 1.6, 3.2 g/L in drinking water) for 26 weeks. Bovine aortic endothelial cells (BAECs) were treated with high glucose (HG, 33 mmol/L) and GTPs (0.0, 0.4, or 4 μg/mL) for 24 hours in vitro. The endothelial permeabilities in rat aorta and monolayer BAECs were measured by Evans blue injection method and efflux of fluorescein isothiocyanate (FITC)-dextran, respectively. The reactive oxygen species (ROS) levels in rat aorta and monolayer BAECs were measured by dihydroethidium (DHE) and 2′, 7′-dichloro-fluorescein diacetate (DCFH-DA) fluorescent probe, respectively. Protein levels of NADPH oxidase subunits were determined by Western-blot. Results HF diet-fed increased the endothelial permeability and ROS levels in rat aorta while HG treatments increased the endothelial permeability and ROS levels in cultured BAECs. Co-treatment with GTPs alleviated those changes both in vivo and in vitro. In in vitro studies, GTPs treatments protected against the HG-induced over-expressions of p22phox and p67phox. Diphenylene iodonium chloride (DPI), an inhibitor of NADPH oxidase, alleviated the hyperpermeability induced by HG. Conclusions GTPs could alleviate endothelial hyperpermeabilities in HF diet-fed rat aorta and in HG treated BAECs. The decrease of ROS production resulting from down-regulation of NADPH oxidase contributed to the alleviation of endothelial hyperpermeability. PMID:24580748

  8. Effects of Mountain Ultra-Marathon Running on ROS Production and Oxidative Damage by Micro-Invasive Analytic Techniques

    PubMed Central

    Mrakic-Sposta, Simona; Gussoni, Maristella; Moretti, Sarah; Pratali, Lorenza; Giardini, Guido; Tacchini, Philippe; Dellanoce, Cinzia; Tonacci, Alessandro; Mastorci, Francesca; Borghini, Andrea; Montorsi, Michela; Vezzoli, Alessandra

    2015-01-01

    Purpose Aiming to gain a detailed insight into the physiological mechanisms involved under extreme conditions, a group of experienced ultra-marathon runners, performing the mountain Tor des Géants® ultra-marathon: 330 km trail-run in Valle d’Aosta, 24000 m of positive and negative elevation changes, was monitored. ROS production rate, antioxidant capacity, oxidative damage and inflammation markers were assessed, adopting micro-invasive analytic techniques. Methods Forty-six male athletes (45.04±8.75 yr, 72.6±8.4 kg, 1.76±0.05 m) were tested. Capillary blood and urine were collected before (Pre-), in the middle (Middle-) and immediately after (Post-) Race. Samples were analyzed for: Reactive Oxygen Species (ROS) production by Electron Paramagnetic Resonance; Antioxidant Capacity by Electrochemistry; oxidative damage (8-hydroxy-2-deoxy Guanosine: 8-OH-dG; 8-isoprostane: 8-isoPGF2α) and nitric oxide metabolites by enzymatic assays; inflammatory biomarkers (plasma and urine interleukin-6: IL-6-P and IL-6-U) by enzyme-linked immunosorbent assays (ELISA); Creatinine and Neopterin by HPLC, hematologic (lactate, glucose and hematocrit) and urine parameters by standard analyses. Results Twenty-five athletes finished the race, while twenty-one dropped out of it. A significant increase (Post-Race vs Pre) of the ROS production rate (2.20±0.27 vs 1.65±0.22 μmol.min-1), oxidative damage biomarkers (8-OH-dG: 6.32±2.38 vs 4.16±1.25 ng.mg-1 Creatinine and 8-isoPGF2α: 1404.0±518.30 vs 822.51±448.91 pg.mg-1Creatinine), inflammatory state (IL-6-P: 66.42±36.92 vs 1.29±0.54 pg.mL-1 and IL-6-U: 1.33±0.56 vs 0.71±0.17 pg.mL1) and lactate production (+190%), associated with a decrease of both antioxidant capacity (-7%) and renal function (i.e. Creatinine level +76%) was found. Conclusions The used micro-invasive analytic methods allowed us to perform most of them before, during and immediately after the race directly in the field, by passing the need of storing and

  9. Kaempferol inhibits the production of ROS to modulate OPN-αvβ3 integrin pathway in HUVECs.

    PubMed

    Xiao, Hong-Bo; Lu, Xiang-Yang; Liu, Zi-Kui; Luo, Zhi-Feng

    2016-06-01

    In the present study, we tested the hypothesis that aldosterone regulates osteopontin (OPN)-related signaling pathways to promote nuclear factor κB (NF-κB) activation in primary human umbilical vein endothelial cells (HUVECs) and that kaempferol, a flavonoid compound, blocks those changes. Aldosterone induced productions of reactive oxygen species (ROS), OPN, interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) and expression of nicotinamide adenine dinucleotide phosphate-oxidase 4 (Nox4), NF-κB, OPN, alphavbeta3 (αvβ3) integrin, and inhibitor of NF-κB alpha phosphorylation (P-IκBα) in HUVEC. HUVECs were pretreated with kaempferol (0, 1, 3, or 10 μM) for 1 h and exposed to aldosterone (10(-6) M) for 24 h. Kaempferol reduced ROS, OPN, NF-κB, IL-6, and TNF-α levels; Nox4, αvβ3 integrin; and P-IκBα expressions. The effect of aldosterone was also abrogated by spironolactone (10(-6) M). In addition, vitamin C (20 mmol/L) reduced ROS production. Vitamin C and LM609 (10 μg/mL) treatment decreased expressions of OPN, αvβ3 integrin, and NF-κB (P < 0.05 or P < 0.01). The present results suggest that kaempferol may modulate OPN-αvβ3 integrin pathway to inhibit NF-κB activation in HUVECs. PMID:27000882

  10. Echinacoside Protects against 6-Hydroxydopamine-Induced Mitochondrial Dysfunction and Inflammatory Responses in PC12 Cells via Reducing ROS Production

    PubMed Central

    Wang, Yue-Hua; Xuan, Zhao-Hong; Tian, Shuo; Du, Guan-Hua

    2015-01-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive loss of dopaminergic (DA) neurons at the substantia nigra. Mitochondrial dysfunction and inflammatory responses are involved in the mechanism of cell damage in PD. 6-Hydroxydopamine (6-OHDA), a dopamine analog, specifically damages dopaminergic neurons. Echinacoside (ECH) is a phenylethanoid glycoside isolated from the stems of Cistanche salsa, showing a variety of neuroprotective effects in previous studies. The present study was to investigate its effect against 6-OHDA-induced neurotoxicity and possible mechanisms in PC12 cells. The results showed that 6-OHDA reduced cell viability, decreased oxidation-reduction activity, decreased mitochondrial membrane potential, and induced mitochondria-mediated apoptosis compared with untreated PC12 cells. However, echinacoside treatment significantly attenuated these changes induced by 6-OHDA. In addition, echinacoside also could significantly alleviate the inflammatory responses induced by 6-OHDA. Further research showed that echinacoside could reduce 6-OHDA-induced ROS production in PC12 cells. These results suggest that the underlying mechanism of echinacoside against 6-OHDA-induced neurotoxicity may be involve in attenuating mitochondrial dysfunction and inflammatory responses by reducing ROS production. PMID:25788961

  11. COX5B Regulates MAVS-mediated Antiviral Signaling through Interaction with ATG5 and Repressing ROS Production

    PubMed Central

    Nie, Xuanli; Sun, Liwei; Tang, Tie-shan; Chen, Dahua; Sun, Qinmiao

    2012-01-01

    Innate antiviral immunity is the first line of the host defense system that rapidly detects invading viruses. Mitochondria function as platforms for innate antiviral signal transduction in mammals through the adaptor protein, MAVS. Excessive activation of MAVS-mediated antiviral signaling leads to dysfunction of mitochondria and cell apoptosis that likely causes the pathogenesis of autoimmunity. However, the mechanism of how MAVS is regulated at mitochondria remains unknown. Here we show that the Cytochrome c Oxidase (CcO) complex subunit COX5B physically interacts with MAVS and negatively regulates the MAVS-mediated antiviral pathway. Mechanistically, we find that while activation of MAVS leads to increased ROS production and COX5B expression, COX5B down-regulated MAVS signaling by repressing ROS production. Importantly, our study reveals that COX5B coordinates with the autophagy pathway to control MAVS aggregation, thereby balancing the antiviral signaling activity. Thus, our study provides novel insights into the link between mitochondrial electron transport system and the autophagy pathway in regulating innate antiviral immunity. PMID:23308066

  12. Febuxostat Inhibition of Endothelial-Bound XO: Implications for Targeting Vascular ROS Production

    PubMed Central

    Malik, Umair Z.; Hundley, Nicholas J.; Romero, Guillermo; Radi, Rafael; Freeman, Bruce A.; Tarpey, Margaret M.; Kelley, Eric E.

    2011-01-01

    Xanthine oxidase (XO) is a critical source of reactive oxygen species (ROS) that contribute to vascular inflammation. Binding of XO to vascular endothelial cell glycosaminoglycans (GAGs) results in significant resistance to inhibition by traditional pyrazolopyrimidine-based inhibitors such as allopurinol. Therefore, we compared the extent of XO inhibition (free and GAG-bound) by allopurinol to febuxostat, a newly approved nonpurine XO-specific inhibitor. In solution, febuxostat was 1000 fold more potent than allopurinol inhibition of XO-dependent uric acid formation (IC50 = 1.8 nM vs. 2.9 μM). Association of XO with heparin-Sepharose 6B (HS6B-XO) had minimal effect on inhibition of uric acid formation by febuxostat (IC50 = 4.4 nM) while further limiting the effect of allopurinol (IC50 = 64 μM). Kinetic analysis of febuxostat inhibition revealed Ki values of 0.96 nM (free) and 0.92 nM (HS6B-XO), confirming equivalent inhibition for both free and GAG-immobilized enzyme. When XO was bound to endothelial cell GAGs, complete enzyme inhibition was observed with 25 nM febuxostat, while no more than 80% inhibition was seen with either allopurinol or oxypurinol, even at concentrations above those tolerated clinically. The superior potency for inhibition of endothelium-associated XO is predictive of a significant role for febuxostat in investigating pathological states where XO-derived ROS are contributive and traditional XO inhibitors are only slightly effective. PMID:21554948

  13. Use of Commercial Dry Yeast Products Rich in Mannoproteins for White and Rosé Sparkling Wine Elaboration.

    PubMed

    Pérez-Magariño, Silvia; Martínez-Lapuente, Leticia; Bueno-Herrera, Marta; Ortega-Heras, Miriam; Guadalupe, Zenaida; Ayestarán, Belén

    2015-06-17

    In sparkling wines, mannoproteins released during yeast autolysis largely affect their final quality. This process is very slow and may take several months. The aim of this work was to study the effect of several commercial dry yeast autolysates on the chemical composition, foam, and sensory properties of white and rosé sparkling wines aged on lees for 9 months during two consecutive vintages. The addition of these products in the tirage phase did not affect either the content of phenolic compounds, amino acids, and biogenic amines or the foam properties. The commercial product with the highest mannoprotein content and the highest purity caused significant changes in the volatile composition of the wines and enhanced the fruity aromas in both Verdejo and Godello sparkling wines. PMID:26027899

  14. Glucose- and mannose-induced stomatal closure is mediated by ROS production, Ca(2+) and water channel in Vicia faba.

    PubMed

    Li, Yan; Xu, ShanShan; Gao, Jing; Pan, Sha; Wang, GenXuan

    2016-03-01

    Sugars act as vital signaling molecules that regulate plant growth, development and stress responses. However, the effects of sugars on stomatal movement have been unclear. In our study, we explored the effects of monosaccharides such as glucose and mannose on stomatal aperture. Here, we demonstrate that glucose and mannose trigger stomatal closure in a dose- and time-dependent manner in epidermal peels of broad bean (Vicia faba). Pharmacological studies revealed that glucose- and mannose-induced stomatal closure was almost completely inhibited by two reactive oxygen species (ROS) scavengers, catalase (CAT) and reduced glutathione (GSH), was significantly abolished by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI), whereas they were hardly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM). Furthermore, glucose- and mannose-induced stomatal closure was strongly inhibited by a Ca(2+) channel blocker, LaCl3 , a Ca(2+) chelator, ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid (EGTA) and two water channel blockers, HgCl2 and dimethyl sulfoxide (DMSO); whereas the inhibitory effects of the water channel blockers were essentially abolished by the reversing agent β-mercaptoethanol (β-ME). These results suggest that ROS production mainly via NADPH oxidases, Ca(2+) and water channels are involved in glucose- and mannose-induced stomatal closure. PMID:26046775

  15. Clostridium perfringens phospholipase C induced ROS production and cytotoxicity require PKC, MEK1 and NFκB activation.

    PubMed

    Monturiol-Gross, Laura; Flores-Díaz, Marietta; Pineda-Padilla, Maria Jose; Castro-Castro, Ana Cristina; Alape-Giron, Alberto

    2014-01-01

    Clostridium perfringens phospholipase C (CpPLC), also called α-toxin, is the most toxic extracellular enzyme produced by this bacteria and is essential for virulence in gas gangrene. At lytic concentrations, CpPLC causes membrane disruption, whereas at sublytic concentrations this toxin causes oxidative stress and activates the MEK/ERK pathway, which contributes to its cytotoxic and myotoxic effects. In the present work, the role of PKC, ERK 1/2 and NFκB signalling pathways in ROS generation induced by CpPLC and their contribution to CpPLC-induced cytotoxicity was evaluated. The results demonstrate that CpPLC induces ROS production through PKC, MEK/ERK and NFκB pathways, the latter being activated by the MEK/ERK signalling cascade. Inhibition of either of these signalling pathways prevents CpPLC's cytotoxic effect. In addition, it was demonstrated that NFκB inhibition leads to a significant reduction in the myotoxicity induced by intramuscular injection of CpPLC in mice. Understanding the role of these signalling pathways could lead towards developing rational therapeutic strategies aimed to reduce cell death during a clostridialmyonecrosis. PMID:24466113

  16. Clostridium perfringens Phospholipase C Induced ROS Production and Cytotoxicity Require PKC, MEK1 and NFκB Activation

    PubMed Central

    Monturiol-Gross, Laura; Flores-Díaz, Marietta; Pineda-Padilla, Maria Jose; Castro-Castro, Ana Cristina; Alape-Giron, Alberto

    2014-01-01

    Clostridium perfringens phospholipase C (CpPLC), also called α-toxin, is the most toxic extracellular enzyme produced by this bacteria and is essential for virulence in gas gangrene. At lytic concentrations, CpPLC causes membrane disruption, whereas at sublytic concentrations this toxin causes oxidative stress and activates the MEK/ERK pathway, which contributes to its cytotoxic and myotoxic effects. In the present work, the role of PKC, ERK 1/2 and NFκB signalling pathways in ROS generation induced by CpPLC and their contribution to CpPLC-induced cytotoxicity was evaluated. The results demonstrate that CpPLC induces ROS production through PKC, MEK/ERK and NFκB pathways, the latter being activated by the MEK/ERK signalling cascade. Inhibition of either of these signalling pathways prevents CpPLC's cytotoxic effect. In addition, it was demonstrated that NFκB inhibition leads to a significant reduction in the myotoxicity induced by intramuscular injection of CpPLC in mice. Understanding the role of these signalling pathways could lead towards developing rational therapeutic strategies aimed to reduce cell death during a clostridialmyonecrosis. PMID:24466113

  17. Cordyceps sinensis polysaccharide inhibits PDGF-BB-induced inflammation and ROS production in human mesangial cells.

    PubMed

    Wang, Ying; Wang, Yan; Liu, Dan; Wang, Wang; Zhao, Huan; Wang, Min; Yin, Hongping

    2015-07-10

    CPS-F, a polysaccharide derived from Cordyceps sinensis, is a potential anti-inflammatory and anti-oxidative agent. We demonstrated that CPS-F not only inhibits platelet-derived growth factor BB (PDGF-BB)-induced intracellular reactive oxygen species (ROS) generation, and up-regulation of tumor necrosis factor-α (TNF-α), TNF-α receptor 1 (TNFR1), and monocyte chemotactic protein-1 (MCP-1), but also acts synergistically in combination with MAPK/ERK inhibitor U0126 and PI3K/Akt inhibitor LY294002. Additionally, up-regulation of pro-inflammatory factors was reversed by use of a combination of CPS-F and NADPH oxidase (NOX) inhibitor diphenyleneiodonium chloride (DPI) or silencing of NOX1. Furthermore, CPS-F prevents the PDGF receptor β (PDGFRβ) promoter activity induced by PDGF-BB in transfected cells and ameliorates increased levels of TNF-α, TNFR1, and MCP-1 when PDGFRβ is silenced, thereby suggesting that CPS-F possesses a bidirectional regulatory function. Our findings suggest CPS-F may exert its therapeutic effect for the treatment of glomerulonephritis related to human mesangial cells (HMCs) through the ERK1/2/Akt pathways. PMID:25857968

  18. Optimizing Pulse Waveforms in Plasma Jets for Reactive Oxygen Species (ROS) Production

    NASA Astrophysics Data System (ADS)

    Norberg, Seth; Babaeva, Natalia Yu.; Kushner, Mark J.

    2012-10-01

    Reactive oxygen species (ROS) are desired in numerous applications from the destruction of harmful proteins and bacteria for sterilization in the medical field to taking advantage of the metastable characteristics of O2(^1δ) to transfer energy to other species. Advances in atmospheric pressure plasma jets in recent years show the possibility of using this application as a source of reactive oxygen species. In this paper, we report on results from a computational investigation of atmospheric pressure plasma jets in a dielectric barrier discharge (DBD) configuration. The computer model used in this study, nonPDPSIM, solves transport equations for charged and neutral species, Poisson's equation for the electric potential, the electron energy conservation equation for the electron temperature, and Navier-Stokes equations for the neutral gas flow. A Monte Carlo simulation is used to track sheath accelerated secondary electrons emitted from surfaces and the energy of ions incident onto surfaces. Rate coefficients and transport coefficients for the bulk plasma are obtained from local solutions of Boltzmann's equation for the electron energy distribution. Radiation transport is addressed using a Green's function approach. Various waveforms for the voltage source were examined in analogy to spiker-sustainer systems used at lower gas pressures.

  19. Quinone compounds regulate the level of ROS production by the NADPH oxidase Nox4.

    PubMed

    Nguyen, Minh Vu Chuong; Lardy, Bernard; Rousset, Francis; Hazane-Puch, Florence; Zhang, Leilei; Trocmé, Candice; Serrander, Lena; Krause, Karl-Heinz; Morel, Françoise

    2013-06-01

    NADPH oxidase Nox4 is expressed in a wide range of tissues and plays a role in cellular signaling by providing reactive oxygen species (ROS) as intracellular messengers. Nox4 oxidase activity is thought to be constitutive and regulated at the transcriptional level; however, we challenge this point of view and suggest that specific quinone derivatives could modulate this activity. In fact, we demonstrated a significant stimulation of Nox4 activity by 4 quinone derivatives (AA-861, tBuBHQ, tBuBQ, and duroquinone) observed in 3 different cellular models, HEK293E, T-REx™, and chondrocyte cell lines. Our results indicate that the effect is specific toward Nox4 versus Nox2. Furthermore, we showed that NAD(P)H:quinone oxidoreductase (NQO1) may participate in this stimulation. Interestingly, Nox4 activity is also stimulated by reducing agents that possibly act by reducing the disulfide bridge (Cys226, Cys270) located in the extracellular E-loop of Nox4. Such model of Nox4 activity regulation could provide new insight into the understanding of the molecular mechanism of the electron transfer through the enzyme, i.e., its potential redox regulation, and could also define new therapeutic targets in diseases in which quinones and Nox4 are implicated. PMID:23583257

  20. Mitochondrial Reactive Oxygen Species (ROS) and ROS-Induced ROS Release

    PubMed Central

    Zorov, Dmitry B.; Juhaszova, Magdalena; Sollott, Steven J.

    2014-01-01

    Byproducts of normal mitochondrial metabolism and homeostasis include the buildup of potentially damaging levels of reactive oxygen species (ROS), Ca2+, etc., which must be normalized. Evidence suggests that brief mitochondrial permeability transition pore (mPTP) openings play an important physiological role maintaining healthy mitochondria homeostasis. Adaptive and maladaptive responses to redox stress may involve mitochondrial channels such as mPTP and inner membrane anion channel (IMAC). Their activation causes intra- and intermitochondrial redox-environment changes leading to ROS release. This regenerative cycle of mitochondrial ROS formation and release was named ROS-induced ROS release (RIRR). Brief, reversible mPTP opening-associated ROS release apparently constitutes an adaptive housekeeping function by the timely release from mitochondria of accumulated potentially toxic levels of ROS (and Ca2+). At higher ROS levels, longer mPTP openings may release a ROS burst leading to destruction of mitochondria, and if propagated from mitochondrion to mitochondrion, of the cell itself. The destructive function of RIRR may serve a physiological role by removal of unwanted cells or damaged mitochondria, or cause the pathological elimination of vital and essential mitochondria and cells. The adaptive release of sufficient ROS into the vicinity of mitochondria may also activate local pools of redox-sensitive enzymes involved in protective signaling pathways that limit ischemic damage to mitochondria and cells in that area. Maladaptive mPTP- or IMAC-related RIRR may also be playing a role in aging. Because the mechanism of mitochondrial RIRR highlights the central role of mitochondria-formed ROS, we discuss all of the known ROS-producing sites (shown in vitro) and their relevance to the mitochondrial ROS production in vivo. PMID:24987008

  1. Intravenous Immunoglobulin Prevents Murine Antibody-Mediated Acute Lung Injury at the Level of Neutrophil Reactive Oxygen Species (ROS) Production

    PubMed Central

    Semple, John W.; Kim, Michael; Hou, Jing; McVey, Mark; Lee, Young Jin; Tabuchi, Arata; Kuebler, Wolfgang M.; Chai, Zhong-Wei; Lazarus, Alan H.

    2012-01-01

    Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-associated mortality that can occur with any type of transfusion and is thought to be primarily due to donor antibodies activating pulmonary neutrophils in recipients. Recently, a large prospective case controlled clinical study of cardiac surgery patients demonstrated that despite implementation of male donors, a high incidence of TRALI still occurred and suggested a need for additional interventions in susceptible patient populations. To examine if intravenous immunoglobulin (IVIg) may be effective, a murine model of antibody-mediated acute lung injury that approximates human TRALI was examined. When BALB/c mice were injected with the anti-major histocompatibility complex class I antibody 34-1-2s, mild shock (reduced rectal temperature) and respiratory distress (dyspnea) were observed and pre-treatment of the mice with 2 g/kg IVIg completely prevented these symptoms. To determine IVIg's usefulness to affect severe lung damage, SCID mice, previously shown to be hypersensitive to 34-1-2s were used. SCID mice treated with 34-1-2s underwent severe shock, lung damage (increased wet/dry ratios) and 40% mortality within 2 hours. Treatment with 2 g/kg IVIg 18 hours before 34-1-2s administration completely protected the mice from all adverse events. Treatment with IVIg after symptoms began also reduced lung damage and mortality. While the prophylactic IVIg administration did not affect 34-1-2s-induced pulmonary neutrophil accumulation, bone marrow-derived neutrophils from the IVIg-treated mice displayed no spontaneous ROS production nor could they be stimulated in vitro with fMLP or 34-1-2s. These results suggest that IVIg prevents murine antibody-mediated acute lung injury at the level of neutrophil ROS production and thus, alleviating tissue damage. PMID:22363629

  2. Influence of the surface charge of PLGA nanoparticles on their in vitro genotoxicity, cytotoxicity, ROS production and endocytosis.

    PubMed

    Platel, Anne; Carpentier, Rodolphe; Becart, Elodie; Mordacq, Gwendoline; Betbeder, Didier; Nesslany, Fabrice

    2016-03-01

    With the ongoing commercialization of nanotechnology products, human exposure to nanoparticles (NPs) is set to increase dramatically and an evaluation of their potential adverse effects is essential. Surface charge, among other physico-chemicals parameters, is a key criterion that should be considered when using a definition for nanomaterials in a regulatory context. It has recently been recognized as an important factor in determining the toxicity of NPs; however, a complete understanding of the mechanisms involved is still lacking. In this context, the aim of the present study was to investigate the influence of the surface charge modification of NPs on in vitro toxicity assays. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles bearing different surface charges, positive(+), neutral(n) or negative(-), were synthesized. In vitro genotoxicity assays (micronucleus and comet assays) coupled with an assessment of cytotoxicity, were performed in different cell lines (L5178Y mouse lymphoma cells, TK6 human B-lymphoblastoid cells and 16HBE14o- human bronchial epithelial cells). Reactive oxygen species (ROS) production and endocytosis studies were also performed. Our results showed that PLGA(+) NPs were cytotoxic. They are endocytosed by the clathrin pathway and induced ROS in the three cell lines. They led to chromosomal aberrations without primary DNA damage in 16HBE14o- cells, suggesting that aneuploidy may be considered as an important biomarker when assessing the genotoxic potential of NPs. Moreover, 16HBE14o- cells seem to be more suitable for the in vitro screening of inhaled NPs than the regulatory L5178Y and TK6 cells. PMID:26487569

  3. Fluoride Increases Superoxide Production and Impairs the Respiratory Chain in ROS 17/2.8 Osteoblastic Cells

    PubMed Central

    Fina, Brenda Lorena; Lombarte, Mercedes; Rigalli, Juan Pablo; Rigalli, Alfredo

    2014-01-01

    It is known that fluoride produces oxidative stress. Inflammation in bone tissue and an impairment of the respiratory chain of liver have been described in treatments with fluoride. Whether the impairment of the respiratory chain and oxidative stress are related is not known. The aim of this work was to study the effects of fluoride on the production of superoxide radical, the function of the respiratory chain and the increase in oxidative stress in ROS 17/2.8 osteoblastic cells. We measured the effect of fluoride (100 µM) on superoxide production, oxygen consumption, lipid peroxidation and antioxidant enzymes activities of cultured cells following the treatment with fluoride. Fluoride decreased oxygen consumption and increased superoxide production immediately after its addition. Furthermore, chronic treatment with fluoride increased oxidative stress status in osteoblastic cells. These results indicate that fluoride could damage bone tissue by inhibiting the respiratory chain, increasing the production of superoxide radicals and thus of the others reactive oxygen species. PMID:24964137

  4. Inclusion complexes of chloramphenicol with β-cyclodextrin and aminoacids as a way to increase drug solubility and modulate ROS production.

    PubMed

    Aiassa, Virginia; Zoppi, Ariana; Albesa, Inés; Longhi, Marcela R

    2015-05-01

    The aim of this study was to improve the solubility of chloramphenicol and reduce the production of reactive oxygen species (ROS) in leucocytes induced by this drug, using complexation. Multicomponent complexes were prepared by the addition of β-cyclodextrin with glycine or cysteine. Nuclear magnetic resonance and phase solubility studies provided information at the molecular level on the structure of the complexes and their association binding constants, respectively. In the solid state, all systems were extensively characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, thermal analysis and X-ray powder diffraction. Antimicrobial activity of inclusion complexes was investigated by agar diffusion methods. Finally ROS determination by chemiluminescence was used to investigate the effect of complex formation on the potential toxicity in human leucocytes. These studies revealed that multicomponent complexes can increase the aqueous solubility of chloramphenicol as well as reducing the stress by ROS production in leucocytes and maintaining its microbiological activity. PMID:25659705

  5. Pycnogenol® inhibits lipid accumulation in 3T3-L1 adipocytes with the modulation of reactive oxygen species (ROS) production associated with antioxidant enzyme responses.

    PubMed

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

    2012-03-01

    Pycnogenol® is a group of flavonoids with antioxidant effects. Adipogenesis is the process of adipocyte differentiation. It causes the increase of lipids as well as ROS (reactive oxygen species). Lipid accumulation and ROS production were determined in 3 T3-L1 adipocyte, and the effect of Pycnogenol® was evaluated. Lipid accumulation was elevated in adipocyte treated with hydrogen peroxide, one of the ROS. Pycnogenol® showed an inhibitory effect on the lipid accumulation and ROS production during the adipogenesis. We also investigated the molecular events associated with ROS production and lipid accumulation. Our results showed that Pycnogenol® inhibited the mRNA expression of pro-oxidant enzymes, such as NOX4 (NADPH (nicotinamide adenine dinucleotide phosphate hydrogen) oxidase 4), and the NADPH-producing G6PDH (glucose-6-phosphate dehydrogenase) enzyme. In addition, Pycnogenol® suppressed the mRNA abundance of adipogenic transcription factors, PPAR-γ (peroxisome proliferator-activated receptor γ) and C/EBP-α (CCAAT/enhancer binding protein α), and their target gene, aP2 (adipocyte protein 2) responsible for fatty acid transportation. On the other hand, Pycnogenol® increased the abundance of antioxidant proteins such as Cu/Zn-SOD (copper-zinc superoxide dismutase), Mn-SOD (manganese superoxide dismutase), GPx (glutathione peroxidase) and GR (glutathione reductase). Our results suggest that Pycnogenol® inhibits lipid accumulation and ROS production by regulating adipogenic gene expression and pro-/antioxidant enzyme responses in adipocytes. PMID:21796705

  6. 1,25(OH)2D3 inhibits high glucose-induced apoptosis and ROS production in human peritoneal mesothelial cells via the MAPK/P38 pathway.

    PubMed

    Yang, Lina; Wu, Lan; Du, Shuyan; Hu, Ye; Fan, Yi; Ma, Jianfei

    2016-07-01

    The regulation of cell proliferation, differentiation and immunomodulation are affected by 1,25(OH)2D3. However, its function during apoptosis and oxidative stress in human peritoneal mesothelial cells (HPMCs) remains unknown. The aim of the present study was to investigate whether the regulation of apoptosis and oxidative stress have therapeutic relevance in peritoneal dialysis (PD) therapy. The present study investigated the effects of 1,25(OH)2D3 on high glucose (HG)-induced apoptosis and reactive oxygen species (ROS) production in HPMCs, and examined the underlying molecular mechanisms. Flow cytometry and western blotting were performed to detect cell apoptosis, 2,7-dichlorofluorescein diacetate was used to measure reactive oxygen species production and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to measure cell viability. The results of the present study demonstrated that exposure to HG increased apoptosis and ROS production in HPMCs, whereas pretreatment with 1,25(OH)2D3 significantly inhibited HG‑induced apoptosis and ROS production. Further analysis revealed that 1,25(OH)2D3 facilitated cell survival via the MAPK/P38 pathway. The results of the present study indicate that 1,25(OH)2D3 inhibits apoptosis and ROS production in HG‑induced HPMCs via inhibition of the MAPK/P38 pathway. PMID:27220355

  7. MiR-31 modulates coelomocytes ROS production via targeting p105 in Vibrio splendidus challenged sea cucumber Apostichopus japonicus in vitro and in vivo.

    PubMed

    Lu, Meng; Zhang, Pengjuan; Li, Chenghua; Zhang, Weiwei; Jin, Chunhua; Han, Qingxi

    2015-08-01

    MiR-31 is a critical regulator of gene expression in many pathogenic processes in vertebrates. In this study, we identified p105 as a novel target of miR-31 in Apostichopus japonicus and investigated their regulatory roles in vitro and in vivo. The negative expression profiles between miR-31 and Ajp105 were detected in both LPS-exposed primary coelomocytes and Vibrio splendidus-challenged sea cucumber. Co-infection miR-31 mimics significantly depressed the expression of Ajp105 and increased ROS production in vitro. In contrast, miR-31 inhibitor significantly elevated the expression of Ajp105 and decreased ROS level. Consistently, miR-31 over-expression or Ajp105 silencing in vivo both greatly promoted ROS accumulation. Taken together, our findings confirmed that miR-31 could modulate respiratory burst via targeting Ajp105 during sea cucumber pathological development. PMID:25917973

  8. PPAR activation induces M1 macrophage polarization via cPLA₂-COX-2 inhibition, activating ROS production against Leishmania mexicana.

    PubMed

    Díaz-Gandarilla, J A; Osorio-Trujillo, C; Hernández-Ramírez, V I; Talamás-Rohana, P

    2013-01-01

    Defence against Leishmania depends upon Th1 inflammatory response and, a major problem in susceptible models, is the turnoff of the leishmanicidal activity of macrophages with IL-10, IL-4, and COX-2 upregulation, as well as immunosuppressive PGE2, all together inhibiting the respiratory burst. Peroxisome proliferator-activated receptors (PPAR) activation is responsible for macrophages polarization on Leishmania susceptible models where microbicide functions are deactivated. In this paper, we demonstrated that, at least for L. mexicana, PPAR activation, mainly PPAR γ , induced macrophage activation through their polarization towards M1 profile with the increase of microbicide activity against intracellular pathogen L. mexicana. PPAR activation induced IL-10 downregulation, whereas the production of proinflammatory cytokines such as TNF- α , IL-1 β , and IL-6 remained high. Moreover, PPAR agonists treatment induced the deactivation of cPLA2-COX-2-prostaglandins pathway together with an increase in TLR4 expression, all of whose criteria meet the M1 macrophage profile. Finally, parasite burden, in treated macrophages, was lower than that in infected nontreated macrophages, most probably associated with the increase of respiratory burst in these treated cells. Based on the above data, we conclude that PPAR agonists used in this work induces M1 macrophages polarization via inhibition of cPLA2 and the increase of aggressive microbicidal activity via reactive oxygen species (ROS) production. PMID:23555077

  9. Deliberate ROS production and auxin synergistically trigger the asymmetrical division generating the subsidiary cells in Zea mays stomatal complexes.

    PubMed

    Livanos, Pantelis; Galatis, Basil; Apostolakos, Panagiotis

    2016-07-01

    Subsidiary cell generation in Poaceae is an outstanding example of local intercellular stimulation. An inductive stimulus emanates from the guard cell mother cells (GMCs) towards their laterally adjacent subsidiary cell mother cells (SMCs) and triggers the asymmetrical division of the latter. Indole-3-acetic acid (IAA) immunolocalization in Zea mays protoderm confirmed that the GMCs function as local sources of auxin and revealed that auxin is polarly accumulated between GMCs and SMCs in a timely-dependent manner. Besides, staining techniques showed that reactive oxygen species (ROS) exhibit a closely similar, also time-dependent, pattern of appearance suggesting ROS implication in subsidiary cell formation. This phenomenon was further investigated by using the specific NADPH-oxidase inhibitor diphenylene iodonium, the ROS scavenger N-acetyl-cysteine, menadione which leads to ROS overproduction, and H2O2. Treatments with diphenylene iodonium, N-acetyl-cysteine, and menadione specifically blocked SMC polarization and asymmetrical division. In contrast, H2O2 promoted the establishment of SMC polarity and subsequently subsidiary cell formation in "younger" protodermal areas. Surprisingly, H2O2 favored the asymmetrical division of the intervening cells of the stomatal rows leading to the creation of extra apical subsidiary cells. Moreover, H2O2 altered IAA localization, whereas synthetic auxin analogue 1-napthaleneacetic acid enhanced ROS accumulation. Combined treatments with ROS modulators along with 1-napthaleneacetic acid or 2,3,5-triiodobenzoic acid, an auxin efflux inhibitor, confirmed the crosstalk between ROS and auxin functioning during subsidiary cell generation. Collectively, our results demonstrate that ROS are critical partners of auxin during development of Z. mays stomatal complexes. The interplay between auxin and ROS seems to be spatially and temporarily regulated. PMID:26250135

  10. Oxidative Stress Assessment in Response to Ultraendurance Exercise: Thiols Redox Status and ROS Production according to Duration of a Competitive Race

    PubMed Central

    Vezzoli, Alessandra; Dellanoce, Cinzia; Montorsi, Michela; Tonini, Annamaria; Accinni, Roberto

    2016-01-01

    Purpose. Response to an ultraendurance competitive race on thiols redox status, reactive oxygen species (ROS) production, and oxidative stress (OxS) was investigated according to duration. Methods. Twenty-four elite runners were examined: six completed 50 km and eighteen 100 km. Blood and urine samples were collected before and immediately after the race. Erythrocytes and plasma aminothiols by high-performance liquid chromatography, total antioxidant capacity (TAC), and OxS biomarkers (protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS), 8-isoprostane (8-iso-PGF2α), and 8-OH-2-deoxyguanosine (8-OH-dG)) by immunoenzymatic assays and ROS production by Electron Paramagnetic Resonance were assessed. Results. Significant increases (P between <0.05 and <0.0001) were recorded in plasma total and oxidized aminothiols concentration and TAC (P < 0.0001) only after 100 km: plasmatic (ROS production (+12 versus +29%), PC (+54 versus +115%), and TBARS (+28 versus +55%)) and urinary (8-OH-dG.creatinine−1 (+71 versus +158%) and 8-iso-PGF2α.creatinine−1 (+43 versus +135%)) concentrations for 50 and 100 km (duration 4 h 3′ versus 8 h 42′), respectively. Conclusion. Very prolonged ultraendurance exercise causes an increase in ROS production and OxS depending on specific biomarker examined but always linearly and directly related to exercise duration. Redox status of erythrocytes was preserved. A relationship between running performance and both prerace ROS production and antioxidant-redox status was found in 100 km race. PMID:27504148

  11. Chlorella Induces Stomatal Closure via NADPH Oxidase-Dependent ROS Production and Its Effects on Instantaneous Water Use Efficiency in Vicia faba

    PubMed Central

    Li, Yan; Xu, Shan-Shan; Gao, Jing; Pan, Sha; Wang, Gen-Xuan

    2014-01-01

    Reactive oxygen species (ROS) have been established to participate in stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs). Chlorella as a beneficial microorganism can be expected to trigger stomatal closure via ROS production. Here, we reported that Chlorella induced stomatal closure in a dose-and time-dependent manner in epidermal peels of Vicia faba. Using pharmacological methods in this work, we found that the Chlorella-induced stomatal closure was almost completely abolished by a hydrogen peroxide (H2O2) scavenger, catalase (CAT), significantly suppressed by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI), and slightly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM), suggesting that ROS production involved in Chlorella-induced stomatal closure is mainly mediated by DPI-sensitive NADPH oxidase. Additionally, Exogenous application of optimal concentrations of Chlorella suspension improved instantaneous water use efficiency (WUEi) in Vicia faba via a reduction in leaf transpiration rate (E) without a parallel reduction in net photosynthetic rate (Pn) assessed by gas-exchange measurements. The chlorophyll fluorescence and content analysis further demonstrated that short-term use of Chlorella did not influence plant photosynthetic reactions center. These results preliminarily reveal that Chlorella can trigger stomatal closure via NADPH oxidase-dependent ROS production in epidermal strips and improve WUEi in leave levels. PMID:24687099

  12. Hydrogen sulfide mediates hypoxic vasoconstriction through a production of mitochondrial ROS in trout gills.

    PubMed

    Skovgaard, Nini; Olson, Kenneth R

    2012-09-01

    Hypoxic pulmonary vasoconstriction (HPV) is an adaptive response that diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts. This response is important for the local matching of blood perfusion to ventilation and improves pulmonary gas exchange efficiency. HPV is an ancient and highly conserved response, expressed in the respiratory organs of all vertebrates, including lungs of mammals, birds, and reptiles; amphibian skin; and fish gills. The mechanism underlying HPV and how cells sense low Po(2) remains elusive. In perfused trout gills (Oncorhynchus mykiss), acute hypoxia, as well as H(2)S, caused an initial and transient constriction of the vasculature. Inhibition of the enzymes cystathionine-β-synthase and cystathionine-γ-lyase, which blocks H(2)S production, abolished the hypoxic response. Individually blocking the four complexes in the electron transport chain abolished both the hypoxic and the H(2)S-mediated constriction. Glutathione, an antioxidant and scavenger of superoxide, attenuated the vasoconstriction in response to hypoxia and H(2)S. Furthermore, diethyldithiocarbamate, an inhibitor of superoxide dismutase, attenuated the hypoxic and H(2)S constriction. This strongly suggests that H(2)S mediates the hypoxic vasoconstriction in trout gills. H(2)S may stimulate the mitochondrial production of superoxide, which is then converted to hydrogen peroxide (H(2)O(2)). Thus, H(2)O(2) may act as the "downstream" signaling molecule in hypoxic vasoconstriction. PMID:22739350

  13. β-Amyloid-aluminum complex alters cytoskeletal stability and increases ROS production in cortical neurons.

    PubMed

    Bolognin, Silvia; Zatta, Paolo; Lorenzetto, Erika; Valenti, Maria Teresa; Buffelli, Mario

    2013-04-01

    Several lines of evidence have supported the potential involvement of metal ions in the etiology of Alzheimer's Disease (AD). However, the molecular mechanisms underlying this interaction are still partially unknown. Previous work from our laboratory has shown that β-amyloid peptide (Aβ) aggregation was strongly influenced by the conjugation of the peptide with few metal ions (aluminum, copper, zinc, and iron) that are found in high concentrations in the senile plaque core. The binding of aluminum (Al) to Aβ specifically stabilized the peptide in an oligomeric conformation. Here, we show that the aggregation of Aβ-Al was boosted by sodium dodecyl sulfate, a detergent that mimics some characteristics of biological membrane, suggesting a potential role for membrane components in the Aβ aggregation process. Notably, we also found that Aβ-Al caused mitochondrial dysfunction and reactive oxygen species production in primary cortical neurons. Aβ-Al strongly promoted also alterations in cytoskeleton network as shown by the increased F-actin expression and the occurrence of neuritic beading. Interestingly, the neurotoxic effect of this metal complex was associated with a decreased mRNA expression of ubiquitin thiolesterase, an ubiquitin-dependent protein involved in catabolic process, and by the increased expression of glutaminyl cyclase, responsible for pathological post-translational modification of Aβ. These results suggest that, in neuronal cells, Aβ-Al can induce relevant detrimental changes that resemble pathological hallmarks of AD. PMID:23416043

  14. Atorvastatin reduces vascular endothelial growth factor (VEGF) expression in human non-small cell lung carcinomas (NSCLCs) via inhibition of reactive oxygen species (ROS) production.

    PubMed

    Chen, Jie; Liu, Bing; Yuan, Jiayi; Yang, Jie; Zhang, Jingjie; An, Yu; Tie, Lu; Pan, Yan; Li, Xuejun

    2012-02-01

    The high metastatic potential of non-small cell lung cancers (NSCLCs) is closely correlated with the elevated expression of vascular endothelial growth factor (VEGF) and resultant tumor angiogenesis. However, no effective strategies against VEGF expression have been available in NSCLCs therapy. This study demonstrated that elevated reactive oxygen species (ROS) levels derived from both mitochondria and NADPH oxidase were required for VEGF expression in NSCLC cells. Atorvastatin administration could significantly inhibit VEGF expression both in vitro and in vivo via inhibition of ROS production. Atorvastatin inhibited ROS generation partly through suppression of Rac1/NADPH oxidase activity. Specifically, atorvastatin could upregulate the activity of glutathione peroxidase (GPx) and catalase, which are responsible for elimination of hydrogen peroxide (H(2)O(2)) in the mitochondria and peroxisomes, respectively. Thus, inhibition of ROS production by concomitant suppression of Rac1/NADPH oxidase activity and upregulation of the activity of GPx and catalase contributes critically to atorvastatin-reduced VEGF expression in NSCLCs. Atorvastatin may be a potential alternative against VEGF expression and angiogenesis in NSCLCs therapy. PMID:22153388

  15. Lactate and Pyruvate Are Major Sources of Energy for Stallion Sperm with Dose Effects on Mitochondrial Function, Motility, and ROS Production.

    PubMed

    Darr, Christa R; Varner, Dickson D; Teague, Sheila; Cortopassi, Gino A; Datta, Sandipan; Meyers, Stuart A

    2016-08-01

    Stallion sperm rely primarily on oxidative phosphorylation for production of ATP used in sperm motility and metabolism. The objective of the study was to identify which substrates included in Biggers, Whitten, and Whittingham (BWW) media are key to optimal mitochondrial function through measurements of sperm motility parameters, mitochondrial oxygen consumption, and cellular reactive oxygen species (ROS) production. It was expected that mitochondrial substrates, pyruvate and lactate, would support sperm motility and mitochondrial function better than the glycolytic substrate, glucose, due to direct utilization within the mitochondria. Measurements were performed after incubation in modified BWW media with varying concentrations of lactate, pyruvate, and glucose. The effects of media and duration of incubation on sperm motility, ROS production, and oxygen consumption were determined using a linear mixed-effects model. Duplicate ejaculates from four stallions were used in three separate experiments to determine the effects of substrate availability and concentration on sperm motility and mitochondrial function and the relationship of oxygen consumption with cellular ROS production. The present results indicate that lactate and pyruvate are the most important sources of energy for stallion sperm motility and velocity, and elicit a dose-dependent response. Additionally, lactate and pyruvate are ideal for maximal mitochondrial function, as sperm in these media operate at a very high level of their bioenergetic capability due to the high rate of energy metabolism. Moreover, we found that addition of glucose to the media is not necessary for short-term storage of equine sperm, and may even result in reduction of mitochondrial function. Finally, we have confirmed that ROS production can be the result of mitochondrial dysfunction as well as intense mitochondrial activity. PMID:27335066

  16. ROS and ROS-Mediated Cellular Signaling

    PubMed Central

    Zhang, Jixiang; Wang, Xiaoli; Vikash, Vikash; Ye, Qing; Wu, Dandan; Liu, Yulan; Dong, Weiguo

    2016-01-01

    It has long been recognized that an increase of reactive oxygen species (ROS) can modify the cell-signaling proteins and have functional consequences, which successively mediate pathological processes such as atherosclerosis, diabetes, unchecked growth, neurodegeneration, inflammation, and aging. While numerous articles have demonstrated the impacts of ROS on various signaling pathways and clarify the mechanism of action of cell-signaling proteins, their influence on the level of intracellular ROS, and their complex interactions among multiple ROS associated signaling pathways, the systemic summary is necessary. In this review paper, we particularly focus on the pattern of the generation and homeostasis of intracellular ROS, the mechanisms and targets of ROS impacting on cell-signaling proteins (NF-κB, MAPKs, Keap1-Nrf2-ARE, and PI3K-Akt), ion channels and transporters (Ca2+ and mPTP), and modifying protein kinase and Ubiquitination/Proteasome System. PMID:26998193

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

    SciTech Connect

    Hu, Fen; Yang, Shuang; Zhao, Dan; Zhu, Shuyan; Wang, Yuxiang; Li, Junying

    2012-07-20

    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.

  18. ROS-induced ROS release in vascular biology: redox-redox signaling

    PubMed Central

    Zinkevich, Natalya S.

    2011-01-01

    The involvement of reactive oxygen species (ROS) in regulating vascular function both in normal vessels and as part of an adaptive response during disease has been intensively studied. From the recognition that ROS serve as important signaling molecules has emerged multiple lines of evidence that there is a functional connectivity between intracellular sites of ROS production. This cross talk has been termed ROS-induced ROS release (RIRR) and is supported by a variety of observations showing that RIRR is a common mechanism for ROS amplification and regional ROS generation. The compartmentalization of ROS production within a cell is critical to its signaling function and is facilitated by microlocalization of specific scavengers. This review will provide descriptions and examples of important mechanisms of RIRR. PMID:21685266

  19. Liver-X-receptor activator prevents homocysteine-induced production of IgG antibodies from murine B lymphocytes via the ROS-NF-{kappa}B pathway

    SciTech Connect

    Chang Lina; Zhang, Zhenmin; Li Wenjing; Dai Jing; Guan Youfei; Wang Xian . E-mail: xwang@bjmu.edu.cn

    2007-06-08

    Our previous study showed that homosysteine (Hcy) promotes proliferation of mouse splenic B lymphocytes. In this study, we investigated whether Hcy could stimulate the production of IgG antibodies. Hcy significantly increased the production of IgG antibodies from resting B lymphocytes. B lymphocytes from ApoE-knockout mice with hyperhomocysteinemia showed elevated IgG secretion at either the basal Hcy level or in response to lipopolysaccharide. Hcy promoted reactive oxygen species (ROS) formation, and free radical scavengers, MnTMPyP decreased Hcy-induced IgG secretion. The inhibitor of NF-{kappa}B (MG132) also significantly reduced Hcy-induced IgG secretion. Furthermore, Hcy-induced formation of ROS, activation of NF-{kappa}B, and secretion of IgG could be inhibited by the liver-X-receptor (LXR) agonist TO 901317. Thus, our data provide strong evidence that HHcy induces IgG production from murine splenic B lymphocytes both in vitro and in vivo. The mechanism might be through the ROS-NF-{kappa}B pathway and can be attenuated by the activation of LXR.

  20. Metabolic characterization of imatinib-resistant BCR-ABL T315I chronic myeloid leukemia cells indicates down-regulation of glycolytic pathway and low ROS production.

    PubMed

    Ko, Byung Woong; Han, Jeongsu; Heo, Jun Young; Jang, Yunseon; Kim, Soo Jeong; Kim, Jungim; Lee, Min Joung; Ryu, Min Jeong; Song, Ik Chan; Jo, Young Suk; Kweon, Gi Ryang

    2016-09-01

    Long-term imatinib treatment induces drug-resistant chronic myeloid leukemia (CML) cells harboring T315I gate keeper mutation of breakpoint cluster region (BCR)-ABL oncogenic kinase. However, although cell proliferation is coupled with cellular energy status in CML carcinogenesis, the metabolic characteristics of T315I-mutant CML cells have never been investigated. Here, we analyzed cell proliferation activities and metabolic phenotypes, including cell proliferation, oxygen consumption, lactate production, and redox state in the KBM5 (imatinib-sensitive) and KBM5-T315I (imatinib-resistant) CML cell lines. Interestingly, KBM5-T315I cells showed decreased cell proliferation, lactate production, fatty acid synthesis, ROS production, and down regulation of mRNA expression related to ROS scavengers, such as SOD2, catalase, GCLm, and GPx1. Taken together, our data demonstrate that the lower growth ability of KBM5-T315I CML cells might be related to the decreased expression of glycolysis-related genes and ROS levels, and this will be used to identify therapeutic targets for imatinib resistance in CML. PMID:26854822

  1. Revisiting Kadenbach: Electron flux rate through cytochrome c-oxidase determines the ATP-inhibitory effect and subsequent production of ROS.

    PubMed

    Vogt, Sebastian; Rhiel, Annika; Weber, Petra; Ramzan, Rabia

    2016-06-01

    Mitochondrial respiration is the predominant source of ATP. Excessive rates of electron transport cause a higher production of harmful reactive oxygen species (ROS). There are two regulatory mechanisms known. The first, according to Mitchel, is dependent on the mitochondrial membrane potential that drives ATP synthase for ATP production, and the second, the Kadenbach mechanism, is focussed on the binding of ATP to Cytochrome c Oxidase (CytOx) at high ATP/ADP ratios, which results in an allosteric conformational change to CytOx, causing inhibition. In times of stress, ATP-dependent inhibition is switched off and the activity of CytOx is exclusively determined by the membrane potential, leading to an increase in ROS production. The second mechanism for respiratory control depends on the quantity of electron transfer to the Heme aa3 of CytOx. When ATP is bound to CytOx the enzyme is inhibited, and ROS formation is decreased, although the mitochondrial membrane potential is increased. PMID:27171124

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

    PubMed Central

    Lee, Sang-Hyun; Kim, Jin-Kyoung; Jang, Hae-Dong

    2014-01-01

    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-κB ligand (RANKL)-induced RAW 264.7 cells by preventing the translocation of nuclear factor-κB (NF-κB), 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. PMID:24927148

  3. RIP kinase-mediated ROS production triggers XAF1 expression through activation of TAp73 in casticin-treated bladder cancer cells.

    PubMed

    Chung, Yoon Hee; Kim, Daejin

    2016-08-01

    The p53 family protein p73 plays an important role in apoptosis induced by chemotherapeutic drugs. Transcriptionally active (TA) p73 (TAp73) substitutes for p53 in the response to stress. XIAP associated factor 1 (XAF1) is a novel predictive and prognostic factor in patients with bladder cancer, but the association between TAp73 and XAF1 expression in bladder cancer cells is poorly understood. Here, we investigated the status of TAp73 and XAF1 in T24 bladder cancer cells to identify molecular mechanisms in casticin‑exposed T24 cells. Casticin induced activation of JNK/p38 MAPK that preceded activation of the caspase cascade and disruption of the mitochondria membrane potential (∆ψm). Expression of XAF1 and TAp73 was also upregulated in casticin-treated T24 cells. Casticin treatment of T24 cells induced receptor-interacting protein (RIP) kinase expression and increased intracellular production of reactive oxygen species (ROS). Casticin-mediated ROS induced an increase in phosphorylated JNK/p38 MAPK, resulting in progressive upregulation of TAp73, which in turn led to XAF1 expression. Our data suggest that the apoptotic activity of casticin in T24 cells is mediated by activation of the TAp73-XAF1 signaling pathway through RIP kinase-mediated ROS production. PMID:27349281

  4. Effects of TiO2 nanoparticles on ROS production and growth inhibition using freshwater green algae pre-exposed to UV irradiation.

    PubMed

    Fu, Ling; Hamzeh, Mahsa; Dodard, Sabine; Zhao, Yuan H; Sunahara, Geoffrey I

    2015-05-01

    This study investigated the possibility that titanium dioxide nanoparticles (nano-TiO2) toxicity in Pseudokirchneriella subcapitata involves reactive oxygen species (ROS) production, using the dichlorodihydrofluorescein (DCF) assay. Algae were exposed to nano-TiO2 under laboratory fluorescent lamps supplemented with UV irradiation for 3h, with or without a UV filter. Results showed that nano-TiO2 increased ROS production in UV-exposed cells, with or without a UV filter (LOEC values were 250 and 10mg/L, respectively). Sublethal effects of nano-TiO2 on UV pre-exposed algae were also examined. Toxicity studies indicated that exposure to nano-TiO2 agglomerates decreased algal growth following 3h pre-exposure to UV, with or without a UV filter (EC50s were 8.7 and 6.3mg/L, respectively). The present study suggests that the growth inhibitory effects of nano-TiO2 in algae occurred at concentrations lower than those that can elevate DCF fluorescence, and that ROS generation is not directly involved with the sublethal effects of nano-TiO2 in algae. PMID:25867689

  5. ROS production and gene expression in alveolar macrophages exposed to PM(2.5) from Baghdad, Iraq: Seasonal trends and impact of chemical composition.

    PubMed

    Hamad, Samera H; Schauer, James J; Antkiewicz, Dagmara S; Shafer, Martin M; Kadhim, Ahmed Kh

    2016-02-01

    The objective of this study was to assess the impact of changes in atmospheric particulate matter (PM) composition on oxidative stress markers in an in-vitro alveolar macrophage (AM) model. Fifty-three PM2.5 samples were collected during a year-long PM sampling campaign in Baghdad, Iraq, a semi-arid region of the country. Monthly composites were analyzed for chemical composition and for biological activity using in-vitro measurements of ROS production and gene expression in the AM model. Twelve genes that were differentially expressed upon PM exposure were identified and their co-associations with the composition of PM2.5 were examined. Ten of those genes were up-regulated in January and April composites; samples which also exhibited high ROS activity and relatively high PM mass concentration. ROS production was statistically correlated with total PM2.5 mass, levoglucosan (a wood burning tracer) and several trace elements of the PM (especially V and Ni, which are associated with oil combustion). The expression of several cytokine genes was found to be moderately associated with PM mass, crustal materials (indication of dusty days or dust storms) and certain metals (e.g. V, Fe and Ni) in the PM. Thus, the ROS activity association with PM2.5, may, in part, be driven by redox-active metals. The antioxidant response genes (Nqo1 and Hmox1) were moderately associated with polyaromatic hydrocarbons (PAHs) and showed a good correlation (r-Pearson of >0.7) with metals linked to vehicle-related emissions (i.e. Cu, Zn and Sb). Examining these associations in a larger sample pool (e.g. daily samples) would improve the power of the analysis and may strengthen the implication of these chemicals in the oxidative stress of biological systems, which could aid in the development of new metrics of PM toxicity. PMID:26618301

  6. Relationship of semen hyperviscosity with IL-6, TNF-α, IL-10 and ROS production in seminal plasma of infertile patients with prostatitis and prostato-vesiculitis.

    PubMed

    Castiglione, R; Salemi, M; Vicari, L O; Vicari, E

    2014-12-01

    Changes in levels of oxidative damage products in semen and their relationship to seminal fluid viscosity (SFV) have recently received increasing research interest. We analysed whether SFV was associated with ROS generation, levels of cytokines TNF-alpha (TNF-α), IL-6 and IL-10 and seminal leucocyte concentration, and whether ROS production was related to the extent of infections/inflammations at one (prostatitis) or two (prostato-vesiculitis) male accessory glands. We studied 169 infertile patients, with chronic bacterial prostatitis (PR, n = 74) and/or bilateral prostato-vesiculitis (PV, n = 95), as diagnosed by the ultrasound (US) criteria. Healthy fertile men (n = 42) served as controls. In the PV patient group, SFV, semen characteristics and ROS production had median values that were significantly higher than those found in PR patients and controls, although other sperm variables had values significantly lower than those found in PR patients or controls. In PV infertile patients, ROS generation and pro-inflammatory cytokines levels were higher than those found in PR infertile patients and controls, although seminal IL-10 levels in PV and PR patients were lower than those found in the controls. In PR patients, the levels of SFV were positively related to TNF-α (r = 0.67; P < 0.01), fMLP-stimulated ROS production in the 45% Percoll fraction (r = 0.687, P < 0.01) and the 90% Percoll fraction in basal condition (r = 0.695, P < 0.01), and after fMLP-stimulation (r = 0.688, P < 0.01). Thus, our data indicated that seminal hyperviscosity is associated with increased oxidative stress in infertile men and increased pro-inflammatory interleukins in patients with male accessory gland infection, more when the infection was extended to the seminal vesicles. PMID:24329571

  7. Effective Inhibition of Cellular ROS Production by MXCXXC-Type Peptides: Potential Therapeutic Applications in Copper-Homeostasis Disorders.

    PubMed

    Shoshan, Michal S; Tshuva, Edit Y

    2016-06-27

    Cyclic and acyclic peptides with sequences derived from metallochaperone binding sites, but differing at position 2, were analyzed for their inhibitory reactivity towards cellular ROS (reactive oxygen species) formation and catalytic activity towards oxidation with H2 O2 , in comparison with three commercial drugs clinically employed in chelation therapy for Wilson's disease. Acyclic peptides were more effective inhibitors than the cyclic ones, with one leading peptide with threonine at position 2 systematically showing the highest efficiency in reducing cellular ROS levels and in inhibiting Cu oxidation. This peptide was more effective than all commercial drugs in all aspects analyzed, and showed no toxicity towards human colon HT-29 cancer cells at concentrations 10-100 times higher than the IC50 of the commercial drugs, corroborating its high medicinal potential. PMID:27124086

  8. The chlorinated AHR ligand 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) promotes reactive oxygen species (ROS) production during embryonic development in the killifish (Fundulus heteroclitus)

    USGS Publications Warehouse

    Arzuaga, Xabier; Wassenberg, Deena; Giulio, Richard D.; Elskus, Adria

    2006-01-01

    Exposure to dioxin-like chemicals that activate the aryl hydrocarbon receptor (AHR) can result in increased cellular and tissue production of reactive oxygen species (ROS). Little is known of these effects during early fish development. We used the fish model, Fundulus heteroclitus, to determine if the AHR ligand and pro-oxidant 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) can increase ROS production during killifish development, and to test a novel method for measuring ROS non-invasively in a living organism. The superoxide-sensitive fluorescent dye, dihydroethidium (DHE), was used to detect in ovo ROS production microscopically in developing killifish exposed to PCB126 or vehicle. Both in ovo CYP1A activity (ethoxyresorufin-o-deethylase, EROD) and in ovo ROS were induced by PCB126. In ovo CYP1A activity was inducible by PCB126 concentrations as low as 0.003 nM, with maximal induction occurring at 0.3 nM PCB126. These PCB126 concentrations also significantly increased in ovo ROS production in embryonic liver, ROS being detectable as early as 5 days post-fertilization. These data demonstrate that the pro-oxidant and CYP1A inducer, PCB126, increases both CYP1A activity and ROS production in developing killifish embryos. The superoxide detection assay (SoDA) described in this paper provides a semi-quantitative, easily measured, early indicator of altered ROS production that can be used in conjunction with simultaneous in ovo measurements of CYP1A activity and embryo development to explore functional relationships among biochemical, physiological and developmental responses to AHR ligands.

  9. Effect of selenite on T-cell mitogenesis: contribution of ROS production and apoptosis signal-regulating kinase 1.

    PubMed

    Ueno, Hitoshi; Kajihara, Hitomi; Nakamura, Hajime; Okuno, Tomofumi; Sakazaki, Fumitoshi; Arakawa, Tomohiro; Ogino, Hirofumi; Nakamuro, Katsuhiko; Yodoi, Junji

    2014-01-01

    Although supplementation with the selenocompound, sodium selenite has been shown to stimulate the concanavalin A-induced T-cell mitogenic response, the mechanisms responsible remain unclear. This study was conducted to evaluate the relationships between the induction of apoptosis, formation of tumor necrosis factor (TNF)-alpha and reactive oxygen species (ROS), activation of apoptosis signal-regulating kinase (ASK) 1 and the thioredoxin (Trx) system when mitogenesis was stimulated by selenite. TNF-alpha was dose-dependently released by mouse splenocytes treated with selenite, and apoptosis was induced when TNF-alpha was added at the indicated concentrations. However, supplementation with selenite at low concentrations inhibited the accumulation of ROS with the increased expression of Trx reductase 1 and induction of apoptosis in wild-type splenocytes, and also at high concentrations in Trx-1-transgenic mouse splenocytes. The suppression of apoptosis was accompanied by a decrease in the expression of phospho-ASK1. These results suggest that the stimulation of T-cell mitogenesis by selenite may be partly attributed to the inhibited accumulation of ROS due to a reduced Trx-1/TR1 system, the inactivation of ASK1, and the suppression of apoptosis. PMID:25087957

  10. Activation of MAPK Is Required for ROS Generation and Exocytosis in HMC-1 Cells Induced by Trichomonas vaginalis-Derived Secretory Products

    PubMed Central

    Narantsogt, Giimaa; Min, Arim; Nam, Young Hee; Lee, Young Ah; Kim, Kyeong Ah; Agvaandaram, Gurbadam; Dorjsuren, Temuulen; El-Benna, Jamel; Shin, Myeong Heon

    2015-01-01

    Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen-activated protein kinase (MAPK), activated by various stimuli, have been shown to regulate the transcriptional activity of various cytokine genes in mast cells. In this study, we investigated whether MAPK is involved in ROS generation and exocytotic degranulation in HMC-1 cells induced by T. vaginalis-derived secretory products (TvSP). We found that TvSP induces the activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and p47phox in HMC-1 cells. Stimulation with TvSP also induced up-regulation of CD63, a marker for exocytosis, along the surfaces of human mast cells. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation. Finally, our results suggest that TvSP induces intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling. PMID:26537039

  11. Exogenous C2 Ceramide Suppresses Matrix Metalloproteinase Gene Expression by Inhibiting ROS Production and MAPK Signaling Pathways in PMA-Stimulated Human Astroglioma Cells.

    PubMed

    Jung, Ji-Sun; Ahn, Young-Ho; Moon, Byung-In; Kim, Hee-Sun

    2016-01-01

    Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases, which play a pivotal role in invasion, migration, and angiogenesis of glioma. Therefore, controlling MMPs is potentially an important therapeutic strategy for glioma. In the present study, we found that exogenous cell-permeable short-chain C2 ceramide inhibits phorbol myristate acetate (PMA)-induced MMP-1, -3, and -9 gene expressions in U87MG and U373MG human astroglioma cells. In addition, C2 ceramide inhibited the protein secretion and enzymatic activities of MMP-1, -3, and -9. The Matrigel invasion assay and wound healing assay showed that C2 ceramide suppresses the in vitro invasion and migration of glioma cells, which appears to be involved in strong inhibition of MMPs by C2 ceramide. Subsequent mechanistic studies revealed that C2 ceramide inhibits PMA-induced mitogen-activated protein kinase (MAPK) phosphorylation and nuclear factor (NF)-κB/activator protein (AP)-1 DNA binding activities. Furthermore, C2 ceramide significantly inhibited PMA-induced reactive oxygen species (ROS) production and NADPH oxidase 4 (NOX4) expression, and inhibition of ROS by diphenylene iodonium (DPI, NADPH oxidase inhibitor) mimicked the effects of C2 ceramide on MMP expression and NF-κB/AP-1 via inhibition of p38 MAPK. The results suggest C2 ceramide inhibits MMP expression and glioma invasion, at least partly, by modulating ROS-p38 MAPK signaling axis and other MAPK signaling pathways. PMID:27043542

  12. Cellular responses associated with ROS production and cell fate decision in early stress response to iron limitation in the diatom Thalassiosira pseudonana.

    PubMed

    Luo, Chun-Shan; Liang, Jun-Rong; Lin, Qun; Li, Caixia; Bowler, Chris; Anderson, Donald M; Wang, Peng; Wang, Xin-Wei; Gao, Ya-Hui

    2014-12-01

    Investigation of how diatoms cope with the rapid fluctuations in iron bioavailability in marine environments may facilitate a better understanding of the mechanisms underlying their ecological success, in particular their ability to proliferate rapidly during favorable conditions. In this study, using in vivo biochemical markers and whole-cell iTRAQ-based proteomics analysis, we explored the cellular responses associated with reactive oxygen species (ROS) production and cell fate decision during the early response to Fe limitation in the centric diatom Thalassiosira pseudonana. Fe limitation caused a significant decrease in Photosystem (PS) II photosynthetic efficiency, damage to the photosynthetic electron transport chain in PS I, and blockage of the respiratory chain in complexes III and IV, which could all result in excess ROS accumulation. The increase in ROS likely triggered programmed cell death (PCD) in some of the Fe-limited cells through synthesis of a series of proteins involved in the delicate balance between pro-survival and pro-PCD factors. The results provide molecular-level insights into the major strategies that may be employed by T. pseudonana in response to Fe-limitation: the reduction of cell population density through PCD to reduce competition for available Fe, the reallocation of intracellular nitrogen and Fe to ensure survival, and an increase in expression of antioxidant and anti-PCD proteins to cope with stress. PMID:25372880

  13. Cellular Responses Associated with ROS Production and Cell Fate Decision in Early Stress Response to Iron Limitation in the Diatom Thalassiosira pseudonana

    PubMed Central

    2015-01-01

    Investigation of how diatoms cope with the rapid fluctuations in iron bioavailability in marine environments may facilitate a better understanding of the mechanisms underlying their ecological success, in particular their ability to proliferate rapidly during favorable conditions. In this study, using in vivo biochemical markers and whole-cell iTRAQ-based proteomics analysis, we explored the cellular responses associated with reactive oxygen species (ROS) production and cell fate decision during the early response to Fe limitation in the centric diatom Thalassiosira pseudonana. Fe limitation caused a significant decrease in Photosystem (PS) II photosynthetic efficiency, damage to the photosynthetic electron transport chain in PS I, and blockage of the respiratory chain in complexes III and IV, which could all result in excess ROS accumulation. The increase in ROS likely triggered programmed cell death (PCD) in some of the Fe-limited cells through synthesis of a series of proteins involved in the delicate balance between pro-survival and pro-PCD factors. The results provide molecular-level insights into the major strategies that may be employed by T. pseudonana in response to Fe-limitation: the reduction of cell population density through PCD to reduce competition for available Fe, the reallocation of intracellular nitrogen and Fe to ensure survival, and an increase in expression of antioxidant and anti-PCD proteins to cope with stress. PMID:25372880

  14. Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation

    PubMed Central

    Cheng, Yuanyuan; Xia, Zhengyuan; Han, Yifan; Rong, Jianhui

    2016-01-01

    The opening of mitochondrial permeability transition pore (mPTP) is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD) and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS) and glycogen synthase kinase 3β (GSK-3β), in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9) phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT) while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9) was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation. PMID:27034732

  15. Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation.

    PubMed

    Cheng, Yuanyuan; Xia, Zhengyuan; Han, Yifan; Rong, Jianhui

    2016-01-01

    The opening of mitochondrial permeability transition pore (mPTP) is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD) and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS) and glycogen synthase kinase 3β (GSK-3β), in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9) phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT) while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9) was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation. PMID:27034732

  16. Exogenous C2 Ceramide Suppresses Matrix Metalloproteinase Gene Expression by Inhibiting ROS Production and MAPK Signaling Pathways in PMA-Stimulated Human Astroglioma Cells

    PubMed Central

    Jung, Ji-Sun; Ahn, Young-Ho; Moon, Byung-In; Kim, Hee-Sun

    2016-01-01

    Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases, which play a pivotal role in invasion, migration, and angiogenesis of glioma. Therefore, controlling MMPs is potentially an important therapeutic strategy for glioma. In the present study, we found that exogenous cell-permeable short-chain C2 ceramide inhibits phorbol myristate acetate (PMA)-induced MMP-1, -3, and -9 gene expressions in U87MG and U373MG human astroglioma cells. In addition, C2 ceramide inhibited the protein secretion and enzymatic activities of MMP-1, -3, and -9. The Matrigel invasion assay and wound healing assay showed that C2 ceramide suppresses the in vitro invasion and migration of glioma cells, which appears to be involved in strong inhibition of MMPs by C2 ceramide. Subsequent mechanistic studies revealed that C2 ceramide inhibits PMA-induced mitogen-activated protein kinase (MAPK) phosphorylation and nuclear factor (NF)-κB/activator protein (AP)-1 DNA binding activities. Furthermore, C2 ceramide significantly inhibited PMA-induced reactive oxygen species (ROS) production and NADPH oxidase 4 (NOX4) expression, and inhibition of ROS by diphenylene iodonium (DPI, NADPH oxidase inhibitor) mimicked the effects of C2 ceramide on MMP expression and NF-κB/AP-1 via inhibition of p38 MAPK. The results suggest C2 ceramide inhibits MMP expression and glioma invasion, at least partly, by modulating ROS-p38 MAPK signaling axis and other MAPK signaling pathways. PMID:27043542

  17. Helicobacter pylori induces IL-1β and IL-18 production in human monocytic cell line through activation of NLRP3 inflammasome via ROS signaling pathway.

    PubMed

    Li, Xiang; Liu, Sheng; Luo, Jingjing; Liu, Anyuan; Tang, Shuangyang; Liu, Shuo; Yu, Minjun; Zhang, Yan

    2015-06-01

    This study investigated whether Helicobacter pylori could activate the nucleotide-binding oligomerization domain-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome in human macrophages and the involvement of reactive oxygen species (ROS) in inflammasome activation. Phorbol-12-myristate-13-acetate (PMA)-differentiated human acute monocytic leukemia cell line THP-1 was infected with H. pylori. The levels of pro-inflammatory cytokines interleukin (IL)-1β and IL-18 in supernatant were measured by ELISA. Intracellular ROS level was analyzed by flow cytometry. Quantitative real-time PCR and western blot analysis were employed to determine the mRNA and protein expression levels of NLRP3 and caspase-1 in THP-1 cells, respectively. Our results showed that H. pylori infection could induce IL-1β and IL-18 production in PMA-differentiated THP-1 cells in a dose- and time-dependent manner. Moreover, secretion of IL-1β and IL-18 in THP-1 cells following H. pylori infection was remarkably reduced by NLRP3-specific small interfering RNA treatment. In addition, the intracellular ROS level was elevated by H. pylori infection, which could be eliminated by the ROS scavenger N-acetylcysteine (NAC). Furthermore, NAC treatment could inhibit NLRP3 inflammasome formation and caspase-1 activation and suppress the release of IL-1β and IL-18 from H. pylori-infected THP-1 cells. These findings provide novel insights into the innate immune response against H. pylori infection, which could potentially be used for the prevention and treatment of H. pylori-related diseases. PMID:25834143

  18. Altered ROS production, NF-κB activation and Interleukin-6 gene expression induced by electrical stimulation of in dystrophic mdx skeletal muscle cells

    PubMed Central

    Henríquez-Olguín, Carlos; Altamirano, Francisco; Valladares, Denisse; López, José R.; Allen, Paul D.; Jaimovich, Enrique

    2015-01-01

    Duchenne Muscular Dystrophy (DMD) is a fatal X-linked genetic disease, caused by mutations in the dystrophin gene, which cause functional loss of this protein. DMD pathology is associated with an increased production of reactive oxygen and nitrogen species (ROS and RNS). The aim of this work was to study the alterations in NF-κB activation and Interleukin-6 (IL-6) expression induced by membrane depolarization in dystrophic mdx myotubes. Membrane depolarization elicited by electrical stimulation (ES) increased p65 phosphorylation, NF-κB transcriptional activity and NF-κB-dependent IL-6 expression in wt myotubes, whereas in mdx myotubes it had the opposite effect. We have previously shown that depolarization-induced intracellular Ca2+ increases and ROS production are necessary for NF-κB activation and stimulation of gene expression in wt myotubes. Dystrophic myotubes showed a reduced amplitude and area under the curve of the Ca2+ transient elicited by ES. On the other hand, ES induced higher ROS production in mdx than wt myotubes, which were blocked by NOX2 inhibitors. Moreover, mRNA expression and protein levels of the NADPH oxidase subunits; p47phox and gp91phox were increased in mdx myotubes. Looking at ROS-dependence of NF-κB activation we found that in wt myotubes external administration of 50µM H2O2 increased NF-κB activity; after administration of 100 and 200 µM H2O2 there was no effect. In mdx myotubes there was a dose-dependent reduction in NF-κB activity in response to external administration of H2O2, with a significant effect of 100 µM and 200 µM, suggesting that ROS levels are critical for NF-κB activity. Prior blockage with NOX2 inhibitors blunted the effects of ES in both NF-κB activation and IL-6 expression. Finally, to ascertain whether stimulation of NF-κB and IL-6 gene expression by the inflammatory pathway is also impaired in mdx myotubes, we studied the effect of lipopolysaccharide (LPS) on both NF-κB activation and IL-6 expression

  19. Altered ROS production, NF-κB activation and interleukin-6 gene expression induced by electrical stimulation in dystrophic mdx skeletal muscle cells.

    PubMed

    Henríquez-Olguín, Carlos; Altamirano, Francisco; Valladares, Denisse; López, José R; Allen, Paul D; Jaimovich, Enrique

    2015-07-01

    Duchenne muscular dystrophy is a fatal X-linked genetic disease, caused by mutations in the dystrophin gene, which cause functional loss of this protein. This pathology is associated with an increased production of reactive oxygen (ROS) and nitrogen species. The aim of this work was to study the alterations in NF-κB activation and interleukin-6 (IL-6) expression induced by membrane depolarization in dystrophic mdx myotubes. Membrane depolarization elicited by electrical stimulation increased p65 phosphorylation, NF-κB transcriptional activity and NF-κB-dependent IL-6 expression in wt myotubes, whereas in mdx myotubes it had the opposite effect. We have previously shown that depolarization-induced intracellular Ca2+ increases and ROS production are necessary for NF-κB activation and stimulation of gene expression in wt myotubes. Dystrophic myotubes showed a reduced amplitude and area under the curve of the Ca2+ transient elicited by electrical stimulation. On the other hand, electrical stimuli induced higher ROS production in mdx than wt myotubes, which were blocked by NOX2 inhibitors. Moreover, mRNA expression and protein levels of the NADPH oxidase subunits: p47phox and gp91phox were increased in mdx myotubes. Looking at ROS-dependence of NF-κB activation we found that in wt myotubes external administration of 50 μM H2O2 increased NF-κB activity; after administration of 100 and 200 μM H2O2 there was no effect. In mdx myotubes there was a dose-dependent reduction in NF-κB activity in response to external administration of H2O2, with a significant effect of 100 μM and 200 μM, suggesting that ROS levels are critical for NF-κB activity. Prior blockage with NOX2 inhibitors blunted the effects of electrical stimuli in both NF-κB activation and IL-6 expression. Finally, to ascertain whether stimulation of NF-κB and IL-6 gene expression by the inflammatory pathway is also impaired in mdx myotubes, we studied the effect of lipopolysaccharide on both NF

  20. Mitochondrial Respiratory Chain Inhibitors Involved in ROS Production Induced by Acute High Concentrations of Iodide and the Effects of SOD as a Protective Factor

    PubMed Central

    Wang, Lingyan; Duan, Qi; Wang, Tingting; Ahmed, Mohamed; Zhang, Na; Li, Yongmei; Li, Lanying; Yao, Xiaomei

    2015-01-01

    A major source of reactive oxygen species (ROS) generation is the mitochondria. By using flow cytometry of the mitochondrial fluorescent probe, MitoSOX Red, western blot of mitochondrial ROS scavenger Peroxiredoxin (Prx) 3 and fluorescence immunostaining, ELISA of cleaved caspases 3 and 9, and TUNEL staining, we demonstrated that exposure to 100 μM KI for 2 hours significantly increased mitochondrial superoxide production and Prx 3 protein expression with increased expressions of cleaved caspases 3 and 9. Besides, we indicated that superoxide dismutase (SOD) at 1000 unit/mL attenuated the increase in mitochondrial superoxide production, Prx 3 protein expression, and lactate dehydrogenase (LDH) release and improved the relative cell viability at 100 μM KI exposure. However, SOD inhibitor diethyldithiocarbamic acid (DETC) (2 mM), Rotenone (0.5 μM), a mitochondrial complex I inhibitor, and Antimycin A (10 μM), a complex III inhibitor, caused an increase in mitochondrial superoxide production, Prx 3 protein expression, and LDH release and decreased the relative cell viability. We conclude that the inhibitors of mitochondrial respiratory chain complex I or III may be involved in oxidative stress caused by elevated concentrations of iodide, and SOD demonstrates its protective effect on the Fischer rat thyroid cell line (FRTL) cells. PMID:26294939

  1. ROS Regulation During Abiotic Stress Responses in Crop Plants

    PubMed Central

    You, Jun; Chan, Zhulong

    2015-01-01

    Abiotic stresses such as drought, cold, salt and heat cause reduction of plant growth and loss of crop yield worldwide. Reactive oxygen species (ROS) including hydrogen peroxide (H2O2), superoxide anions (O2•-), hydroxyl radical (OH•) and singlet oxygen (1O2) are by-products of physiological metabolisms, and are precisely controlled by enzymatic and non-enzymatic antioxidant defense systems. ROS are significantly accumulated under abiotic stress conditions, which cause oxidative damage and eventually resulting in cell death. Recently, ROS have been also recognized as key players in the complex signaling network of plants stress responses. The involvement of ROS in signal transduction implies that there must be coordinated function of regulation networks to maintain ROS at non-toxic levels in a delicate balancing act between ROS production, involving ROS generating enzymes and the unavoidable production of ROS during basic cellular metabolism, and ROS-scavenging pathways. Increasing evidence showed that ROS play crucial roles in abiotic stress responses of crop plants for the activation of stress-response and defense pathways. More importantly, manipulating ROS levels provides an opportunity to enhance stress tolerances of crop plants under a variety of unfavorable environmental conditions. This review presents an overview of current knowledge about homeostasis regulation of ROS in crop plants. In particular, we summarize the essential proteins that are involved in abiotic stress tolerance of crop plants through ROS regulation. Finally, the challenges toward the improvement of abiotic stress tolerance through ROS regulation in crops are discussed. PMID:26697045

  2. Modulation of Potassium Channel Activity in the Balance of ROS and ATP Production by Durum Wheat Mitochondria-An Amazing Defense Tool Against Hyperosmotic Stress.

    PubMed

    Trono, Daniela; Laus, Maura N; Soccio, Mario; Alfarano, Michela; Pastore, Donato

    2015-01-01

    In plants, the existence of a mitochondrial potassium channel was firstly demonstrated about 15 years ago in durum wheat as an ATP-dependent potassium channel (PmitoKATP). Since then, both properties of the original PmitoKATP and occurrence of different mitochondrial potassium channels in a number of plant species (monocotyledonous and dicotyledonous) and tissues/organs (etiolated and green) have been shown. Here, an overview of the current knowledge is reported; in particular, the issue of PmitoKATP physiological modulation is addressed. Similarities and differences with other potassium channels, as well as possible cross-regulation with other mitochondrial proteins (Plant Uncoupling Protein, Alternative Oxidase, Plant Inner Membrane Anion Channel) are also described. PmitoKATP is inhibited by ATP and activated by superoxide anion, as well as by free fatty acids (FFAs) and acyl-CoAs. Interestingly, channel activation increases electrophoretic potassium uptake across the inner membrane toward the matrix, so collapsing membrane potential (ΔΨ), the main component of the protonmotive force (Δp) in plant mitochondria; moreover, cooperation between PmitoKATP and the K(+)/H(+) antiporter allows a potassium cycle able to dissipate also ΔpH. Interestingly, ΔΨ collapse matches with an active control of mitochondrial reactive oxygen species (ROS) production. Fully open channel is able to lower superoxide anion up to 35-fold compared to a condition of ATP-inhibited channel. On the other hand, ΔΨ collapse by PmitoKATP was unexpectedly found to not affect ATP synthesis via oxidative phosphorylation. This may probably occur by means of a controlled collapse due to ATP inhibition of PmitoKATP; this brake to the channel activity may allow a loss of the bulk phase Δp, but may preserve a non-classically detectable localized driving force for ATP synthesis. This ability may become crucial under environmental/oxidative stress. In particular, under moderate hyperosmotic stress

  3. Modulation of Potassium Channel Activity in the Balance of ROS and ATP Production by Durum Wheat Mitochondria—An Amazing Defense Tool Against Hyperosmotic Stress

    PubMed Central

    Trono, Daniela; Laus, Maura N.; Soccio, Mario; Alfarano, Michela; Pastore, Donato

    2015-01-01

    In plants, the existence of a mitochondrial potassium channel was firstly demonstrated about 15 years ago in durum wheat as an ATP-dependent potassium channel (PmitoKATP). Since then, both properties of the original PmitoKATP and occurrence of different mitochondrial potassium channels in a number of plant species (monocotyledonous and dicotyledonous) and tissues/organs (etiolated and green) have been shown. Here, an overview of the current knowledge is reported; in particular, the issue of PmitoKATP physiological modulation is addressed. Similarities and differences with other potassium channels, as well as possible cross-regulation with other mitochondrial proteins (Plant Uncoupling Protein, Alternative Oxidase, Plant Inner Membrane Anion Channel) are also described. PmitoKATP is inhibited by ATP and activated by superoxide anion, as well as by free fatty acids (FFAs) and acyl-CoAs. Interestingly, channel activation increases electrophoretic potassium uptake across the inner membrane toward the matrix, so collapsing membrane potential (ΔΨ), the main component of the protonmotive force (Δp) in plant mitochondria; moreover, cooperation between PmitoKATP and the K+/H+ antiporter allows a potassium cycle able to dissipate also ΔpH. Interestingly, ΔΨ collapse matches with an active control of mitochondrial reactive oxygen species (ROS) production. Fully open channel is able to lower superoxide anion up to 35-fold compared to a condition of ATP-inhibited channel. On the other hand, ΔΨ collapse by PmitoKATP was unexpectedly found to not affect ATP synthesis via oxidative phosphorylation. This may probably occur by means of a controlled collapse due to ATP inhibition of PmitoKATP; this brake to the channel activity may allow a loss of the bulk phase Δp, but may preserve a non-classically detectable localized driving force for ATP synthesis. This ability may become crucial under environmental/oxidative stress. In particular, under moderate hyperosmotic stress

  4. Human cell line-dependent WC-Co nanoparticle cytotoxicity and genotoxicity: a key role of ROS production.

    PubMed

    Paget, V; Moche, H; Kortulewski, T; Grall, R; Irbah, L; Nesslany, F; Chevillard, S

    2015-02-01

    Although tungsten carbide-cobalt (WC-Co) nanoparticles (NPs) have been widely used because of their robustness, their risk to human health remains poorly studied, despite the International Agency for Research on Cancer (IARC) classifying them as "probably carcinogenic" for humans (Group 2A) in 2006. Our current study aimed at defining the cytotoxicity and genotoxicity of one set of commercially available 60-nm diameter WC-Co NPs on three human cell lines representative of potential target organs: A549 (lung), Hep3B (liver), and Caki-1 (kidney). The cytotoxicity of WC-Co NPs was determined by evaluating cell impedance (xCELLigence), cell survival/death, and cell cycle checkpoints. Flow cytometry was used to not only evaluate cell cycle checkpoints, but to also estimate reactive oxygen species (ROS) generation. In addition, γ-H2Ax foci detection (confocal microscopy), considered to be the most sensitive technique for studying DNA double-strand breaks, was utilized to evaluate genotoxicity. As a final part of this study, we assessed the cellular incorporation of WC-Co NPs, first byflow cytometry (side scatter), and then by confocal microscopy (light reflection) to ensure that the NPs had entered cells. Overall, our current findings demonstrate that WC-Co NPs induce cell mortality, DNA double-strand breaks, and cell cycle arrest in human renal (Caki-1) and liver (Hep3B) cell lines, but do not induce significant cytotoxic effects in A549 lung cells. Interestingly, although WC-Co NPs effectively entered the cells in all 3 lines tested, ROS were detected in Caki-1 and Hep3B, but not in A549. This may explain the great differences in the cytotoxic and genotoxic effects we observed between these lines. PMID:25398624

  5. Effects of 5-Fluorouracil on Morphology, Cell Cycle, Proliferation, Apoptosis, Autophagy and ROS Production in Endothelial Cells and Cardiomyocytes

    PubMed Central

    Focaccetti, Chiara; Bruno, Antonino; Magnani, Elena; Bartolini, Desirée; Principi, Elisa; Dallaglio, Katiuscia; Bucci, Eraldo O.; Finzi, Giovanna; Sessa, Fausto; Noonan, Douglas M.; Albini, Adriana

    2015-01-01

    Antimetabolites are a class of effective anticancer drugs interfering in essential biochemical processes. 5-Fluorouracil (5-FU) and its prodrug Capecitabine are widely used in the treatment of several solid tumors (gastro-intestinal, gynecological, head and neck, breast carcinomas). Therapy with fluoropyrimidines is associated with a wide range of adverse effects, including diarrhea, dehydration, abdominal pain, nausea, stomatitis, and hand-foot syndrome. Among the 5-FU side effects, increasing attention is given to cardiovascular toxicities induced at different levels and intensities. Since the mechanisms related to 5-FU-induced cardiotoxicity are still unclear, we examined the effects of 5-FU on primary cell cultures of human cardiomyocytes and endothelial cells, which represent two key components of the cardiovascular system. We analyzed at the cellular and molecular level 5-FU effects on cell proliferation, cell cycle, survival and induction of apoptosis, in an experimental cardioncology approach. We observed autophagic features at the ultrastructural and molecular levels, in particular in 5-FU exposed cardiomyocytes. Reactive oxygen species (ROS) elevation characterized the endothelial response. These responses were prevented by a ROS scavenger. We found induction of a senescent phenotype on both cell types treated with 5-FU. In vivo, in a xenograft model of colon cancer, we showed that 5-FU treatment induced ultrastructural changes in the endothelium of various organs. Taken together, our data suggest that 5-FU can affect, both at the cellular and molecular levels, two key cell types of the cardiovascular system, potentially explaining some manifestations of 5-FU-induced cardiovascular toxicity. PMID:25671635

  6. Actin depolymerization mediated loss of SNTA1 phosphorylation and Rac1 activity has implications on ROS production, cell migration and apoptosis.

    PubMed

    Bhat, Sehar Saleem; Parray, Arif Ali; Mushtaq, Umar; Fazili, Khalid Majid; Khanday, Firdous Ahmad

    2016-06-01

    Alpha-1-syntrophin (SNTA1) and Rac1 are part of a signaling pathway via the dystrophin glycoprotein complex (DGC). Both SNTA1 and Rac1 proteins are over-expressed in various carcinomas. It is through the DGC signaling pathway that SNTA1 has been shown to act as a link between the extra cellular matrix, the internal cell signaling apparatus and the actin cytoskeleton. SNTA1 is involved in the modulation of the actin cytoskeleton and actin reorganization. Rac1 also controls actin cytoskeletal organization in the cell. In this study, we present the interplay between f-actin, SNTA1 and Rac1. We analyzed the effect of actin depolymerization on SNTA1 tyrosine phosphorylation and Rac1 activity using actin depolymerizing drugs, cytochalasin D and latrunculin A. Our results indicate a marked decrease in the tyrosine phosphorylation of SNTA1 upon actin depolymerization. Results suggest that actin depolymerization mediated loss of SNTA1 phosphorylation leads to loss of interaction between SNTA1 and Rac1, with a concomitant loss of Rac1 activation. The loss of SNTA1tyrosine phosphorylation and Rac1 activity by actin depolymerization results in increased apoptosis, decreased cell migration and decreased reactive oxygen species (ROS) levels in breast carcinoma cells. Collectively, our results present a possible role of f-actin in the SNTA1-Rac1 signaling pathway and implications of actin depolymerization on cell migration, ROS production and apoptosis. PMID:27048259

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

    PubMed

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

    2015-05-01

    This study investigated the short-term toxicity of azoxystrobin (AZ), one of strobilurins used as an effective fungicidal agent to control the Asian soybean rust, on aquatic unicellular algae Chlorella vulgaris. The median percentile inhibition concentration (IC₅₀) of AZ for C. vulgaris was found to be 510 μg L(-1). We showed that the algal cells were obviously depressed or shrunk in 300 and 600 μg L(-1) AZ treatments by using the electron microscopy. Furthermore, 19, 75, and 300 μg L(-1) AZ treatments decreased the soluble protein content and chlorophyll concentrations in C. vulgaris and altered the energy-photosynthesis-related mRNA expression levels in 48- and 96-h exposure periods. Simultaneously, our results showed that AZ could increase the total antioxidant capacity (T-AOC) level and compromise superoxide dismutase (SOD), peroxidase (POD), glutathione S transferase (GST), glutathione peroxidase (GPx) activities, and glutathione (GSH) content. These situations might render C. vulgaris more vulnerable to oxidative damage. Overall, the present study indicated that AZ might be toxic to the growth of C. vulgaris, affect energy-photosynthesis-related mRNA expressions, and induce reactive oxygen species (ROS) overproduction in C. vulgaris. PMID:25672875

  8. The effect of gallic acid on cytotoxicity, Ca(2+) homeostasis and ROS production in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes.

    PubMed

    Hsu, Shu-Shong; Chou, Chiang-Ting; Liao, Wei-Chuan; Shieh, Pochuen; Kuo, Daih-Huang; Kuo, Chun-Chi; Jan, Chung-Ren; Liang, Wei-Zhe

    2016-05-25

    Gallic acid, a polyhydroxylphenolic compound, is widely distributed in various plants, fruits and foods. It has been shown that gallic acid passes into blood brain barrier and reaches the brain tissue of middle cerebral artery occlusion rats. However, the effect of gallic acid on Ca(2+) signaling in glia cells is unknown. This study explored whether gallic acid affected Ca(2+) homeostasis and induced Ca(2+)-associated cytotoxicity in DBTRG-05MG human glioblastoma cells and CTX TNA2 rat astrocytes. Gallic acid (20-40 μM) concentration-dependently induced cytotoxicity and intracellular Ca(2+) level ([Ca(2+)]i) increases in DBTRG-05MG cells but not in CTX TNA2 cells. In DBTRG-05MG cells, the Ca(2+) response was decreased by half by removal of extracellular Ca(2+). In Ca(2+)-containing medium, gallic acid-induced Ca(2+) entry was inhibited by store-operated Ca(2+) channel inhibitors (2-APB, econazole and SKF96365). In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin abolished gallic acid-induced [Ca(2+)]i increases. Conversely, incubation with gallic acid also abolished thapsigargin-induced [Ca(2+)]i increases. Inhibition of phospholipase C with U73122 abolished gallic acid-induced [Ca(2+)]i increases. Gallic acid significantly caused cytotoxicity in DBTRG-05MG cells, which was partially prevented by prechelating cytosolic Ca(2+) with BAPTA-AM. Moreover, gallic acid activated mitochondrial apoptotic pathways that involved ROS production. Together, in DBTRG-05MG cells but not in CTX TNA2 cells, gallic acid induced [Ca(2+)]i increases by causing Ca(2+) entry via 2-APB, econazole and SKF96365-sensitive store-operated Ca(2+) entry, and phospholipase C-dependent release from the endoplasmic reticulum. This Ca(2+) signal subsequently evoked mitochondrial pathways of apoptosis that involved ROS production. PMID:27060209

  9. Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan

    PubMed Central

    Scialò, Filippo; Sriram, Ashwin; Fernández-Ayala, Daniel; Gubina, Nina; Lõhmus, Madis; Nelson, Glyn; Logan, Angela; Cooper, Helen M.; Navas, Plácido; Enríquez, Jose Antonio; Murphy, Michael P.; Sanz, Alberto

    2016-01-01

    Summary Increased production of reactive oxygen species (ROS) has long been considered a cause of aging. However, recent studies have implicated ROS as essential secondary messengers. Here we show that the site of ROS production significantly contributes to their apparent dual nature. We report that ROS increase with age as mitochondrial function deteriorates. However, we also demonstrate that increasing ROS production specifically through respiratory complex I reverse electron transport extends Drosophila lifespan. Reverse electron transport rescued pathogenesis induced by severe oxidative stress, highlighting the importance of the site of ROS production in signaling. Furthermore, preventing ubiquinone reduction, through knockdown of PINK1, shortens lifespan and accelerates aging; phenotypes that are rescued by increasing reverse electron transport. These results illustrate that the source of a ROS signal is vital in determining its effects on cellular physiology and establish that manipulation of ubiquinone redox state is a valid strategy to delay aging. PMID:27076081

  10. Production of hydrogen peroxide and expression of ROS generating genes in peach flower petals in response to host and non-host pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reactive oxygen species (ROS) play dual roles in plant-microbe interactions in that they can either stimulate host resistance or benefit pathogen virulence. Accumulation of ROS was determined in peach petals in response to Monilinia fructicola (a compatible pathogen) and Penicillium digitatum (an i...

  11. Inhibitors of ROS production by the ubiquinone-binding site of mitochondrial complex I identified by chemical screening.

    PubMed

    Orr, Adam L; Ashok, Deepthi; Sarantos, Melissa R; Shi, Tong; Hughes, Robert E; Brand, Martin D

    2013-12-01

    Mitochondrial production of reactive oxygen species is often considered an unavoidable consequence of aerobic metabolism and currently cannot be manipulated without perturbing oxidative phosphorylation. Antioxidants are widely used to suppress effects of reactive oxygen species after formation, but they can never fully prevent immediate effects at the sites of production. To identify site-selective inhibitors of mitochondrial superoxide/H2O2 production that do not interfere with mitochondrial energy metabolism, we developed a robust small-molecule screen and secondary profiling strategy. We describe the discovery and characterization of a compound (N-cyclohexyl-4-(4-nitrophenoxy)benzenesulfonamide; CN-POBS) that selectively inhibits superoxide/H2O2 production from the ubiquinone-binding site of complex I (site I(Q)) with no effects on superoxide/H2O2 production from other sites or on oxidative phosphorylation. Structure/activity studies identified a core structure that is important for potency and selectivity for site I(Q). By employing CN-POBS in mitochondria respiring on NADH-generating substrates, we show that site I(Q) does not produce significant amounts of superoxide/H2O2 during forward electron transport on glutamate plus malate. Our screening platform promises to facilitate further discovery of direct modulators of mitochondrially derived oxidative damage and advance our ability to understand and manipulate mitochondrial reactive oxygen species production under both normal and pathological conditions. PMID:23994103

  12. PPAR Activation Induces M1 Macrophage Polarization via cPLA2-COX-2 Inhibition, Activating ROS Production against Leishmania mexicana

    PubMed Central

    Díaz-Gandarilla, J. A.; Osorio-Trujillo, C.; Hernández-Ramírez, V. I.; Talamás-Rohana, P.

    2013-01-01

    Defence against Leishmania depends upon Th1 inflammatory response and, a major problem in susceptible models, is the turnoff of the leishmanicidal activity of macrophages with IL-10, IL-4, and COX-2 upregulation, as well as immunosuppressive PGE2, all together inhibiting the respiratory burst. Peroxisome proliferator-activated receptors (PPAR) activation is responsible for macrophages polarization on Leishmania susceptible models where microbicide functions are deactivated. In this paper, we demonstrated that, at least for L. mexicana, PPAR activation, mainly PPARγ, induced macrophage activation through their polarization towards M1 profile with the increase of microbicide activity against intracellular pathogen L. mexicana. PPAR activation induced IL-10 downregulation, whereas the production of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6 remained high. Moreover, PPAR agonists treatment induced the deactivation of cPLA2-COX-2-prostaglandins pathway together with an increase in TLR4 expression, all of whose criteria meet the M1 macrophage profile. Finally, parasite burden, in treated macrophages, was lower than that in infected nontreated macrophages, most probably associated with the increase of respiratory burst in these treated cells. Based on the above data, we conclude that PPAR agonists used in this work induces M1 macrophages polarization via inhibition of cPLA2 and the increase of aggressive microbicidal activity via reactive oxygen species (ROS) production. PMID:23555077

  13. Effects of Camphorquinone on Cytotoxicity, Cell Cycle Regulation and Prostaglandin E2 Production of Dental Pulp Cells: Role of ROS, ATM/Chk2, MEK/ERK and Hemeoxygenase-1

    PubMed Central

    Chang, Mei-Chi; Lin, Li-Deh; Wu, Min-Tsz; Chan, Chiu-Po; Chang, Hsiao-Hua; Lee, Ming-Shu; Sun, Tzu-Ying; Jeng, Po-Yuan; Yeung, Sin-Yuet; Lin, Hsueh-Jen; Jeng, Jiiang-Huei

    2015-01-01

    Camphorquinone (CQ) is a popularly-used photosensitizer in composite resin restoration. In this study, the effects of CQ on cytotoxicity and inflammation-related genes and proteins expression of pulp cells were investigated. The role of reactive oxygen species (ROS), ATM/Chk2/p53 and hemeoxygenase-1 (HO-1) and MEK/ERK signaling was also evaluated. We found that ROS and free radicals may play important role in CQ toxicity. CQ (1 and 2 mM) decreased the viability of pulp cells to about 70% and 50% of control, respectively. CQ also induced G2/M cell cycle arrest and apoptosis of pulp cells. The expression of type I collagen, cdc2, cyclin B, and cdc25C was inhibited, while p21, HO-1 and cyclooxygenase-2 (COX-2) were stimulated by CQ. CQ also activated ATM, Chk2, and p53 phosphorylation and GADD45α expression. Besides, exposure to CQ increased cellular ROS level and 8-isoprostane production. CQ also stimulated COX-2 expression and PGE2 production of pulp cells. The reduction of cell viability caused by CQ can be attenuated by N-acetyl-L-cysteine (NAC), catalase and superoxide dismutase (SOD), but can be promoted by Zinc protoporphyin (ZnPP). CQ stimulated ERK1/2 phosphorylation, and U0126 prevented the CQ-induced COX-2 expression and prostaglandin E2 (PGE2) production. These results indicate that CQ may cause cytotoxicity, cell cycle arrest, apoptosis, and PGE2 production of pulp cells. These events could be due to stimulation of ROS and 8-isoprostane production, ATM/Chk2/p53 signaling, HO-1, COX-2 and p21 expression, as well as the inhibition of cdc2, cdc25C and cyclin B1. These results are important for understanding the role of ROS in pathogenesis of pulp necrosis and pulpal inflammation after clinical composite resin filling. PMID:26658076

  14. Effects of Camphorquinone on Cytotoxicity, Cell Cycle Regulation and Prostaglandin E2 Production of Dental Pulp Cells: Role of ROS, ATM/Chk2, MEK/ERK and Hemeoxygenase-1.

    PubMed

    Chang, Mei-Chi; Lin, Li-Deh; Wu, Min-Tsz; Chan, Chiu-Po; Chang, Hsiao-Hua; Lee, Ming-Shu; Sun, Tzu-Ying; Jeng, Po-Yuan; Yeung, Sin-Yuet; Lin, Hsueh-Jen; Jeng, Jiiang-Huei

    2015-01-01

    Camphorquinone (CQ) is a popularly-used photosensitizer in composite resin restoration. In this study, the effects of CQ on cytotoxicity and inflammation-related genes and proteins expression of pulp cells were investigated. The role of reactive oxygen species (ROS), ATM/Chk2/p53 and hemeoxygenase-1 (HO-1) and MEK/ERK signaling was also evaluated. We found that ROS and free radicals may play important role in CQ toxicity. CQ (1 and 2 mM) decreased the viability of pulp cells to about 70% and 50% of control, respectively. CQ also induced G2/M cell cycle arrest and apoptosis of pulp cells. The expression of type I collagen, cdc2, cyclin B, and cdc25C was inhibited, while p21, HO-1 and cyclooxygenase-2 (COX-2) were stimulated by CQ. CQ also activated ATM, Chk2, and p53 phosphorylation and GADD45α expression. Besides, exposure to CQ increased cellular ROS level and 8-isoprostane production. CQ also stimulated COX-2 expression and PGE2 production of pulp cells. The reduction of cell viability caused by CQ can be attenuated by N-acetyl-L-cysteine (NAC), catalase and superoxide dismutase (SOD), but can be promoted by Zinc protoporphyin (ZnPP). CQ stimulated ERK1/2 phosphorylation, and U0126 prevented the CQ-induced COX-2 expression and prostaglandin E2 (PGE2) production. These results indicate that CQ may cause cytotoxicity, cell cycle arrest, apoptosis, and PGE2 production of pulp cells. These events could be due to stimulation of ROS and 8-isoprostane production, ATM/Chk2/p53 signaling, HO-1, COX-2 and p21 expression, as well as the inhibition of cdc2, cdc25C and cyclin B1. These results are important for understanding the role of ROS in pathogenesis of pulp necrosis and pulpal inflammation after clinical composite resin filling. PMID:26658076

  15. Mediating the potent ROS toxicity of acrolein in neurons with silica nanoparticles and a natural product approach

    NASA Astrophysics Data System (ADS)

    White-Schenk, Désirée.; Shi, Riyi; Leary, James F.

    2014-03-01

    Acrolein, a very reactive aldehyde, is a culprit in the biochemical cascade after primary, mechanical spinal cord injury (SCI), which leads to the destruction of tissue initially unharmed, referred to as "secondary injury". Additionally, in models of multiple sclerosis (MS) and some clinical research, acrolein levels are significantly increased. Due to its ability to make more copies of itself in the presence of tissue via lipid peroxidation, researchers believe that acrolein plays a role in the increased destruction of the central nervous system in both SCI and MS. Hydralazine, an FDAapproved hypotensive drug, has been shown to scavenge acrolein, but its side effects and short half life at the appropriate dose for acrolein scavenging must be improved for beneficial clinical translation. Therefore, a nanomedical approach has been designed using silica nanoparticles as a porous delivery vehicle hydralazine. The silica particles are formed in a one-step method that incorporates poly(ethylene) glycol (PEG), a stealth molecule, directly onto the nanoparticles. As an additional avenue for study, a natural product in green tea, epigallocatechin gallate (EGCG), has been explored for its ability to react with acrolein, disabling its reactive capabilities. Upon demonstration of attenuating acrolein, EGCG's delivery may also be improved using the nanomedical approach. The current work exposes the potential of using silica nanoparticles as a delivery vehicle and EGCG's antioxidant capabilities in B35 neuroblastoma cells exposed to acrolein. We also measure nanotoxicity to individual rat neurons using high-throughput image scanning cytometry.

  16. Silencing of the methionine sulfoxide reductase A gene results in loss of mitochondrial membrane potential and increased ROS production in human lens cells

    PubMed Central

    Marchetti, Maria A.; Lee, Wanda; Cowell, Tracy L.; Wells, Tracy M.; Weissbach, Herbert; Kantorow, Marc

    2010-01-01

    Accumulation of methionine sulfoxide (Met(O)) is a significant feature of human cataract and previous studies have shown that methionine sulfoxide reductase A (MsrA), which acts to repair Met(O), can defend human lens cells against oxidative stress induced cell death. A key feature of oxidative stress is increased reactive oxygen species (ROS) in association with loss of mitochondrial function. Here, we sought to establish a potential role for MsrA in the accumulation of ROS in lens cells and the corresponding mitochondrial membrane potential in these cells. Targeted gene silencing was used to establish populations of lens cells expressing different levels of MsrA, and the mitochondrial membrane potential and ROS levels of these cell populations were monitored. Decreased MsrA levels were found to be associated with loss of cell viability, decreased mitochondrial membrane potential, and increased ROS levels in the absence of oxidative stress. These effects were augmented upon oxidative stress treatment. These results provide evidence that MsrA is a major determinant for accumulation of ROS in lens cells and that increased ROS levels in lens cells are associated with a corresponding decrease in mitochondrial membrane potential that is likely related to the requirement for MsrA in lens cell viability. PMID:16934804

  17. Effects of individual and a mixture of pharmaceuticals and personal-care products on cytotoxicity, EROD activity and ROS production in a rainbow trout gonadal cell line (RTG-2).

    PubMed

    Fernández, Carlos; Carbonell, Gregoria; Babín, Mar

    2013-11-01

    The presence of pharmaceuticals and personal-care products (PPCPs) in aquatic environments is of concern. Although measured concentrations of individual substances are low, little consideration has been given to the likely chronic nature of the exposures or to the potential for mixture effects. The purpose of the present study was to use the RTG-2 rainbow trout cell line to analyse sub-lethal and cytotoxic effects of PPCPs present in a wastewater-treatment-plant (WWTP) effluents and their mixtures. Interactions with cytochrome P450 1A enzyme, oxidative stress, cellular senescence and cell viability were assessed using 7-ethoxyresorufin-o-deethylase (EROD), reactive oxygen species (ROS), ß-galactosidase (ß-gal) and neutral red (NR) uptake assays, respectively. Not all of the compounds that were tested exhibited significant effects. The lowest-observed-effect concentrations and half maximal effective concentrations (EC50 ) were within the range 0.15 to 784.47 µg l(-1) . Clear dose-response curves were found for cells exposed to different mixtures of PPCPs. The lowest-observed-effect concentrations and concentrations causing EC50 were within the range 0.05 to 54.61 µg l(-1) . Four out the seven tested mixtures induced EROD activity. ROS production was detected in two mixtures. The ß-gal inhibition response was observed in six out the seven tested mixtures and occurred at a higher concentration than was observed for EROD induction activity or ROS generation. The present study clearly shows that the stress response through which cells mount a homeostatic response to toxicants can be potentially used for an initial, rapid and cost-effective assessment of the complex mixtures of PPCP that present in WWTP effluents are difficult and expensive to analyse chemically. PMID:22718253

  18. A Comparison of B16 Melanoma Cells and 3T3 Fibroblasts Concerning Cell Viability and ROS Production in the Presence of Melatonin, Tested Over a Wide Range of Concentrations.

    PubMed

    Bonmati-Carrion, Maria Angeles; Alvarez-Sánchez, Nuria; Hardeland, Rüdiger; Madrid, Juan Antonio; Rol, Maria Angeles

    2013-01-01

    Melatonin is a pleiotropic molecule with many cellular and systemic actions, including chronobiotic effects. Beneficial effects are widely documented concerning the treatment of neoplastic diseases in vivo as well as reductions in viability of cultured cells from melanoma, one of the most aggressive cancers in humans. However, studies of its effects on non-tumor cells in vitro have not focused on viability, except for experiments aiming to protect against oxidotoxicity or other toxicological insults. Furthermore, there is no agreement on the range of effective melatonin concentrations in vitro, and the mechanisms that reduce cell viability have remained unclear. Tumor cell-specific increases in the production of reactive oxygen and nitrogen species (ROS/RNS) may provide a possible explanation. Our aim was to analyze the potential inhibition of tumor (B16 melanoma 4A5) and non-tumor cell (3T3 Swiss albino) viability using a wide range of melatonin concentrations (10-11-10-2 M), and to determine whether intracellular ROS enhancement was involved in this process. In the absence of fetal bovine serum (FBS), low melatonin concentrations (10-9-10-5 M) reduced the proliferation of melanoma cells with no effect in fibroblasts, whereas, in the presence of FBS, they had no effect or even increased the proliferation of both fibroblast and melanoma cells. Melatonin concentrations in the upper millimolar range increased ROS levels and reduced the viability of both cell types, but more markedly so in non-tumor cells. Thus, low melatonin concentrations reduce proliferation in this specific melanoma cell line, whereas high concentrations affect the viability of both tumor (B16 4A5 melanoma) and non-tumor (3T3 fibroblasts) cells. Increased ROS levels in both lines indicate a role for ROS production in the reduction of cell viability at high-but not low-melatonin concentrations, although the mechanism of action still remains to be elucidated. PMID:23434670

  19. Tetrabromobisphenol A (TBBPA)-stimulated reactive oxygen species (ROS) production in cell-free model using the 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) assay-limitations of method.

    PubMed

    Szychowski, Konrad A; Rybczyńska-Tkaczyk, Kamila; Leja, Marcin L; Wójtowicz, Anna K; Gmiński, Jan

    2016-06-01

    Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant, applied in a variety of commercial and household products, mainly electronic ones. Since the production of reactive oxygen species (ROS) is considered one of the principal cytotoxicity mechanisms, numerous studies undertake that aspect of TBBPA's mechanism of action. The present study verifies if the fluorogenic substrate 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) should be used to detect ROS production induced by TBBPA. To determine the ability of TBBPA alone to stimulate the conversion of H2DCFDA to its fluorescent product 2',7'-dichlorofluorescein (DCF), we used a cell-free model. In the experiments we check different cultured media also in combination with free radical scavenger N-acetyl-l-cysteine (NAC). Additionally, experiments with stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH·) have been made. The presented data showed that TBBPA in all tested concentrations interacts with H2DCFDA in phosphate-buffered saline (PBS) buffer while in micromolar concentrations in the DMEM/F12 medium with and without serum. The addition of NAC inhibited the interaction of TBBPA with H2DCFDA. Experiments with DPPH· showed that, in the presence of NAC, TBBPA acts like a free radical. TBBPA has similar properties to free radical and is susceptible to free radical scavenging properties of NAC. Our results indicated that H2DCFDA assay cannot be used to evaluate cellular ROS production in TBBPA studies. The study connected with TBBPA-stimulated ROS production in cell culture models using the H2DCFDA assay should be revised using a different method. However, due to the free radical-like nature of TBBPA, it can be very difficult. Therefore, further investigation of the nature of TBBPA as a compound with similar properties to free radical is required. PMID:26976009

  20. Activation of the ACE2/Ang-(1-7)/Mas pathway reduces oxygen-glucose deprivation induced tissue swelling, ROS production, and cell death in mouse brain with angiotensin II overproduction

    PubMed Central

    Zheng, Jiaolin; Li, Guangze; Chen, Shuzhen; Chen, Ji; Buck, Joshua; Zhu, Yulan; Xia, Huijing; Lazartigues, Eric; Chen, Yanfang; Olson, James E.

    2014-01-01

    We previously demonstrated that mice which overexpress human renin and angiotensinogen (R+A+) show enhanced cerebral damage in both in vivo and in vitro experimental ischemia models. Angiotensin converting enzyme 2 (ACE2) counteracts the effects of angiotensin (Ang-II) by transforming it into Ang-(1-7), thus reducing the ligand for the AT1 receptor and increasing stimulation of the Mas receptor. Triple transgenic mice, SARA, which specifically overexpress ACE2 in neurons of R+A+ mice were used to study the role of ACE2 in ischemic stroke using oxygen and glucose deprivation (OGD) of brain slices as an in vitro model. We examined tissue swelling, the production of reactive oxygen species (ROS), and cell death in cerebral cortex (CX) and the hippocampal CA1 region during OGD. Expression levels of NADPH oxidase isoforms, Nox2 and Nox4 were measured using western blots. Results show that SARA mice and R+A+ mice treated with the Mas receptor agonist Ang-(1-7) had less swelling, cell death, and ROS production in CX and CA1 areas compared to those in R+A+ animals. Treatment of slices from SARA mice with the Mas antagonist A779 eliminated this protection. Finally, western blots revealed less Nox2 and Nox4 expression in SARA mice compared with R+A+ mice both before and after OGD. We suggest that reduced brain swelling and cell death observed in SARA animals exposed to OGD results from diminished ROS production coupled with lower expression of NADPH oxidases. Thus, the ACE2/Ang-(1-7)/Mas receptor pathway plays a protective role in brain ischemic damage by counteracting the detrimental effects of Ang-II-induced ROS production. PMID:24814023

  1. Activation of the ACE2/Ang-(1-7)/Mas pathway reduces oxygen-glucose deprivation-induced tissue swelling, ROS production, and cell death in mouse brain with angiotensin II overproduction.

    PubMed

    Zheng, J; Li, G; Chen, S; Bihl, J; Buck, J; Zhu, Y; Xia, H; Lazartigues, E; Chen, Y; Olson, J E

    2014-07-25

    We previously demonstrated that mice which overexpress human renin and angiotensinogen (R+A+) show enhanced cerebral damage in both in vivo and in vitro experimental ischemia models. Angiotensin-converting enzyme 2 (ACE2) counteracts the effects of angiotensin (Ang-II) by transforming it into Ang-(1-7), thus reducing the ligand for the AT1 receptor and increasing stimulation of the Mas receptor. Triple transgenic mice, SARA, which specifically overexpress ACE2 in neurons of R+A+ mice were used to study the role of ACE2 in ischemic stroke using oxygen and glucose deprivation (OGD) of brain slices as an in vitro model. We examined tissue swelling, the production of reactive oxygen species (ROS), and cell death in the cerebral cortex (CX) and the hippocampal CA1 region during OGD. Expression levels of NADPH oxidase (Nox) isoforms, Nox2 and Nox4 were measured using western blots. Results show that SARA mice and R+A+ mice treated with the Mas receptor agonist Ang-(1-7) had less swelling, cell death, and ROS production in CX and CA1 areas compared to those in R+A+ animals. Treatment of slices from SARA mice with the Mas antagonist A779 eliminated this protection. Finally, western blots revealed less Nox2 and Nox4 expression in SARA mice compared with R+A+ mice both before and after OGD. We suggest that reduced brain swelling and cell death observed in SARA animals exposed to OGD result from diminished ROS production coupled with lower expression of Nox isoforms. Thus, the ACE2/Ang-(1-7)/Mas receptor pathway plays a protective role in brain ischemic damage by counteracting the detrimental effects of Ang-II-induced ROS production. PMID:24814023

  2. Reactive oxygen species (ROS) production triggered by prostaglandin D2 (PGD2) regulates lactate dehydrogenase (LDH) expression/activity in TM4 Sertoli cells.

    PubMed

    Rossi, Soledad P; Windschüttl, Stefanie; Matzkin, María E; Rey-Ares, Verónica; Terradas, Claudio; Ponzio, Roberto; Puigdomenech, Elisa; Levalle, Oscar; Calandra, Ricardo S; Mayerhofer, Artur; Frungieri, Mónica B

    2016-10-15

    Reactive oxygen species (ROS) regulate testicular function in health and disease. We previously described a prostaglandin D2 (PGD2) system in Sertoli cells. Now, we found that PGD2 increases ROS and hydrogen peroxide (H2O2) generation in murine TM4 Sertoli cells, and also induces antioxidant enzymes expression suggesting that defense systems are triggered as an adaptive stress mechanism that guarantees cell survival. ROS and specially H2O2 may act as second messengers regulating signal transduction pathways and gene expression. We describe a stimulatory effect of PGD2 on lactate dehydrogenase (LDH) expression via DP1/DP2 receptors, which is prevented by the antioxidant N-acetyl-L-cysteine and the PI3K/Akt pathway inhibitor LY 294002. PGD2 also enhances Akt and CREB/ATF-1 phosphorylation. Our results provide evidence for a role of PGD2 in the regulation of the oxidant/antioxidant status in Sertoli cells and, more importantly, in the modulation of LDH expression which takes place through ROS generation and the Akt-CREB/ATF-1 pathway. PMID:27329155

  3. Mitochondrial flashes: new insights into mitochondrial ROS signalling and beyond.

    PubMed

    Hou, Tingting; Wang, Xianhua; Ma, Qi; Cheng, Heping

    2014-09-01

    Respiratory mitochondria undergo stochastic, intermittent bursts of superoxide production accompanied by transient depolarization of the mitochondrial membrane potential and reversible opening of the membrane permeability transition pore. These discrete events were named 'superoxide flashes' for the reactive oxygen species (ROS) signal involved, and 'mitochondrial flashes' (mitoflashes) for the entirety of the multifaceted and intertwined mitochondrial processes. In contrast to the flashless basal ROS production of 'homeostatic ROS' for redox regulation, bursting ROS production during mitoflashes may provide 'signalling ROS' at the organelle level, fulfilling distinctly different cell functions. Mounting evidence indicates that mitoflash frequency is richly regulated over a broad range, and represents a novel, universal, and 'digital' readout of mitochondrial functional status and of the mitochondrial stress response. An emerging view is that mitoflashes participate in vital processes including metabolism, cell differentiation, the stress response and ageing. These recent advances shed new light on the role of mitochondrial functional dynamics in health and disease. PMID:25038239

  4. Rapamycin reverses age-related increases in mitochondrial ROS production at complex I, oxidative stress, accumulation of mtDNA fragments inside nuclear DNA, and lipofuscin level, and increases autophagy, in the liver of middle-aged mice.

    PubMed

    Martínez-Cisuelo, V; Gómez, J; García-Junceda, I; Naudí, A; Cabré, R; Mota-Martorell, N; López-Torres, M; González-Sánchez, M; Pamplona, R; Barja, G

    2016-10-01

    Rapamycin consistently increases longevity in mice although the mechanism of action of this drug is unknown. In the present investigation we studied the effect of rapamycin on mitochondrial oxidative stress at the same dose that is known to increase longevity in mice (14mgofrapamycin/kg of diet). Middle aged mice (16months old) showed significant age-related increases in mitochondrial ROS production at complex I, accumulation of mtDNA fragments inside nuclear DNA, mitochondrial protein lipoxidation, and lipofuscin accumulation compared to young animals (4months old) in the liver. After 7weeks of dietary treatment all those increases were totally or partially (lipofuscin) abolished by rapamycin, middle aged rapamycin-treated animals showing similar levels in those parameters to young animals. The decrease in mitochondrial ROS production was due to qualitative instead of quantitative changes in complex I. The decrease in mitochondrial protein lipoxidation was not due to decreases in the amount of highly oxidizable unsaturated fatty acids. Rapamycin also decreased the amount of RAPTOR (of mTOR complex) and increased the amounts of the PGC1-α and ATG13 proteins. The results are consistent with the possibility that rapamycin increases longevity in mice at least in part by lowering mitochondrial ROS production and increasing autophagy, decreasing the derived final forms of damage accumulated with age which are responsible for increased longevity. The decrease in lipofuscin accumulation induced by rapamycin adds to previous information suggesting that the increase in longevity induced by this drug can be due to a decrease in the rate of aging. PMID:27498120

  5. Female protection from slow-pressor effects of AngII involves prevention of ROS production independent of NMDA receptor trafficking in hypothalamic neurons expressing angiotensin-1A receptors

    PubMed Central

    Marques-Lopes, Jose; Lynch, Mary-Katherine; Van Kempen, Tracey A.; Waters, Elizabeth M.; Wang, Gang; Iadecola, Costantino; Pickel, Virginia M.; Milner, Teresa A.

    2014-01-01

    Renin-angiotensin system over-activity, up-regulation of post-synaptic NMDA receptor function, and increased reactive oxygen species (ROS) production in the hypothalamic paraventricular nucleus (PVN) are hallmarks of angiotensin II (AngII)-induced hypertension, which is far more common in young males than in young females. We hypothesize that the sex differences in hypertension are related to differential AngII-induced changes in post-synaptic trafficking of the essential NMDA receptor GluN1 subunit and ROS production in PVN cells expressing angiotensin type 1a receptor (AT1aR). We tested this hypothesis using slow-pressor (14 day) infusion of AngII (600ng/kg/min) in mice, which elicits hypertension in males but not in young females. Two month-old male and female transgenic mice expressing enhanced green fluorescent protein (EGFP) in AT1aR-containing cells were used. In males, but not females, AngII increased blood pressure and ROS production in AT1aR-EGFP PVN cells at baseline and following NMDA treatment. Electron microscopy showed that AngII increased cytoplasmic and total GluN1-silver-intensified immunogold (SIG) densities, and induced a trend towards an increase in near plasmalemmal GluN1-SIG density in AT1aR-EGFP dendrites of males and females. Moreover, AngII decreased dendritic area and diameter in males, but increased dendritic area of small (<1μm) dendrites and decreased diameter of large (>1μm) dendrites in females. Fluorescence microscopy revealed that AT1aR and estrogen receptor β do not co-localize suggesting that, if estrogen is involved, its effect is indirect. The data suggest that the sexual dimorphism in AngII-induced hypertension is associated with sex differences in ROS production in AT1aR-containing PVN cells, but not with post-synaptic NMDA receptor trafficking. PMID:25559190

  6. Genetic disorders coupled to ROS deficiency.

    PubMed

    O'Neill, Sharon; Brault, Julie; Stasia, Marie-Jose; Knaus, Ulla G

    2015-12-01

    Maintaining the redox balance between generation and elimination of reactive oxygen species (ROS) is critical for health. Disturbances such as continuously elevated ROS levels will result in oxidative stress and development of disease, but likewise, insufficient ROS production will be detrimental to health. Reduced or even complete loss of ROS generation originates mainly from inactivating variants in genes encoding for NADPH oxidase complexes. In particular, deficiency in phagocyte Nox2 oxidase function due to genetic variants (CYBB, CYBA, NCF1, NCF2, NCF4) has been recognized as a direct cause of chronic granulomatous disease (CGD), an inherited immune disorder. More recently, additional diseases have been linked to functionally altered variants in genes encoding for other NADPH oxidases, such as for DUOX2/DUOXA2 in congenital hypothyroidism, or for the Nox2 complex, NOX1 and DUOX2 as risk factors for inflammatory bowel disease. A comprehensive overview of novel developments in terms of Nox/Duox-deficiency disorders is presented, combined with insights gained from structure-function studies that will aid in predicting functional defects of clinical variants. PMID:26210446

  7. Genetic disorders coupled to ROS deficiency

    PubMed Central

    O’Neill, Sharon; Brault, Julie; Stasia, Marie-Jose; Knaus, Ulla G.

    2015-01-01

    Maintaining the redox balance between generation and elimination of reactive oxygen species (ROS) is critical for health. Disturbances such as continuously elevated ROS levels will result in oxidative stress and development of disease, but likewise, insufficient ROS production will be detrimental to health. Reduced or even complete loss of ROS generation originates mainly from inactivating variants in genes encoding for NADPH oxidase complexes. In particular, deficiency in phagocyte Nox2 oxidase function due to genetic variants (CYBB, CYBA, NCF1, NCF2, NCF4) has been recognized as a direct cause of chronic granulomatous disease (CGD), an inherited immune disorder. More recently, additional diseases have been linked to functionally altered variants in genes encoding for other NADPH oxidases, such as for DUOX2/DUOXA2 in congenital hypothyroidism, or for the Nox2 complex, NOX1 and DUOX2 as risk factors for inflammatory bowel disease. A comprehensive overview of novel developments in terms of Nox/Duox-deficiency disorders is presented, combined with insights gained from structure–function studies that will aid in predicting functional defects of clinical variants. PMID:26210446

  8. The interplay between ROS and tubulin cytoskeleton in plants

    PubMed Central

    Livanos, Pantelis; Galatis, Basil; Apostolakos, Panagiotis

    2014-01-01

    Plants have to deal with reactive oxygen species (ROS) production, since it could potentially cause severe damages to different cellular components. On the other hand, ROS functioning as important second messengers are implicated in various developmental processes and are transiently produced during biotic or abiotic stresses. Furthermore, the microtubules (MTs) play a primary role in plant development and appear as potent players in sensing stressful situations and in the subsequent cellular responses. Emerging evidence suggests that ROS affect MTs in multiple ways. The cellular redox status seems to be tightly coupled with MTs. ROS signals regulate the organization of tubulin cytoskeleton and induce tubulin modifications. This review aims at summarizing the signaling mechanisms and the key operators orchestrating the crosstalk between ROS and tubulin cytoskeleton in plant cells. The contribution of several molecules, including microtubule associated proteins, oxidases, kinases, phospholipases, and transcription factors, is highlighted. PMID:24521945

  9. CIRCADIAN CLOCK-ASSOCIATED 1 regulates ROS homeostasis and oxidative stress responses

    PubMed Central

    Lai, Alvina Grace; Doherty, Colleen J.; Mueller-Roeber, Bernd; Kay, Steve A.; Schippers, Jos H. M.; Dijkwel, Paul P.

    2012-01-01

    Organisms have evolved endogenous biological clocks as internal timekeepers to coordinate metabolic processes with the external environment. Here, we seek to understand the mechanism of synchrony between the oscillator and products of metabolism known as Reactive Oxygen Species (ROS) in Arabidopsis thaliana. ROS-responsive genes exhibit a time-of-day–specific phase of expression under diurnal and circadian conditions, implying a role of the circadian clock in transcriptional regulation of these genes. Hydrogen peroxide production and scavenging also display time-of-day phases. Mutations in the core-clock regulator, CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), affect the transcriptional regulation of ROS-responsive genes, ROS homeostasis, and tolerance to oxidative stress. Mis-expression of EARLY FLOWERING 3, LUX ARRHYTHMO, and TIMING OF CAB EXPRESSION 1 affect ROS production and transcription, indicating a global effect of the clock on the ROS network. We propose CCA1 as a master regulator of ROS homeostasis through association with the Evening Element in promoters of ROS genes in vivo to coordinate time-dependent responses to oxidative stress. We also find that ROS functions as an input signal that affects the transcriptional output of the clock, revealing an important link between ROS signaling and circadian output. Temporal coordination of ROS signaling by CCA1 and the reciprocal control of circadian output by ROS reveal a mechanistic link that allows plants to master oxidative stress responses. PMID:23027948

  10. Palmitic acid induces interleukin-1β secretion via NLRP3 inflammasomes and inflammatory responses through ROS production in human placental cells.

    PubMed

    Shirasuna, Koumei; Takano, Hiroki; Seno, Kotomi; Ohtsu, Ayaka; Karasawa, Tadayoshi; Takahashi, Masafumi; Ohkuchi, Akihide; Suzuki, Hirotada; Matsubara, Shigeki; Iwata, Hisataka; Kuwayama, Takehito

    2016-08-01

    Maternal obesity, a major risk factor for adverse pregnancy complications, results in inflammatory cytokine release in the placenta. Levels of free fatty acids are elevated in the plasma of obese human. These fatty acids include obesity-related palmitic acids, which is a major saturated fatty acid, that promotes inflammatory responses. Increasing evidence indicates that nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasomes mediate inflammatory responses induced by endogenous danger signals. We hypothesized that inflammatory responses associated with gestational obesity cause inflammation. To test this hypothesis, we investigated the effect of palmitic acid on the activation of NLRP3 inflammasomes and inflammatory responses in a human Sw.71 trophoblast cell line. Palmitic acid stimulated caspase-1 activation and markedly increased interleukin (IL)-1β secretion in Sw.71 cells. Treatment with a caspase-1 inhibitor diminished palmitic acid-induced IL-1β release. In addition, NLRP3 and caspase-1 genome editing using a CRISPR/Cas9 system in Sw.71 cells suppressed IL-1β secretion, which was stimulated by palmitic acid. Moreover, palmitic acid stimulated caspase-3 activation and inflammatory cytokine secretion (e.g., IL-6 and IL-8). Palmitic acid-induced cytokine secretion were dependent on caspase-3 activation. In addition, palmitic acid-induced IL-1β, IL-6, and IL-8 secretion was depended on reactive oxygen species (ROS) generation. In conclusion, palmitic acid caused activation of NLRP3 inflammasomes and inflammatory responses, inducing IL-1β, IL-6, and IL-8 secretion, which is associated with ROS generation, in human Sw.71 placental cells. We suggest that obesity-related palmitic acid induces placental inflammation, resulting in association with pregnancy complications. PMID:27300134

  11. Phytohormones Signaling Pathways and ROS Involvement in Seed Germination

    PubMed Central

    Oracz, Krystyna; Karpiński, Stanisław

    2016-01-01

    Phytohormones and reactive oxygen species (ROS) are major determinants of the regulation of development and stress responses in plants. During life cycle of these organisms, signaling networks of plant growth regulators and ROS interact in order to render an appropriate developmental and environmental response. In plant’s photosynthetic (e.g., leaves) and non-photosynthetic (e.g., seeds) tissues, enhanced and suboptimal ROS production is usually associated with stress, which in extreme cases can be lethal to cells, a whole organ or even an organism. However, controlled production of ROS is appreciated for cellular signaling. Despite the current progress that has been made in plant biology and increasing number of findings that have revealed roles of ROS and hormonal signaling in germination, some questions still arise, e.g., what are the downstream protein targets modified by ROS enabling stimulus-specific cellular responses of the seed? Or which molecular regulators allow ROS/phytohormones interactions and what is their function in seed life? In this particular review the role of some transcription factors, kinases and phosphatases is discussed, especially those which usually known to be involved in ROS and hormonal signal transduction under stress in plants, may also play a role in the regulation of processes occurring in seeds. The summarized recent findings regarding particular ROS- and phytohormones-related regulatory proteins, as well as their integration, allowed to propose a novel, possible model of action of LESION SIMULATING DISEASE 1, ENHANCED DISEASE SUSCEPTIBILITY 1, and PHYTOALEXIN DEFICIENT 4 functioning during seeds life. PMID:27379144

  12. Fibulin-5 Blocks Microenvironmental ROS in Pancreatic Cancer.

    PubMed

    Wang, Miao; Topalovski, Mary; Toombs, Jason E; Wright, Christopher M; Moore, Zachary R; Boothman, David A; Yanagisawa, Hiromi; Wang, Huamin; Witkiewicz, Agnieszka; Castrillon, Diego H; Brekken, Rolf A

    2015-12-01

    Elevated oxidative stress is an aberration seen in many solid tumors, and exploiting this biochemical difference has the potential to enhance the efficacy of anticancer agents. Homeostasis of reactive oxygen species (ROS) is important for normal cell function, but excessive production of ROS can result in cellular toxicity, and therefore ROS levels must be balanced finely. Here, we highlight the relationship between the extracellular matrix and ROS production by reporting a novel function of the matricellular protein Fibulin-5 (Fbln5). We used genetically engineered mouse models of pancreatic ductal adenocarcinoma (PDAC) and found that mutation of the integrin-binding domain of Fbln5 led to decreased tumor growth, increased survival, and enhanced chemoresponse to standard PDAC therapies. Through mechanistic investigations, we found that improved survival was due to increased levels of oxidative stress in Fbln5-mutant tumors. Furthermore, loss of the Fbln5-integrin interaction augmented fibronectin signaling, driving integrin-induced ROS production in a 5-lipooxygenase-dependent manner. These data indicate that Fbln5 promotes PDAC progression by functioning as a molecular rheostat that modulates cell-ECM interactions to reduce ROS production, and thus tip the balance in favor of tumor cell survival and treatment-refractory disease. PMID:26577699

  13. 8,8'-Bieckol, isolated from edible brown algae, exerts its anti-inflammatory effects through inhibition of NF-κB signaling and ROS production in LPS-stimulated macrophages.

    PubMed

    Yang, Yeong-In; Jung, Seung-Hyun; Lee, Kyung-Tae; Choi, Jung-Hye

    2014-12-01

    Ecklonia cava (E. cava) is an abundant brown alga that contains high levels of phlorotannins, which are unique marine polyphenolic compounds. It has been suggested that E. cava phlorotannins exert anti-inflammatory effects. However, the anti-inflammatory effects and underlying molecular mechanism exerted by 8,8'-bieckol isolated from E. cava have not been reported. Thus, in this study, we examined the anti-inflammatory effects of 8,8'-bieckol on lipopolysaccharide (LPS)-stimulated primary macrophages and RAW 264.7 macrophages. We found that 8,8'-bieckol suppressed key inflammatory mediator [i.e., nitric oxide (NO) and prostaglandin E2 (PGE2)] production in both primary and RAW 264.7 macrophages. 8,8'-Bieckol inhibited NO by suppressing LPS-induced expression of inducible nitric oxide synthase (iNOS) at the mRNA and protein levels in primary macrophages and RAW 264.7 cells. In addition, 8,8'-bieckol decreased the production and mRNA expression of the inflammatory cytokine interleukin-6 (IL-6), but not tumor necrosis factor (TNF)-α, in RAW 264.7 cells. Moreover, 8,8'-bieckol treatment diminished transactivation of nuclear factor-kappa B (NF-κB) and nuclear translocation of the NF-κB p65 subunit and suppressed LPS-induced intracellular reactive oxygen species (ROS) production in macrophages. Furthermore, 8,8'-bieckol markedly reduced mortality in LPS-induced septic mice. Taken together, these data indicate that the anti-inflammatory properties of 8,8'-bieckol are associated with the suppression of NO, PGE2, and IL-6 via negative regulation of the NF-κB pathway and ROS production in LPS-stimulated RAW 264.7 cells. Moreover, 8,8'-bieckol protects mice from endotoxin shock. PMID:25261704

  14. Curcumin Ameliorates Furazolidone-Induced DNA Damage and Apoptosis in Human Hepatocyte L02 Cells by Inhibiting ROS Production and Mitochondrial Pathway.

    PubMed

    Dai, Chongshan; Li, Daowen; Gong, Lijing; Xiao, Xilong; Tang, Shusheng

    2016-01-01

    Furazolidone (FZD), a synthetic nitrofuran derivative, has been widely used as an antibacterial and antiprotozoal agent. Recently, the potential toxicity of FZD has raised concerns, but its mechanism is still unclear. This study aimed to investigate the protective effect of curcumin on FZD-induced cytotoxicity and the underlying mechanism in human hepatocyte L02 cells. The results showed that curcumin pre-treatment significantly ameliorated FZD-induced oxidative stress, characterized by decreased reactive oxygen species (ROS) and malondialdehyde formation, and increased superoxide dismutase, catalase activities and glutathione contents. In addition, curcumin pre-treatment significantly ameliorated the loss of mitochondrial membrane potential, the activations of caspase-9 and -3, and apoptosis caused by FZD. Alkaline comet assay showed that curcumin markedly reduced FZD-induced DNA damage in a dose-dependent manner. Curcumin pre-treatment consistently and markedly down-regulated the mRNA expression levels of p53, Bax, caspase-9 and -3 and up-regulated the mRNA expression level of Bcl-2. Taken together, these results reveal that curcumin protects against FZD-induced DNA damage and apoptosis by inhibiting oxidative stress and mitochondrial pathway. Our study indicated that curcumin may be a promising combiner with FZD to reduce FZD-related toxicity in clinical applications. PMID:27556439

  15. Oxidative metabolism, ROS and NO under oxygen deprivation.

    PubMed

    Blokhina, Olga; Fagerstedt, Kurt V

    2010-05-01

    Oxygen deprivation, in line with other stress conditions, is accompanied by reactive oxygen (ROS) and nitrogen species (RNS) formation and is characterised by a set of metabolic changes collectively named as the 'oxidative stress response'. The controversial induction of oxidative metabolism under the lack of oxygen is necessitated by ROS and RNS signaling in the induction of adaptive responses, and inevitably results in oxidative damage. To prevent detrimental effects of oxidative stress, the levels of ROS and NO are tightly controlled on transcriptional, translational and metabolic levels. Hypoxia triggers the induction of genes responsible for ROS and NO handling and utilization (respiratory burst oxidase, non-symbiotic hemoglobins, several cytochromes P450, mitochondrial dehydrogenases, and antioxidant-related transcripts). The level of oxygen in the tissue is also under metabolic control via multiple mechanisms: Regulation of glycolytic and fermentation pathways to manage pyruvate availability for respiration, and adjustment of mitochondrial electron flow through NO and ROS balance. Both adaptive strategies are controlled by energy status and aim to decrease the respiratory capacity and to postpone complete anoxia. Besides local oxygen concentration, ROS and RNS formation is controlled by an array of antioxidants. Hypoxic treatment leads to the upregulation of multiple transcripts associated with ascorbate, glutathione and thioredoxin metabolism. The production of ROS and NO is an integral part of the response to oxygen deprivation which encompasses several levels of metabolic regulation to sustain redox signaling and to prevent oxidative damage. PMID:20303775

  16. Cloning and characterization of two lipopolysaccharide-binding protein/bactericidal permeability-increasing protein (LBP/BPI) genes from the sea cucumber Apostichopus japonicus with diversified function in modulating ROS production.

    PubMed

    Shao, Yina; Li, Chenghua; Che, Zhongjie; Zhang, Pengjuan; Zhang, Weiwei; Duan, Xuemei; Li, Ye

    2015-09-01

    Lipopolysaccharide-binding protein and bactericidal permeability-increasing protein (LBP/BPI) play crucial role in modulating cellular signals in response to Gram-negative bacteria infection. In the present study, two isoforms of LBP/BPI genes (designated as AjLBP/BPI1 and AjLBP/BPI2, respectively) were cloned from the sea cucumber Apostichopus japonicus by RACE approach. The full-length cDNAs of AjLBP/BPI1 and AjLBP/BPI2 were of 1479 and 1455 bp and encoded two secreted proteins of 492 and 484 amino acid residues, respectively. Signal peptide, two BPI/LBP/CETP and one central domain were totally conserved in the deduced amino acid of AjLBP/BPI1 and AjLBP/BPI2. Phylogentic analysis further supported that AjLBP/BPI1 and AjLBP/BPI2 belonged to new members of invertebrates LBP/BPI family. Spatial expression analysis revealed that both AjLBP/BPI1 and AjLBP/BPI2 were ubiquitously expressed in all examined tissues with the larger magnitude in AjLBP/BPI1. The Vibrio splenfidus challenge and LPS stimulation could significantly up-regulate the mRNA expression of both AjLBP/BPI1 and AjLBP/BPI2, with the increase of AjLBP/BPI2 expression occurred earlier than that of AjLBP/BPI1. More importantly, we found that LPS induced ROS production was markedly depressed after AjLBP/BPI1 knock-down, but there was no significant change by AjLBP/BPI2 silencing. Consistently, the expression level of unclassified AjToll, not AjTLR3, was tightly correlated with that of AjLBP/BPI1. Silencing the AjToll also depressed the ROS production in the cultured coelomocytes. All these results indicated that AjLBP/BPI1 and AjLBP/BPI2 probably played distinct roles in bacterial mediating immune response in sea cucumber, and AjLBP/BPI1 depressed coelomocytes ROS production via modulating AjToll cascade. PMID:25956196

  17. ROS and RNS in plant physiology: an overview.

    PubMed

    Del Río, Luis A

    2015-05-01

    The production of reactive oxygen species (ROS) is the unavoidable consequence of aerobic life. ROS is a collective term that includes both oxygen radicals, like superoxide (O 2. -) and hydroxyl (·OH) radicals, and other non-radicals such as hydrogen peroxide (H2O2), singlet oxygen ((1)O2 or (1)Δg), etc. In plants, ROS are produced in different cell compartments and are oxidizing species, particularly hydroxyl radicals and singlet oxygen, that can produce serious damage in biological systems (oxidative stress). However, plant cells also have an array of antioxidants which, normally, can scavenge the excess oxidants produced and so avoid deleterious effects on the plant cell bio-molecules. The concept of 'oxidative stress' was re-evaluated in recent years and the term 'oxidative signalling' was created. This means that ROS production, apart from being a potentially harmful process, is also an important component of the signalling network that plants use for their development and for responding to environmental challenges. It is known that ROS play an important role regulating numerous biological processes such as growth, development, response to biotic and environmental stresses, and programmed cell death. The term reactive nitrogen species (RNS) includes radicals like nitric oxide (NO· ) and nitric dioxide (NO2.), as well as non-radicals such as nitrous acid (HNO2) and dinitrogen tetroxide (N2O4), among others. RNS are also produced in plants although the generating systems have still not been fully characterized. Nitric oxide (NO·) has an important function as a key signalling molecule in plant growth, development, and senescence, and RNS, like ROS, also play an important role as signalling molecules in the response to environmental (abiotic) stress. Similarly, NO· is a key mediator, in co-operation with ROS, in the defence response to pathogen attacks in plants. ROS and RNS have been demonstrated to have an increasingly important role in biology and medicine

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

    PubMed

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

    2014-01-01

    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 β-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 μM) 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

  19. Extracellular polysaccharide from Bacillus sp. strain LBP32 prevents LPS-induced inflammation in RAW 264.7 macrophages by inhibiting NF-κB and MAPKs activation and ROS production.

    PubMed

    Diao, Ying; Xin, Yinqiang; Zhou, Yi; Li, Na; Pan, Xiaolong; Qi, Shimei; Qi, Zhilin; Xu, Yimiao; Luo, Lan; Wan, Honggui; Lan, Lei; Yin, Zhimin

    2014-01-01

    Extracellular polysaccharides (EPSs) are high-molecular weight sugar-based polymers that are synthesized and secreted by many microorganisms. Recently, EPSs have attracted particular attention due to their multiple biological functions including anti-inflammation. However, studies rarely reported the molecular mechanisms underlying their functions. We previously purified an EPS from an oligotrophic bacteria (Bacillus sp. LBP32) found in Lop Nur Desert, which possesses a potent antioxidant activity, while the anti-inflammatory effects of EPS and signaling mechanisms underlying its action have not been clarified. In this study, we demonstrated that EPS significantly inhibited the LPS-induced release of pro-inflammatory mediators, such as nitric oxide (NO), IL-6 and TNF-α, without any significant cytotoxicity. EPS also downregulated the expression of nitric oxide synthase (iNOS) induced by LPS. Furthermore, activation of nuclear factor κB (NF-κB) was abrogated by EPS through inhibited the phosphorylation of IκB kinase (IKK). Activations of Mitogen-activated protein kinases (MAPKs), including p38 MAPK and c-Jun N-terminal kinase (JNK), were also found to be inhibited by EPS. In addition, the level of intracellular reactive oxygen species (ROS) was also significantly decreased with the treatment of EPS. In vivo experiments were conducted and showed that EPS could greatly improve the outcome of mice with LPS-induced endotoxic shock. Taken together, our data indicate that EPS prevents LPS-induced inflammatory response by inhibiting NF-κB and MAPKs activation and ROS production. PMID:24201081

  20. PO2 Cycling Reduces Diaphragm Fatigue by Attenuating ROS Formation

    PubMed Central

    Zuo, Li; Diaz, Philip T.; Chien, Michael T.; Roberts, William J.; Kishek, Juliana; Best, Thomas M.; Wagner, Peter D.

    2014-01-01

    Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses. PMID:25299212

  1. TPD52L1-ROS1, a new ROS1 fusion variant in lung adenosquamous cell carcinoma identified by comprehensive genomic profiling.

    PubMed

    Zhu, Viola Weijia; Upadhyay, Daya; Schrock, Alexa B; Gowen, Kyle; Ali, Siraj M; Ou, Sai-Hong Ignatius

    2016-07-01

    Crizotinib was approved for the treatment of ROS1-rearranged non-small cell lung cancer (NSCLC) patients in the US on 11 March, 2016. Interestingly no one companion diagnostic test (CDx) has been approved simultaneously with this approval of crizotinib. Hence, an ideal and adequate CDx will have to be able to identify ROS1 fusions without the knowledge of the fusion partners to ROS1, and as to date there are 13 fusion partners reported for ROS1 in NSCLC. Here we report a novel TPD52L1-ROS1 fusion variant in NSCLC. This novel TPD52L1-ROS1 fusion variant is generated by the fusion of exons 1-3 of TPD52L1 on chromosome 6q22-23 to the exons 33-43 of ROS1 on chromosome 6q22, likely from an intra-chromosomal deletion and subsequent fusion event similar to the generation of EML4-ALK. The predicted TPD52L1-ROS1 protein product contains 655 amino acids comprising of the N-terminal amino acids 1-95 of TPD52L1 and C-terminal amino acids of 1789-2348 of ROS1. In summary, TPD52L1-ROS1 is a novel ROS1 fusion variant in NSCLC identified by comprehensive genomic profiling and should be included in any ROS1 detecting assays that depend on identifying the corresponding fusion partners, such as reverse transcriptase-polymerase chain reaction (RT-PCR). PMID:27237027

  2. ROS production in homogenate from the body wall of sea cucumber Stichopus japonicus under UVA irradiation: ESR spin-trapping study.

    PubMed

    Qi, Hang; Dong, Xiu-fang; Zhao, Ya-ping; Li, Nan; Fu, Hui; Feng, Ding-ding; Liu, Li; Yu, Chen-xu

    2016-02-01

    Sea cucumber Stichopus japonicus (S. japonicus) shows a strong ability of autolysis, which leads to severe deterioration in sea cucumber quality during processing and storage. In this study, to further characterize the mechanism of sea cucumber autolysis, hydroxyl radical production induced by ultraviolet A (UVA) irradiation was investigated. Homogenate from the body wall of S. japonicas was prepared and subjected to UVA irradiation at room temperature. Electron Spin Resonance (ESR) spectra of the treated samples were subsequently recorded. The results showed that hydroxyl radicals (OH) became more abundant while the time of UVA treatment and the homogenate concentration were increased. Addition of superoxide dismutase (SOD), catalase, EDTA, desferal, NaN3 and D2O to the homogenate samples led to different degrees of inhibition on OH production. Metal cations and pH also showed different effects on OH production. These results indicated that OH was produced in the homogenate with a possible pathway as follows: O2(-) → H2O2 → OH, suggesting that OH might be a critical factor in UVA-induced S. japonicus autolysis. PMID:26304359

  3. Testing the oxidative stress hypothesis of aging in primate fibroblasts: is there a correlation between species longevity and cellular ROS production?

    PubMed

    Csiszar, Anna; Podlutsky, Andrej; Podlutskaya, Natalia; Sonntag, William E; Merlin, Steven Z; Philipp, Eva E R; Doyle, Kristian; Davila, Antonio; Recchia, Fabio A; Ballabh, Praveen; Pinto, John T; Ungvari, Zoltan

    2012-08-01

    The present study was conducted to test predictions of the oxidative stress theory of aging assessing reactive oxygen species production and oxidative stress resistance in cultured fibroblasts from 13 primate species ranging in body size from 0.25 to 120 kg and in longevity from 20 to 90 years. We assessed both basal and stress-induced reactive oxygen species production in fibroblasts from five great apes (human, chimpanzee, bonobo, gorilla, and orangutan), four Old World monkeys (baboon, rhesus and crested black macaques, and patas monkey), three New World monkeys (common marmoset, red-bellied tamarin, and woolly monkey), and one lemur (ring-tailed lemur). Measurements of cellular MitoSox fluorescence, an indicator of mitochondrial superoxide (O2(·-)) generation, showed an inverse correlation between longevity and steady state or metabolic stress-induced mitochondrial O2(·-) production, but this correlation was lost when the effects of body mass were removed, and the data were analyzed using phylogenetically independent contrasts. Fibroblasts from longer-lived primate species also exhibited superior resistance to H(2)O(2)-induced apoptotic cell death than cells from shorter-living primates. After correction for body mass and lack of phylogenetic independence, this correlation, although still discernible, fell short of significance by regression analysis. Thus, increased longevity in this sample of primates is not causally associated with low cellular reactive oxygen species generation, but further studies are warranted to test the association between increased cellular resistance to oxidative stressor and primate longevity. PMID:22219516

  4. Testing the Oxidative Stress Hypothesis of Aging in Primate Fibroblasts: Is There a Correlation Between Species Longevity and Cellular ROS Production?

    PubMed Central

    Csiszar, Anna; Podlutsky, Andrej; Podlutskaya, Natalia; Sonntag, William E.; Merlin, Steven Z.; Philipp, Eva E. R.; Doyle, Kristian; Davila, Antonio; Recchia, Fabio A.; Ballabh, Praveen; Pinto, John T.

    2012-01-01

    The present study was conducted to test predictions of the oxidative stress theory of aging assessing reactive oxygen species production and oxidative stress resistance in cultured fibroblasts from 13 primate species ranging in body size from 0.25 to 120 kg and in longevity from 20 to 90 years. We assessed both basal and stress-induced reactive oxygen species production in fibroblasts from five great apes (human, chimpanzee, bonobo, gorilla, and orangutan), four Old World monkeys (baboon, rhesus and crested black macaques, and patas monkey), three New World monkeys (common marmoset, red-bellied tamarin, and woolly monkey), and one lemur (ring-tailed lemur). Measurements of cellular MitoSox fluorescence, an indicator of mitochondrial superoxide (O2·−) generation, showed an inverse correlation between longevity and steady state or metabolic stress–induced mitochondrial O2·− production, but this correlation was lost when the effects of body mass were removed, and the data were analyzed using phylogenetically independent contrasts. Fibroblasts from longer-lived primate species also exhibited superior resistance to H2O2-induced apoptotic cell death than cells from shorter-living primates. After correction for body mass and lack of phylogenetic independence, this correlation, although still discernible, fell short of significance by regression analysis. Thus, increased longevity in this sample of primates is not causally associated with low cellular reactive oxygen species generation, but further studies are warranted to test the association between increased cellular resistance to oxidative stressor and primate longevity. PMID:22219516

  5. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS

    PubMed Central

    Gaude, Edoardo; Aksentijević, Dunja; Sundier, Stephanie Y.; Robb, Ellen L.; Logan, Angela; Nadtochiy, Sergiy M.; Ord, Emily N. J.; Smith, Anthony C.; Eyassu, Filmon; Shirley, Rachel; Hu, Chou-Hui; Dare, Anna J.; James, Andrew M.; Rogatti, Sebastian; Hartley, Richard C.; Eaton, Simon; Costa, Ana S.H.; Brookes, Paul S.; Davidson, Sean M.; Duchen, Michael R.; Saeb-Parsy, Kourosh; Shattock, Michael J.; Robinson, Alan J.; Work, Lorraine M.; Frezza, Christian; Krieg, Thomas; Murphy, Michael P.

    2014-01-01

    Ischaemia-reperfusion (IR) injury occurs when blood supply to an organ is disrupted and then restored, and underlies many disorders, notably heart attack and stroke. While reperfusion of ischaemic tissue is essential for survival, it also initiates oxidative damage, cell death, and aberrant immune responses through generation of mitochondrial reactive oxygen species (ROS)1-5. Although mitochondrial ROS production in IR is established, it has generally been considered a non-specific response to reperfusion1,3. Here, we developed a comparative in vivo metabolomic analysis and unexpectedly identified widely conserved metabolic pathways responsible for mitochondrial ROS production during IR. We showed that selective accumulation of the citric acid cycle (CAC) intermediate succinate is a universal metabolic signature of ischaemia in a range of tissues and is responsible for mitochondrial ROS production during reperfusion. Ischaemic succinate accumulation arises from reversal of succinate dehydrogenase (SDH), which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. Upon reperfusion, the accumulated succinate is rapidly re-oxidised by SDH, driving extensive ROS generation by reverse electron transport (RET) at mitochondrial complex I. Decreasing ischaemic succinate accumulation by pharmacological inhibition is sufficient to ameliorate in vivo IR injury in murine models of heart attack and stroke. Thus, we have identified a conserved metabolic response of tissues to ischaemia and reperfusion that unifies many hitherto unconnected aspects of IR injury. Furthermore, these findings reveal a novel pathway for metabolic control of ROS production in vivo, while demonstrating that inhibition of ischaemic succinate accumulation and its oxidation upon subsequent reperfusion is a potential therapeutic target to decrease IR injury in a range of pathologies. PMID:25383517

  6. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS.

    PubMed

    Chouchani, Edward T; Pell, Victoria R; Gaude, Edoardo; Aksentijević, Dunja; Sundier, Stephanie Y; Robb, Ellen L; Logan, Angela; Nadtochiy, Sergiy M; Ord, Emily N J; Smith, Anthony C; Eyassu, Filmon; Shirley, Rachel; Hu, Chou-Hui; Dare, Anna J; James, Andrew M; Rogatti, Sebastian; Hartley, Richard C; Eaton, Simon; Costa, Ana S H; Brookes, Paul S; Davidson, Sean M; Duchen, Michael R; Saeb-Parsy, Kourosh; Shattock, Michael J; Robinson, Alan J; Work, Lorraine M; Frezza, Christian; Krieg, Thomas; Murphy, Michael P

    2014-11-20

    Ischaemia-reperfusion injury occurs when the blood supply to an organ is disrupted and then restored, and underlies many disorders, notably heart attack and stroke. While reperfusion of ischaemic tissue is essential for survival, it also initiates oxidative damage, cell death and aberrant immune responses through the generation of mitochondrial reactive oxygen species (ROS). Although mitochondrial ROS production in ischaemia reperfusion is established, it has generally been considered a nonspecific response to reperfusion. Here we develop a comparative in vivo metabolomic analysis, and unexpectedly identify widely conserved metabolic pathways responsible for mitochondrial ROS production during ischaemia reperfusion. We show that selective accumulation of the citric acid cycle intermediate succinate is a universal metabolic signature of ischaemia in a range of tissues and is responsible for mitochondrial ROS production during reperfusion. Ischaemic succinate accumulation arises from reversal of succinate dehydrogenase, which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. After reperfusion, the accumulated succinate is rapidly re-oxidized by succinate dehydrogenase, driving extensive ROS generation by reverse electron transport at mitochondrial complex I. Decreasing ischaemic succinate accumulation by pharmacological inhibition is sufficient to ameliorate in vivo ischaemia-reperfusion injury in murine models of heart attack and stroke. Thus, we have identified a conserved metabolic response of tissues to ischaemia and reperfusion that unifies many hitherto unconnected aspects of ischaemia-reperfusion injury. Furthermore, these findings reveal a new pathway for metabolic control of ROS production in vivo, while demonstrating that inhibition of ischaemic succinate accumulation and its oxidation after subsequent reperfusion is a potential therapeutic target to decrease ischaemia

  7. Silica particles cause NADPH oxidase–independent ROS generation and transient phagolysosomal leakage

    PubMed Central

    Joshi, Gaurav N.; Goetjen, Alexandra M.; Knecht, David A.

    2015-01-01

    Chronic inhalation of silica particles causes lung fibrosis and silicosis. Silica taken up by alveolar macrophages causes phagolysosomal membrane damage and leakage of lysosomal material into the cytoplasm to initiate apoptosis. We investigated the role of reactive oxygen species (ROS) in this membrane damage by studying the spatiotemporal generation of ROS. In macrophages, ROS generated by NADPH oxidase 2 (NOX2) was detected in phagolysosomes containing either silica particles or nontoxic latex particles. ROS was only detected in the cytoplasm of cells treated with silica and appeared in parallel with an increase in phagosomal ROS, as well as several hours later associated with mitochondrial production of ROS late in apoptosis. Pharmacological inhibition of NOX activity did not prevent silica-induced phagolysosomal leakage but delayed it. In Cos7 cells, which do not express NOX2, ROS was detected in silica-containing phagolysosomes that leaked. ROS was not detected in phagolysosomes containing latex particles. Leakage of silica-containing phagolysosomes in both cell types was transient, and after resealing of the membrane, endolysosomal fusion continued. These results demonstrate that silica particles can generate phagosomal ROS independent of NOX activity, and we propose that this silica-generated ROS can cause phagolysosomal leakage to initiate apoptosis. PMID:26202463

  8. Soybean Salt Tolerance 1 (GmST1) Reduces ROS Production, Enhances ABA Sensitivity, and Abiotic Stress Tolerance in Arabidopsis thaliana.

    PubMed

    Ren, Shuxin; Lyle, Chimera; Jiang, Guo-Liang; Penumala, Abhishek

    2016-01-01

    Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative reverse transcription-polymerase chain reaction analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1 kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops. PMID:27148284

  9. Soybean Salt Tolerance 1 (GmST1) Reduces ROS Production, Enhances ABA Sensitivity, and Abiotic Stress Tolerance in Arabidopsis thaliana

    PubMed Central

    Ren, Shuxin; Lyle, Chimera; Jiang, Guo-liang; Penumala, Abhishek

    2016-01-01

    Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative reverse transcription-polymerase chain reaction analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1 kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops. PMID:27148284

  10. The ROS Wheel: Refining ROS Transcriptional Footprints1[OPEN

    PubMed Central

    Noctor, Graham

    2016-01-01

    In the last decade, microarray studies have delivered extensive inventories of transcriptome-wide changes in messenger RNA levels provoked by various types of oxidative stress in Arabidopsis (Arabidopsis thaliana). Previous cross-study comparisons indicated how different types of reactive oxygen species (ROS) and their subcellular accumulation sites are able to reshape the transcriptome in specific manners. However, these analyses often employed simplistic statistical frameworks that are not compatible with large-scale analyses. Here, we reanalyzed a total of 79 Affymetrix ATH1 microarray studies of redox homeostasis perturbation experiments. To create hierarchy in such a high number of transcriptomic data sets, all transcriptional profiles were clustered on the overlap extent of their differentially expressed transcripts. Subsequently, meta-analysis determined a single magnitude of differential expression across studies and identified common transcriptional footprints per cluster. The resulting transcriptional footprints revealed the regulation of various metabolic pathways and gene families. The RESPIRATORY BURST OXIDASE HOMOLOG F-mediated respiratory burst had a major impact and was a converging point among several studies. Conversely, the timing of the oxidative stress response was a determining factor in shaping different transcriptome footprints. Our study emphasizes the need to interpret transcriptomic data sets in a systematic context, where initial, specific stress triggers can converge to common, aspecific transcriptional changes. We believe that these refined transcriptional footprints provide a valuable resource for assessing the involvement of ROS in biological processes in plants. PMID:27246095

  11. Pre-exposure of neuroblastoma cell line to pulsed electromagnetic field prevents H2 O2 -induced ROS production by increasing MnSOD activity.

    PubMed

    Osera, Cecilia; Amadio, Marialaura; Falone, Stefano; Fassina, Lorenzo; Magenes, Giovanni; Amicarelli, Fernanda; Ricevuti, Giovanni; Govoni, Stefano; Pascale, Alessia

    2015-04-01

    Electromagnetic fields (EMFs) have been linked to increased risk of cancers and neurodegenerative diseases; however, EMFs can also elicit positive effects on biological systems, and redox status seems crucially involved in EMF biological effects. This study aimed to assess whether a short and repeated pulsed EMF (PEMF) could trigger adaptive responses against an oxidative insult in a neuronal cellular model. We found that a 40 min overall (four times a week, 10 min each) pre-exposure to PEMF did not affect major physiological parameters and led to a significant increase of Mn-dependent superoxide dismutase activity in the human neuroblastoma SH-SY5Y cell line. In addition, we found PEMF-pre-exposed cells exhibited decreased reactive oxygen species production following a 30 min H2 O2 challenge, with respect to non pre-exposed cells. Our findings might provide new insights on the role played by short and repeated PEMF stimulations in the enhancement of cellular defenses against oxidative insults. Although studies in normal neuronal cells would be useful to further confirm our hypothesis, we suggest that specific PEMF treatments may have potential biological repercussions in diseases where oxidative stress is implicated. PMID:25708841

  12. Evaluation of changes in lipid peroxidation, ROS production, surface structures, secondary metabolites and yield of linseed (Linum usitatissimum L.) under individual and combined stress of ultraviolet-B and ozone using open top chambers.

    PubMed

    Tripathi, Ruchika; Agrawal, S B

    2013-08-01

    The individual and interactive effects of supplemental UV-B (sUV-B) (ambient + 7.2 kJ m(-2) d(-1)) and elevated O3 (ambient + 10 ppb) were evaluated under field conditions using open top chambers on two cultivars, Padmini and T-397 of linseed (Linum usitatissimum L.). Mean monthly surface level of O3 concentrations varied from 27.7 ppb to 59.0 ppb during the experimental period. Both UV-B and O03 induced the production of ROS (H2O2 and O2*-), resulting in significant damage of membranes due to lipid peroxidation and electrolyte leakage. Synthesis of secondary metabolites (flavonoids, anthocyanin, lignin and wax) was also enhanced in all the treatments, whereas biomass and yield were reduced. Alterations in frequency of stomata and wax distribution were also observed through scanning electron microscopy (SEM). Cultivar Padmini was found to be more sensitive because of higher damage of membrane vis-a-vis reduction in biomass and seed yield. However, concentrations of flavonoids, anthocyanin, lignin and wax were higher in T-397, suggesting its relative resistance against applied stress. Combined exposure of sUV-B and O3 was less harmful, as compared to their individual treatment. Among the three treatments, O3 was found to be more detrimental for overall growth and sUV-B for economic yield. PMID:24772952

  13. Reactive oxygen species (ROS): involvement in bovine follicular cysts etiopathogenesis.

    PubMed

    Rizzo, Annalisa; Minoia, Giuseppe; Trisolini, Carmelinda; Mutinati, Maddalena; Spedicato, Massimo; Jirillo, Felicita; Sciorsci, Raffaele Luigi

    2009-01-01

    Ovulation is compared to an acute inflammatory process during which vasoactive agents, prostanoids, leukotrienes and Reactive Oxygen Species (ROS) develop. The aim of this study was to evaluate the levels of ROS in cystic and follicular fluid, in order to establish their involvement in the etiopathogenesis of Cystic Ovarian Follicle (COF) in dairy cows. The study was conducted in 30 healthy cows (group C) and 30 cows affected by COF (group COF). The fluid of follicular cysts and of preovulatory follicles was drawn by means of ultrasound guided aspiration from the cows of both groups. The fluid obtained was analyzed by a photometric analytical system to detect ROS level. ROS concentration was statistically lower in the cystic fluid than in the follicular one (62.4 +/- 13.36 U.Carr vs. 84.89 +/- 26.99 U.Carr) (p<0.05), thus suggesting that an alteration of the cascade responsible for ROS production may be implicated in the complex etipathogenesis of COF. PMID:19874233

  14. ROS and Phytohormones in Plant-Plant Allelopathic Interaction

    PubMed Central

    Gniazdowska, Agnieszka

    2007-01-01

    Allelopathy refers to plant-plant interference mediated mostly by plant released products of secondary metabolism. It was recently suggested that allelochamicals may influence growth of neighboring plants by induction of oxidative stress. We have focused on the role of reactive oxygen species (ROS) and phytohormons (ABA and ethylene) in the biochemical and molecular regulation of plant response to sunflower phytotoxins. PMID:19704634

  15. RAGE Expression and ROS Generation in Neurons: Differentiation versus Damage

    PubMed Central

    Piras, S.; Furfaro, A. L.; Domenicotti, C.; Traverso, N.; Marinari, U. M.; Pronzato, M. A.; Nitti, M.

    2016-01-01

    RAGE is a multiligand receptor able to bind advanced glycation end-products (AGEs), amphoterin, calgranulins, and amyloid-beta peptides, identified in many tissues and cells, including neurons. RAGE stimulation induces the generation of reactive oxygen species (ROS) mainly through the activity of NADPH oxidases. In neuronal cells, RAGE-induced ROS generation is able to favor cell survival and differentiation or to induce death through the imbalance of redox state. The dual nature of RAGE signaling in neurons depends not only on the intensity of RAGE activation but also on the ability of RAGE-bearing cells to adapt to ROS generation. In this review we highlight these aspects of RAGE signaling regulation in neuronal cells. PMID:27313835

  16. Cyanine fluorophores for cellular protection against ROS in stimulated macrophages and two-photon ROS detection.

    PubMed

    Chan, M S; Xu, D; Guo, L; Tam, D Y; Liu, L S; Chen, Y; Wong, M S; Lo, P K

    2015-07-14

    We report the first example of a novel two-photon active, biocompatible, and macrophage cell-membrane permeable carbazole-based cyanine fluorophore for the detection of three biologically important ROS, namely, ˙OH, O2(-) and OCl(-) in solution. This versatile probe shows cellular protection not only in stimulated macrophages from phorbol-12-myristate-13-acetate-induced morphological changes but also lipopolysaccharide-induced cytotoxicity by quenching with the O2(-) and OCl(-) production, respectively. Such protection could be visualized by a distinct change in the fluorescence intensity of the probe. PMID:26059852

  17. ROS1 fusions in cancer: a review.

    PubMed

    Uguen, Arnaud; De Braekeleer, Marc

    2016-08-01

    The ROS1 gene belongs to the sevenless subfamily of tyrosine kinase insulin receptor genes. A literature review identified a ROS1 fusion in 2.54% of the patients with lung adenocarcinoma and even higher frequencies in spitzoid neoplasms and inflammatory myofibroblastic tumors. At present, 26 genes were found to fuse with ROS1, some of them already known to fuse with RET and ALK. All the fusion proteins retain the ROS1 kinase domain, but rarely its transmembrane domain. Most of the partners have dimerization domains that are retained in the fusion, presumably leading to constitutive ROS1 tyrosine kinase activation. Some partners have transmembrane domains that are retained or not in the chimeric proteins. Therefore, different ROS1 fusions have distinct subcellular localization, suggesting that they may activate different substrates in vivo. PMID:27256160

  18. The regulatory roles of ethylene and reactive oxygen species (ROS) in plant salt stress responses.

    PubMed

    Zhang, Ming; Smith, J Andrew C; Harberd, Nicholas P; Jiang, Caifu

    2016-08-01

    Soil salinity is one of the most commonly encountered environmental stresses affecting plant growth and crop productivity. Accordingly, plants have evolved a variety of morphological, physiological and biochemical strategies that enable them to adapt to saline growth conditions. For example, it has long been known that salinity-stress increases both the production of the gaseous stress hormone ethylene and the in planta accumulation of reactive oxygen species (ROS). Recently, there has been significant progress in understanding how the fine-tuning of ethylene biosynthesis and signaling transduction can promote salinity tolerance, and how salinity-induced ROS accumulation also acts as a signal in the mediation of salinity tolerance. Furthermore, recent advances have indicated that ethylene signaling modulates salinity responses largely via regulation of ROS-generating and ROS-scavenging mechanisms. This review focuses on these recent advances in understanding the linked roles of ethylene and ROS in salt tolerance. PMID:27233644

  19. Immunohistochemical detection of ROS1 is useful for identifying ROS1 rearrangements in lung cancers.

    PubMed

    Yoshida, Akihiko; Tsuta, Koji; Wakai, Susumu; Arai, Yasuhito; Asamura, Hisao; Shibata, Tatsuhiro; Furuta, Koh; Kohno, Takashi; Kushima, Ryoji

    2014-05-01

    The recent discovery and characterization of an oncogenic ROS1 gene fusion in a subset of lung cancers has raised significant clinical interest because small molecule inhibitors may be effective to these tumors. As lung cancers with ROS1 rearrangements comprise only 1-3% of lung adenocarcinomas, patients with such tumors must be identified to gain optimal benefit from molecular therapy. Recently, immunohistochemical analyses using a novel anti-ROS1 rabbit monoclonal antibody (D4D6) have shown promise for accurate identification of ROS1-rearranged cancers. To validate this finding, we compared the immunostaining results of tissue microarrays (TMAs) containing 17 ROS1-rearranged and 253 ROS1-non-rearranged lung carcinomas. All 17 ROS1-rearranged cancers showed ROS1 immunoreactivity mostly in a diffuse and moderate-to-strong manner with an H-score range of 5-300 (median, 260). In contrast, 69% of ROS1-non-rearranged cancers lacked detectable immunoreactivity, whereas the remaining 31% showed reactivity mainly in a weak or focal manner. The H-score for the entire ROS1-non-rearranged group ranged from 0 to 240 (median, 0). The difference in H-score between the two cohorts was statistically significant, and the H-score cutoff (≥150) allowed optimal discrimination (94% sensitivity and 98% specificity). Similar but slightly less-specific performance was achieved using the extent of diffuse (≥75%) staining or ≥2+ staining intensity as cutoffs. CD74-ROS1 and EZR-ROS1 fusions were significantly associated with at least focal globular immunoreactivity and plasma membranous accentuation, respectively, and these patterns were specific to ROS1-rearranged cases. Although full-length ROS1 is expressed in some ROS1-non-rearranged cases, we showed that establishment of an optimal set of interpretative criteria makes ROS1 immunohistochemistry a valuable method to rapidly and accurately screen lung cancer patients for appropriate molecular therapy. PMID:24186139

  20. TNF-a stimulation enhances ROS-dependent cell migration via NF-?B activation in liver cells.

    PubMed

    Kastl, Lena; Sauer, Sven; Beissbarth, Tim; Becker, Michael; Krammer, Peter; Gülow, Karsten

    2014-10-01

    Development of hepatocellular carcinoma (HCC) is accompanied by a continuous increase in generation of reactive oxygen species (ROS). TNF-a was used in murine hepatocytes as stimulus to identify the primary source of ROS generation. Using specific inhibitors targeting the different complexes of the respiratory chain we detected the mitochondria as main producer of ROS. TNF-a altered mitochondrial integrity by mimicking a mild uncoupling effect in liver cells. siRNA mediated downregulation of essential assembly factors for complex I and complex III led to an inhibition of ROS production. Therefore, ROS is generated by the mitochondrial respiratory chain upon TNF-a stimulation. ROS activated NF-?B and subsequently enhanced migration of liver cells. Thus, we identified complex I and complex III of the respiratory chain as point of ROS release after TNF-a treatment in hepatocytes which enhances cell migration by activating NF-?B signaling. PMID:26461342

  1. ROS generation and multiple forms of mammalian mitochondrial glycerol-3-phosphate dehydrogenase.

    PubMed

    Mráček, Tomáš; Holzerová, Eliška; Drahota, Zdeněk; Kovářová, Nikola; Vrbacký, Marek; Ješina, Pavel; Houštěk, Josef

    2014-01-01

    Overproduction of reactive oxygen species (ROS) has been implicated in a range of pathologies. Mitochondrial flavin dehydrogenases glycerol-3-phosphate dehydrogenase (mGPDH) and succinate dehydrogenase (SDH) represent important ROS source, but the mechanism of electron leak is still poorly understood. To investigate the ROS production by the isolated dehydrogenases, we used brown adipose tissue mitochondria solubilized by digitonin as a model. Enzyme activity measurements and hydrogen peroxide production studies by Amplex Red fluorescence, and luminol luminescence in combination with oxygraphy revealed flavin as the most likely source of electron leak in SDH under in vivo conditions, while we propose coenzyme Q as the site of ROS production in the case of mGPDH. Distinct mechanism of ROS production by the two dehydrogenases is also apparent from induction of ROS generation by ferricyanide which is unique for mGPDH. Furthermore, using native electrophoretic systems, we demonstrated that mGPDH associates into homooligomers as well as high molecular weight supercomplexes, which represent native forms of mGPDH in the membrane. By this approach, we also directly demonstrated that isolated mGPDH itself as well as its supramolecular assemblies are all capable of ROS production. PMID:23999537

  2. Mechanical Stretch-Induced Activation of ROS/RNS Signaling in Striated Muscle

    PubMed Central

    Ward, Christopher W.; Prosser, Benjamin L.

    2014-01-01

    Significance: Mechanical activation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) occurs in striated muscle and affects Ca2+ signaling and contractile function. ROS/RNS signaling is tightly controlled, spatially compartmentalized, and source specific. Recent Advances: Here, we review the evidence that within the contracting myocyte, the trans-membrane protein NADPH oxidase 2 (Nox2) is the primary source of ROS generated during contraction. We also review a newly characterized signaling cascade in cardiac and skeletal muscle in which the microtubule network acts as a mechanotransduction element that activates Nox2-dependent ROS generation during mechanical stretch, a pathway termed X-ROS signaling. Critical Issues: In the heart, X-ROS acts locally and affects the sarcoplasmic reticulum (SR) Ca2+ release channels (ryanodine receptors) and tunes Ca2+ signaling during physiological behavior, but excessive X-ROS can promote Ca2+-dependent arrhythmias in pathology. In skeletal muscle, X-ROS sensitizes Ca2+-permeable sarcolemmal “transient receptor potential” channels, a pathway that is critical for sustaining SR load during repetitive contractions, but when in excess, it is maladaptive in diseases such as Duchenne Musclar dystrophy. Future Directions: New advances in ROS/RNS detection as well as molecular manipulation of signaling pathways will provide critical new mechanistic insights into the details of X-ROS signaling. These efforts will undoubtedly reveal new avenues for therapeutic intervention in the numerous diseases of striated muscle in which altered mechanoactivation of ROS/RNS production has been identified. Antioxid. Redox Signal. 20, 929–936. PMID:23971496

  3. Reactive Oxygen Species (ROS) generation by lunar simulants

    NASA Astrophysics Data System (ADS)

    Kaur, Jasmeet; Rickman, Douglas; Schoonen, Martin A.

    2016-05-01

    .5 h. By contrast ROS is formed rapidly within 30 min when simulants are dispersed in DI, but then the concentration either stabilizes or decreases over time. The results indicate that mechanical stress and the absence of molecular oxygen and water, which are important environmental characteristics of the lunar environment, can lead to enhanced production of ROS in general. However, compositional difference among simulants is the most important factor in governing the production of ROS. Simulants with glass content in excess of 40 wt% appear to produce as much as of order of magnitude more ROS than simulants with lower glass content.

  4. ROS-talk - how the apoplast, the chloroplast, and the nucleus get the message through.

    PubMed

    Shapiguzov, Alexey; Vainonen, Julia P; Wrzaczek, Michael; Kangasjärvi, Jaakko

    2012-01-01

    The production of reactive oxygen species (ROS) in different plant subcellular compartments is the hallmark of the response to many stress stimuli and developmental cues. The past two decades have seen a transition from regarding ROS as exclusively cytotoxic agents to being considered as reactive compounds which participate in elaborate signaling networks connecting various aspects of plant life. We have now arrived at a stage where it has become increasingly difficult to disregard the communication between different types and pools of ROS. Production of ROS in the extracellular space, the apoplast, can influence their generation in the chloroplast and both can regulate nuclear gene expression. In spite of existing information on these signaling events, we can still barely grasp the mechanisms of ROS signaling and communication between the organelles. In this review, we summarize evidence that supports the mutual influence of extracellular and chloroplastic ROS production on nuclear gene regulation and how this interaction might occur. We also reflect on how, and via which routes signals might reach the nucleus where they are ultimately integrated for transcriptional reprogramming. New ideas and approaches will be needed in the future to address the pressing questions of how ROS as signaling molecules can participate in the coordination of stress adaptation and development and how they are involved in the chatter of the organelles. PMID:23293644

  5. Lysosome-controlled efficient ROS overproduction against cancer cells with a high pH-responsive catalytic nanosystem

    NASA Astrophysics Data System (ADS)

    Fu, Jingke; Shao, Yiran; Wang, Liyao; Zhu, Yingchun

    2015-04-01

    Excess reactive oxygen species (ROS) have been proved to damage cancer cells efficiently. ROS overproduction is thus greatly desirable for cancer therapy. To date, ROS production is generally uncontrollable and outside cells, which always bring severe side-effects in the vasculature. Since most ROS share a very short half-life and primarily react close to their site of formation, it would be more efficient if excess ROS are controllably produced inside cancer cells. Herein, we report an efficient lysosome-controlled ROS overproduction via a pH-responsive catalytic nanosystem (FeOx-MSNs), which catalyze the decomposition of H2O2 to produce considerable ROS selectively inside the acidic lysosomes (pH 5.0) of cancer cells. After a further incorporation of ROS-sensitive TMB into the nanosystem (FeOx-MSNs-TMB), both a distinct cell labeling and an efficient death of breast carcinoma cells are obtained. This lysosome-controlled efficient ROS overproduction suggests promising applications in cancer treatments.Excess reactive oxygen species (ROS) have been proved to damage cancer cells efficiently. ROS overproduction is thus greatly desirable for cancer therapy. To date, ROS production is generally uncontrollable and outside cells, which always bring severe side-effects in the vasculature. Since most ROS share a very short half-life and primarily react close to their site of formation, it would be more efficient if excess ROS are controllably produced inside cancer cells. Herein, we report an efficient lysosome-controlled ROS overproduction via a pH-responsive catalytic nanosystem (FeOx-MSNs), which catalyze the decomposition of H2O2 to produce considerable ROS selectively inside the acidic lysosomes (pH 5.0) of cancer cells. After a further incorporation of ROS-sensitive TMB into the nanosystem (FeOx-MSNs-TMB), both a distinct cell labeling and an efficient death of breast carcinoma cells are obtained. This lysosome-controlled efficient ROS overproduction suggests

  6. TRAP-positive osteoclast precursors mediate ROS/NO-dependent bactericidal activity via TLR4.

    PubMed

    Nishimura, Kazuaki; Shindo, Satoru; Movila, Alexandru; Kayal, Rayyan; Abdullah, Albassam; Savitri, Irma Josefina; Ikeda, Atsushi; Yamaguchi, Tsuguno; Howait, Mohammed; Al-Dharrab, Ayman; Mira, Abdulghani; Han, Xiaozhe; Kawai, Toshihisa

    2016-08-01

    Osteoclastogenesis was induced by RANKL stimulation in mouse monocytes to examine the possible bactericidal function of osteoclast precursors (OCp) and mature osteoclasts (OCm) relative to their production of NO and ROS. Tartrate-resistant acid phosphatase (TRAP)-positive OCp, but few or no OCm, phagocytized and killed Escherichia coli in association with the production of reactive oxygen species (ROS) and nitric oxide (NO). Phagocytosis of E. coli and production of ROS and NO were significantly lower in TRAP+ OCp derived from Toll-like receptor (TLR)-4 KO mice than that derived from wild-type (WT) or TLR2-KO mice. Interestingly, after phagocytosis, TRAP+ OCp derived from wild-type and TLR2-KO mice did not differentiate into OCm, even with continuous exposure to RANKL. In contrast, E. coli-phagocytized TRAP+ OCp from TLR4-KO mice could differentiate into OCm. Importantly, neither NO nor ROS produced by TRAP+ OCp appeared to be engaged in phagocytosis-induced suppression of osteoclastogenesis. These results suggested that TLR4 signaling not only induces ROS and NO production to kill phagocytized bacteria, but also interrupts OCm differentiation. Thus, it can be concluded that TRAP+ OCp, but not OCm, can mediate bactericidal activity via phagocytosis accompanied by the production of ROS and NO via TLR4-associated reprograming toward phagocytic cell type. PMID:27343691

  7. Surface functionalization of titanium dioxide nanoparticles: Photo-stability and reactive oxygen species (ROS) generation

    NASA Astrophysics Data System (ADS)

    Louis, Kacie M.

    Metal oxide nanoparticles are becoming increasingly prevalent in society for applications of sunscreens, cosmetics, paints, biomedical imaging, and photovoltaics. Due to the increased surface area to volume ratio of nanoparticles compared to bulk materials, it is important to know the health and safety impacts of these materials. One mechanism of toxicity of nominally "safe" materials such as TiO 2 is through the photocatalytic generation of reactive oxygen species (ROS). ROS production and ligand degradation can affect the bioavailability of these particles in aqueous organisms. We have investigated ROS generation by functionalized TiO2 nanoparticles and its influence on aggregation and bioavailability and toxicity to zebrafish embryos/larvae. For these studies we investigated anatase TiO2 nanoparticles. For application purposes and solution stability, the TiO2 nanoparticles were functionalized with a variety of ligands such as citrate, 3,4-dihydroxybenzaldehyde, and ascorbate. We quantitatively examined the amount of ROS produced in aqueous solution using fluorescent probes and see that more ROS is produced under UV light than in the dark control. Our measurements show that TiO2 toxicity reaches a maximum for nanoparticles with smaller diameters, and is correlated with surface area dependent changes in ROS generation. In an effort to reduce toxicity through control of the surface and surface ligands, we synthesized anatase nanoparticles of different sizes, functionalized them with different ligands, and examined the resulting ROS generation and ligand stability. Using a modular ligand containing a hydrophobic inner region and a hydrophilic outer region, we synthesized water-stable nanoparticles, via two different chemical reactions, having much-reduced ROS generation and thus reduced toxicity. These results suggest new strategies for making safer nanoparticles while still retaining their desired properties. We also examine the degradation of the different ligands

  8. Redox-optimized ROS balance and the relationship between mitochondrial respiration and ROS.

    PubMed

    Cortassa, Sonia; O'Rourke, Brian; Aon, Miguel A

    2014-02-01

    The Redox-Optimized ROS Balance [R-ORB] hypothesis postulates that the redox environment [RE] is the main intermediary between mitochondrial respiration and reactive oxygen species [ROS]. According to R-ORB, ROS emission levels will attain a minimum vs. RE when respiratory rate (VO2) reaches a maximum following ADP stimulation, a tenet that we test herein in isolated heart mitochondria under forward electron transport [FET]. ROS emission increased two-fold as a function of changes in the RE (~400 to ~900mV·mM) in state 4 respiration elicited by increasing glutamate/malate (G/M). In G/M energized mitochondria, ROS emission decreases two-fold for RE ~500 to ~300mV·mM in state 3 respiration at increasing ADP. Stressed mitochondria released higher ROS, that was only weakly dependent on RE under state 3. As a function of VO2, the ROS dependence on RE was strong between ~550 and ~350mV·mM, when VO2 is maximal, primarily due to changes in glutathione redox potential. A similar dependence was observed with stressed mitochondria, but over a significantly more oxidized RE and ~3-fold higher ROS emission overall, as compared with non-stressed controls. We conclude that under non-stressful conditions mitochondrial ROS efflux decreases when the RE becomes less reduced within a range in which VO2 is maximal. These results agree with the R-ORB postulate that mitochondria minimize ROS emission as they maximize VO2 and ATP synthesis. This relationship is altered quantitatively, but not qualitatively, by oxidative stress although stressed mitochondria exhibit diminished energetic performance and increased ROS release. PMID:24269780

  9. Endogenous Cytokinin Overproduction Modulates ROS Homeostasis and Decreases Salt Stress Resistance in Arabidopsis Thaliana

    PubMed Central

    Wang, Yanping; Shen, Wenzhong; Chan, Zhulong; Wu, Yan

    2015-01-01

    Cytokinins in plants are crucial for numerous biological processes, including seed germination, cell division and differentiation, floral initiation and adaptation to abiotic stresses. The salt stress can promote reactive oxygen species (ROS) production in plants which are highly toxic and ultimately results in oxidative stress. However, the correlation between endogenous cytokinin production and ROS homeostasis in responding to salt stress is poorly understood. In this study, we analyzed the correlation of overexpressing the cytokinin biosynthetic gene AtIPT8 (adenosine phosphate-isopentenyl transferase 8) and the response of salt stress in Arabidopsis. Overproduction of cytokinins, which was resulted by the inducible overexpression of AtIPT8, significantly inhibited the primary root growth and true leaf emergence, especially under the conditions of exogenous salt, glucose and mannitol treatments. Upon cytokinin overproduction, the salt stress resistance was declined, and resulted in less survival rates and chlorophyll content. Interestingly, ROS production was obviously increased with the salt treatment, accompanied by endogenously overproduced cytokinins. The activities of catalase (CAT) and superoxide dismutase (SOD), which are responsible for scavenging ROS, were also affected. Transcription profiling revealed that the differential expressions of ROS-producing and scavenging related genes, the photosynthesis-related genes and stress responsive genes were existed in transgenic plants of overproducing cytokinins. Our results suggested that broken in the homeostasis of cytokinins in plant cells could modulate the salt stress responses through a ROS-mediated regulation in Arabidopsis. PMID:26635831

  10. Endogenous Cytokinin Overproduction Modulates ROS Homeostasis and Decreases Salt Stress Resistance in Arabidopsis Thaliana.

    PubMed

    Wang, Yanping; Shen, Wenzhong; Chan, Zhulong; Wu, Yan

    2015-01-01

    Cytokinins in plants are crucial for numerous biological processes, including seed germination, cell division and differentiation, floral initiation and adaptation to abiotic stresses. The salt stress can promote reactive oxygen species (ROS) production in plants which are highly toxic and ultimately results in oxidative stress. However, the correlation between endogenous cytokinin production and ROS homeostasis in responding to salt stress is poorly understood. In this study, we analyzed the correlation of overexpressing the cytokinin biosynthetic gene AtIPT8 (adenosine phosphate-isopentenyl transferase 8) and the response of salt stress in Arabidopsis. Overproduction of cytokinins, which was resulted by the inducible overexpression of AtIPT8, significantly inhibited the primary root growth and true leaf emergence, especially under the conditions of exogenous salt, glucose and mannitol treatments. Upon cytokinin overproduction, the salt stress resistance was declined, and resulted in less survival rates and chlorophyll content. Interestingly, ROS production was obviously increased with the salt treatment, accompanied by endogenously overproduced cytokinins. The activities of catalase (CAT) and superoxide dismutase (SOD), which are responsible for scavenging ROS, were also affected. Transcription profiling revealed that the differential expressions of ROS-producing and scavenging related genes, the photosynthesis-related genes and stress responsive genes were existed in transgenic plants of overproducing cytokinins. Our results suggested that broken in the homeostasis of cytokinins in plant cells could modulate the salt stress responses through a ROS-mediated regulation in Arabidopsis. PMID:26635831

  11. Targeting CSCs in Tumor Microenvironment: The Potential Role of ROS-Associated miRNAs in Tumor Aggressiveness

    PubMed Central

    Bao, Bin; Azmi, Asfar S.; Li, Yiwei; Ahmad, Aamir; Ali, Shadan; Banerjee, Sanjeev; Kong, Dejuan; Sarkar, Fazlul H.

    2015-01-01

    Reactive oxygen species (ROS) have been widely considered as critical cellular signaling molecules involving in various biological processes such as cell growth, differentiation, proliferation, apoptosis, and angiogenesis. The homeostasis of ROS is critical to maintain normal biological processes. Increased production of ROS, namely oxidative stress, due to either endogenous or exogenous sources causes irreversible damage of bio-molecules such as DNA, proteins, lipids, and sugars, leading to genomic instability, genetic mutation, and altered gene expression, eventually contributing to tumorigenesis. A great amount of experimental studies in vitro and in vivo have produced solid evidence supporting that oxidative stress is strongly associated with increased tumor cell growth, treatment resistance, and metastasis, and all of which contribute to tumor aggressiveness. More recently, the data have indicated that altered production of ROS is also associated with cancer stem cells (CSCs), epithelial-to-mesenchymal transition (EMT), and hypoxia, the most common features or phenomena in tumorigenesis and tumor progression. However, the exact mechanism by which ROS is involved in the regulation of CSC and EMT characteristics as well as hypoxia- and, especially, HIF-mediated pathways is not well known. Emerging evidence suggests the role of miRNAs in tumorigenesis and progression of human tumors. Recently, the data have indicated that altered productions of ROS are associated with deregulated expression of miRNAs, suggesting their potential roles in the regulation of ROS production. Therefore, targeting ROS mediated through the deregulation of miRNAs by novel approaches or by naturally occurring anti-oxidant agents such as genistein could provide a new therapeutic approach for the prevention and/or treatment of human malignancies. In this article, we will discuss the potential role of miRNAs in the regulation of ROS production during tumorigenesis. Finally, we will discuss

  12. Endoplasmic Reticulum Stress and Associated ROS

    PubMed Central

    Zeeshan, Hafiz Maher Ali; Lee, Geum Hwa; Kim, Hyung-Ryong; Chae, Han-Jung

    2016-01-01

    The endoplasmic reticulum (ER) is a fascinating network of tubules through which secretory and transmembrane proteins enter unfolded and exit as either folded or misfolded proteins, after which they are directed either toward other organelles or to degradation, respectively. The ER redox environment dictates the fate of entering proteins, and the level of redox signaling mediators modulates the level of reactive oxygen species (ROS). Accumulating evidence suggests the interrelation of ER stress and ROS with redox signaling mediators such as protein disulfide isomerase (PDI)-endoplasmic reticulum oxidoreductin (ERO)-1, glutathione (GSH)/glutathione disuphide (GSSG), NADPH oxidase 4 (Nox4), NADPH-P450 reductase (NPR), and calcium. Here, we reviewed persistent ER stress and protein misfolding-initiated ROS cascades and their significant roles in the pathogenesis of multiple human disorders, including neurodegenerative diseases, diabetes mellitus, atherosclerosis, inflammation, ischemia, and kidney and liver diseases. PMID:26950115

  13. Potential chemoprevention of LPS-stimulated nitric oxide and prostaglandin E₂ production by α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-3-indolecarbonate in BV2 microglial cells through suppression of the ROS/PI3K/Akt/NF-κB pathway.

    PubMed

    Dilshara, Matharage Gayani; Lee, Kyoung-Tae; Choi, Yung Hyun; Moon, Dong-Oh; Lee, Hak-Ju; Yun, Sung Gyu; Kim, Gi-Young

    2014-02-01

    α-l-Rhamnopyranosyl-(1→6)-β-d-glucopyranosyl-3-indolecarbonate (RG3I) is a chemical constituent isolated from the commonly used Asian traditional medicinal plant, Clematis mandshurica; however, no studies have been reported on its anti-inflammatory properties. In the present study, we found that RG3I attenuates the lipopolysaccharide (LPS)-induced DNA-binding activity of nuclear factor-κB (NF-κB) via the dephosphorylation of PI3K/Akt in BV2 microglial cells, leading to a suppression of nitric oxide (NO) and prostaglandin E2 (PGE2) production, along with that of their regulatory genes, inducible NO synthase (iNOS) and cyclooxygenase-2 (Cox-2). Further, the PI3K/Akt inhibitor, LY294002 diminished the expression of LPS-stimulated iNOS and COX-2 genes by suppressing NF-κB activity. Moreover, RG3I significantly inhibited LPS-induced reactive oxygen species (ROS) generation similar to the ROS inhibitors, N-acetylcysteine (NAC) and glutathione (GSH). Notably, NAC and GSH abolished the LPS-induced expression of iNOS and Cox-2 in BV2 microglial cells by inhibiting NF-κB activity. Taken together, our data indicate that RG3I suppresses the production of proinflammatory mediators such as NO and PGE2 as well as their regulatory genes in LPS-stimulated BV2 microglial cells by inhibiting the PI3K/Akt- and ROS-dependent NF-κB signaling pathway, suggesting that RG3I may be a good candidate to regulate LPS-induced inflammatory response. PMID:24486459

  14. Lysosome-controlled efficient ROS overproduction against cancer cells with a high pH-responsive catalytic nanosystem.

    PubMed

    Fu, Jingke; Shao, Yiran; Wang, Liyao; Zhu, Yingchun

    2015-04-28

    Excess reactive oxygen species (ROS) have been proved to damage cancer cells efficiently. ROS overproduction is thus greatly desirable for cancer therapy. To date, ROS production is generally uncontrollable and outside cells, which always bring severe side-effects in the vasculature. Since most ROS share a very short half-life and primarily react close to their site of formation, it would be more efficient if excess ROS are controllably produced inside cancer cells. Herein, we report an efficient lysosome-controlled ROS overproduction via a pH-responsive catalytic nanosystem (FeOx-MSNs), which catalyze the decomposition of H2O2 to produce considerable ROS selectively inside the acidic lysosomes (pH 5.0) of cancer cells. After a further incorporation of ROS-sensitive TMB into the nanosystem (FeOx-MSNs-TMB), both a distinct cell labeling and an efficient death of breast carcinoma cells are obtained. This lysosome-controlled efficient ROS overproduction suggests promising applications in cancer treatments. PMID:25813671

  15. Mitochondrial ROS Metabolism: 10 Years Later

    PubMed Central

    Kushnareva, Y. E.; Murphy, A. N.

    2015-01-01

    The role of mitochondria in oxidative stress is well recognized, but many questions are still to be answered. This article is intended to update our comprehensive review in 2005 by highlighting the progress in understanding of mitochondrial reactive oxygen species (ROS) metabolism over the past 10 years. We review the recently identified or re-appraised sources of ROS generation in mitochondria, such as p66shc protein, succinate dehydrogenase, and recently discovered properties of the mitochondrial antioxidant system. We also reflect upon some controversies, disputes, and misconceptions that confound the field. PMID:26071769

  16. Mitochondrial ROS fire up T cell activation.

    PubMed

    Murphy, Michael P; Siegel, Richard M

    2013-02-21

    Metabolic reprogramming has emerged as an important feature of immune cell activation. Two new studies, including Sena et al. (2013) in this issue of Immunity, identify mitochondrial reactive oxygen species (ROS) arising from metabolic reprogramming as signaling molecules in T cell activation. PMID:23438817

  17. Reactive oxygen species (ROS) mediates non-freezing cold injury of rat sciatic nerve

    PubMed Central

    Geng, Zhiwei; Tong, Xiaoyan; Jia, Hongjuan

    2015-01-01

    Non-freezing cold injury is an injury characterized by neuropathy, developing when patients expose to cold environments. Reactive oxygen species (ROS) has been shown as a contributing factor for the non-freezing cold nerve injury. However, the detailed connections between non-freezing cold nerve injury and ROS have not been described. In order to investigate the relationship between non-freezing cold nerve injury and reactive oxygen species, we study the effects of two cooling methods-the continuous cooling and the intermittent cooling with warming intervals-on rat sciatic nerves. Specifically, we assess the morphological changes and ROS production of the sciatic nerves underwent different cooling treatments. Our data shows both types of cooling methods cause nerve injury and ROS production. However, despite of identical cooling degree and duration, the sciatic nerves processed by intermittent cooling with warming intervals present more ROS production, severer reperfusion injury and pathological destructions than the sciatic nerves processed by continuous cooling. This result indicates reactive oxygen species, as a product of reperfusion, facilitates non-freezing cold nerve injury. PMID:26629065

  18. Deficient autophagy unravels the ROS paradox in chronic granulomatous disease.

    PubMed

    van de Veerdonk, Frank L; Dinarello, Charles A

    2014-06-01

    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 1β 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

  19. Akt mediated ROS-dependent selective targeting of mutant KRAS tumors.

    PubMed

    Iskandar, Kartini; Rezlan, Majidah; Pervaiz, Shazib

    2014-10-01

    Reactive oxygen species (ROS) play a critical role in a variety of cellular processes, ranging from cell survival and proliferation to cell death. Previously, we reported the ability of a small molecule compound, C1, to induce ROS dependent autophagy associated apoptosis in human cancer cell lines and primary tumor cells (Wong C. et al. 2010). Our ongoing investigations have unraveled a hitherto undefined novel signaling network involving hyper-phosphorylation of Akt and Akt-mediated ROS production in cancer cell lines. Interestingly, drug-induced Akt activation is selectively seen in cell lines that carry mutant KRAS; HCT116 cells that carry the V13D KRAS mutation respond favorably to C1 while HT29 cells expressing wild type KRAS are relatively resistant. Of note, not only does the compound target mutant KRAS expressing cells but also induces RAS activation as evidenced by the PAK pull down assay. Corroborating this, pharmacological inhibition as well as siRNA mediated silencing of KRAS or Akt, blocked C1-induced ROS production and rescued tumor colony forming ability in HCT116 cells. To further confirm the involvement of KRAS, we made use of mutant KRAS transformed RWPE-1 prostate epithelial cells. Notably, drug-induced ROS generation and death sensitivity was significantly higher in RWPE-1-KRAS cells than the RWPE-1-vector cells, thus confirming the results obtained with mutant KRAS colorectal carcinoma cell line. Lastly, we made use of HCT116 mutant KRAS knockout cells (KO) where the mutant KRAS allele had been deleted, thus expressing a single wild-type KRAS allele. Exposure of the KO cells to C1 failed to induce Akt activation and mitochondrial ROS production. Taken together, results show the involvement of activated Akt in ROS-mediated selective targeting of mutant KRAS expressing tumors, which could have therapeutic implications given the paucity of chemotherapeutic strategies specifically targeting KRAS mutant cancers. PMID:26461287

  20. ROS Mediated Stress Response in Illuminated Cattle Feces Derived DOM

    EPA Science Inventory

    Bacterial exposure to exogenous reactive oxygen species (ROS) is known to increase theexpression of oxidative stress related genes and has been linked to acquisition of antibioticresistance (AR). ROS, including hydrogen peroxide (H202), singlet oxygen e o 2), andhydroxyl radicals...

  1. ROS-dependent phosphorylation of Bax by wortmannin sensitizes melanoma cells for TRAIL-induced apoptosis

    PubMed Central

    Quast, S-A; Berger, A; Eberle, J

    2013-01-01

    The pathways of reactive oxygen species (ROS)-mediated apoptosis induction, of Bax activation and the sensitization of tumor cells for TRAIL (TNF-related apoptosis-inducing ligand)-induced apoptosis are still largely elusive. Here, sensitization of melanoma cells for TRAIL by the PI3-kinase inhibitor wortmannin correlated to the activation of mitochondrial apoptosis pathways. Apoptosis was dependent on Bax and abrogated by Bcl-2 overexpression. The synergistic enhancement was explained by Bax activation through wortmannin, which tightly correlated to the characteristic Bax phosphorylation patterns. Thus, wortmannin resulted in early reduction of the Bax-inactivating phosphorylation at serine-184, whereas the Bax-activating phosphorylation at threonine-167 was enhanced. Proving the responsibility of the pathway, comparable effects were obtained with an Akt inhibitor (MK-2206); while suppressed phosphorylation of serine-184 may be attributed to reduced Akt activity itself, the causes of enhanced threonine-167 phosphorylation were addressed here. Characteristically, production of ROS was seen early in response to wortmannin and MK-2206. Providing the link between ROS and Bax, we show that abrogated ROS production by α-tocopherol or by NADPH oxidase 4 (NOX4) siRNA suppressed apoptosis and Bax activation. This correlated with reduced Bax phosphorylation at threonine-167. The data unraveled a mechanism by which NOX4-dependent ROS production controls apoptosis via Bax phosphorylation. The pathway may be considered for proapoptotic, anticancer strategies. PMID:24113173

  2. Exercise-induced ROS in heat shock proteins response.

    PubMed

    Dimauro, Ivan; Mercatelli, Neri; Caporossi, Daniela

    2016-09-01

    Cells have evolved multiple and sophisticated stress response mechanisms aiming to prevent macromolecular (including proteins, lipids, and nucleic acids) damage and to maintain or re-establish cellular homeostasis. Heat shock proteins (HSPs) are among the most highly conserved, ubiquitous, and abundant proteins in all organisms. Originally discovered more than 50 years ago through heat shock stress, they display multiple, remarkable roles inside and outside cells under a variety of stresses, including also oxidative stress and radiation, recognizing unfolded or misfolded proteins and facilitating their restructuring. Exercise consists in a combination of physiological stresses, such as metabolic disturbances, changes in circulating levels of hormones, increased temperature, induction of mild to severe inflammatory state, increased production of reactive oxygen and nitrogen species (ROS and RNS). As a consequence, exercise is one of the main stimuli associated with a robust increase in different HSPs in several tissues, which appears to be also fundamental in facilitating the cellular remodeling processes related to the training regime. Among all factors involved in the exercise-related modulation of HSPs level, the ROS production in the contracting muscle or in other tissues represents one of the most attracting, but still under discussion, mechanism. Following exhaustive or damaging muscle exercise, major oxidative damage to proteins and lipids is likely involved in HSP expression, together with mechanically induced damage to muscle proteins and the inflammatory response occurring several days into the recovery period. Instead, the transient and reversible oxidation of proteins by physiological concentrations of ROS seems to be involved in the activation of stress response following non-damaging muscle exercise. This review aims to provide a critical update on the role of HSPs response in exercise-induced adaptation or damage in humans, focusing on experimental

  3. ROS signaling during granzyme B-mediated apoptosis

    PubMed Central

    Martinvalet, Denis

    2015-01-01

    Reactive oxygen species (ROS) are involved in cell signaling, aging, and death and play a role in carcinogenesis. However, whether ROS are bystanders or active effectors of apoptosis was unclear until recently. New evidence shows that the killer lymphocyte protease granzyme B activates a conserved biochemical pathway centered on respiratory chain disruption to trigger mitocentric ROS-dependent apoptosis. PMID:27308474

  4. Calcium and ROS: A mutual interplay

    PubMed Central

    Görlach, Agnes; Bertram, Katharina; Hudecova, Sona; Krizanova, Olga

    2015-01-01

    Calcium is an important second messenger involved in intra- and extracellular signaling cascades and plays an essential role in cell life and death decisions. The Ca2+ signaling network works in many different ways to regulate cellular processes that function over a wide dynamic range due to the action of buffers, pumps and exchangers on the plasma membrane as well as in internal stores. Calcium signaling pathways interact with other cellular signaling systems such as reactive oxygen species (ROS). Although initially considered to be potentially detrimental byproducts of aerobic metabolism, it is now clear that ROS generated in sub-toxic levels by different intracellular systems act as signaling molecules involved in various cellular processes including growth and cell death. Increasing evidence suggests a mutual interplay between calcium and ROS signaling systems which seems to have important implications for fine tuning cellular signaling networks. However, dysfunction in either of the systems might affect the other system thus potentiating harmful effects which might contribute to the pathogenesis of various disorders. PMID:26296072

  5. The kinases Mst1 and Mst2 positively regulate phagocyte ROS induction and bactericidal activity

    PubMed Central

    Geng, Jing; Sun, Xiufeng; Wang, Ping; Zhang, Shihao; Wang, Xiaozhen; Wu, Hongtan; Hong, Lixin; Xie, Changchuan; Li, Xun; Zhao, Hao; Liu, Qingxu; Jiang, Mingting; Chen, Qinghua; Zhang, Jinjia; Li, Yang; Song, Siyang; Wang, Hong-Rui; Zhou, Rongbin; Johnson, Randy L.; Chien, Kun-Yi; Lin, Sheng-Cai; Han, Jiahuai; Avruch, Joseph; Chen, Lanfen; Zhou, Dawang

    2015-01-01

    Summary Mitochondria need to be juxtaposted to phagosomes to synergistically produce ample reactive oxygen species (ROS) in phagocytes for pathogens killing. However, how phagosomes transmit signal to recruit mitochondria remains unclear. Here, we report that the kinases Mst1 and Mst2 function to control ROS production by regulating mitochondrial trafficking and mitochondrion-phagosome juxtaposition. Mst1 and Mst2 activate Rac GTPase to promote Toll-like receptor (TLR)-triggered assembly of the TRAF6-ECSIT complex that is required for mitochondrial recruitment to phagosomes. Inactive forms of Rac, including the human Rac2D57N mutant, disrupt the TRAF6-ECSIT complex by sequestering TRAF6, and severely dampen ROS production and greatly increase susceptibility to bacterial infection. These findings demonstrate the TLR-Mst1-Mst2-Rac signalling axis to be critical for effective phagosome-mitochondrion function and bactericidal activity. PMID:26414765

  6. Inhibition of SH2-domain-containing inositol 5-phosphatase (SHIP2) ameliorates palmitate induced-apoptosis through regulating Akt/FOXO1 pathway and ROS production in HepG2 cells

    SciTech Connect

    Gorgani-Firuzjaee, Sattar; Adeli, Khosrow; Meshkani, Reza

    2015-08-21

    The serine–threonine kinase Akt regulates proliferation and survival by phosphorylating a network of protein substrates; however, the role of a negative regulator of the Akt pathway, the SH2-domain-containing inositol 5-phosphatase (SHIP2) in apoptosis of the hepatocytes, remains unknown. In the present study, we studied the molecular mechanisms linking SHIP2 expression to apoptosis using overexpression or suppression of SHIP2 gene in HepG2 cells exposed to palmitate (0.5 mM). Overexpression of the dominant negative mutant SHIP2 (SHIP2-DN) significantly reduced palmitate-induced apoptosis in HepG2 cells, as these cells had increased cell viability, decreased apoptotic cell death and reduced the activity of caspase-3, cytochrome c and poly (ADP-ribose) polymerase. Overexpression of the wild-type SHIP2 gene led to a massive apoptosis in HepG2 cells. The protection from palmitate-induced apoptosis by SHIP2 inhibition was accompanied by a decrease in the generation of reactive oxygen species (ROS). In addition, SHIP2 inhibition was accompanied by an increased Akt and FOXO-1 phosphorylation, whereas overexpression of the wild-type SHIP2 gene had the opposite effects. Taken together, these findings suggest that SHIP2 expression level is an important determinant of hepatic lipoapotosis and its inhibition can potentially be a target in treatment of hepatic lipoapoptosis in diabetic patients. - Highlights: • Lipoapoptosis is the major contributor to the development of NAFLD. • The PI3-K/Akt pathway regulates apoptosis in different cells. • The role of negative regulator of this pathway, SHIP2 in lipoapoptosis is unknown. • SHIP2 inhibition significantly reduces palmitate-induced apoptosis in HepG2 cells. • SHIP2 inhibition prevents palmitate induced-apoptosis by regulating Akt/FOXO1 pathway.

  7. Investigating ROS sources in male infertility: a common end for numerous pathways.

    PubMed

    Lavranos, G; Balla, M; Tzortzopoulou, A; Syriou, V; Angelopoulou, R

    2012-11-01

    Reactive oxygen species (ROS) are active byproducts of aerobic metabolism. Although they are constantly produced during normal cellular activities in the mitochondria, their action is counteracted by inherent antioxidant systems. This equilibrium is distorted in the case of acute or chronic inflammation, which results in increased ROS production and, ultimately, oxidative stress. In sperm, ROS are produced by both spermatozoa and circulating leucocytes and may be part of normal adaptive reactions, such as the capacitation process. However, a number of external toxicants may also contribute to ROS production in the testis and epididymis, leading to a decrease in sperm viability and motility and, therefore, an increased onset of the male factor of infertility. Such pro-oxidative conditions include, among others, exposure to radiation, extreme temperature, certain drugs, toxins, heavy metals, smoking and biological hazards. The current review paper summarizes the available evidence incriminating ROS and oxidative stress as the underlying pathophysiological mechanism leading to the onset of reproductive toxicity in each of these settings. PMID:22749934

  8. Identification of Novel ROS Inducers: Quinone Derivatives Tethered to Long Hydrocarbon Chains.

    PubMed

    Hong, Yeonsun; Sengupta, Sandip; Hur, Wooyoung; Sim, Taebo

    2015-05-14

    We performed the first synthesis of the 17-carbon chain-tethered quinone moiety 22 (SAN5201) of irisferin A, a natural product exhibiting anticancer activity, and its derivatives. We found that 22 is a potent ROS inducer and cytotoxic agent. Compound 25 (SAN7401), the hydroquinone form of 22, induced a significant release of intracellular ROS and apoptosis (EC50 = 1.3-2.6 μM) in cancer cell lines, including A549 and HCT-116. Compared with the activity of a well-known ROS inducer, piperlongumine, 22 and 25 showed stronger cytotoxicity and higher selectivity over noncancerous cells. Another hydroquinone tethering 12-carbon chain, 26 (SAN4601), generated reduced levels of ROS but showed more potent cytotoxicity (EC50 = 0.8-1.6 μM) in cancer cells, although it lacked selectivity over noncancerous cells, implying that the naturally occurring 17-carbon chain is also crucial for ROS production and a selective anticancer effect. Both 25 and 26 displayed strong, equipotent activities against vemurafenib-resistant SK-Mel2 melanoma cells and p53-deficient H1299 lung cancer cells as well, demonstrating their broad therapeutic potential as anticancer agents. PMID:25826398

  9. Mitochondria and Mitochondrial ROS in Cancer: Novel Targets for Anticancer Therapy.

    PubMed

    Yang, Yuhui; Karakhanova, Svetlana; Hartwig, Werner; D'Haese, Jan G; Philippov, Pavel P; Werner, Jens; Bazhin, Alexandr V

    2016-12-01

    Mitochondria are indispensable for energy metabolism, apoptosis regulation, and cell signaling. Mitochondria in malignant cells differ structurally and functionally from those in normal cells and participate actively in metabolic reprogramming. Mitochondria in cancer cells are characterized by reactive oxygen species (ROS) overproduction, which promotes cancer development by inducing genomic instability, modifying gene expression, and participating in signaling pathways. Mitochondrial and nuclear DNA mutations caused by oxidative damage that impair the oxidative phosphorylation process will result in further mitochondrial ROS production, completing the "vicious cycle" between mitochondria, ROS, genomic instability, and cancer development. The multiple essential roles of mitochondria have been utilized for designing novel mitochondria-targeted anticancer agents. Selective drug delivery to mitochondria helps to increase specificity and reduce toxicity of these agents. In order to reduce mitochondrial ROS production, mitochondria-targeted antioxidants can specifically accumulate in mitochondria by affiliating to a lipophilic penetrating cation and prevent mitochondria from oxidative damage. In consistence with the oncogenic role of ROS, mitochondria-targeted antioxidants are found to be effective in cancer prevention and anticancer therapy. A better understanding of the role played by mitochondria in cancer development will help to reveal more therapeutic targets, and will help to increase the activity and selectivity of mitochondria-targeted anticancer drugs. In this review we summarized the impact of mitochondria on cancer and gave summary about the possibilities to target mitochondria for anticancer therapies. J. Cell. Physiol. 231: 2570-2581, 2016. © 2016 Wiley Periodicals, Inc. PMID:26895995

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

    PubMed

    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

    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

  11. ROS Regulate Cardiac Function via a Distinct Paracrine Mechanism

    PubMed Central

    Lim, Hui-Ying; Wang, Weidong; Chen, Jianming; Ocorr, Karen; Bodmer, Rolf

    2014-01-01

    SUMMARY Reactive oxygen species (ROS) can act cell autonomously and in a paracrine manner by diffusing into nearby cells. Here, we reveal a ROS-mediated paracrine signaling mechanism that does not require entry of ROS into target cells. We found that under physiological conditions, nonmyocytic pericardial cells (PCs) of the Drosophila heart contain elevated levels of ROS compared to the neighboring cardiomyocytes (CMs). We show that ROS in PCs act in a paracrine manner to regulate normal cardiac function, not by diffusing into the CMs to exert their function, but by eliciting a downstream D-MKK3-D-p38 MAPK signaling cascade in PCs that acts on the CMs to regulate their function. We find that ROS-D-p38 signaling in PCs during development is also important for establishing normal adult cardiac function. Our results provide evidence for a previously unrecognized role of ROS in mediating PC/CM interactions that significantly modulates heart function. PMID:24656823

  12. ROS-generating/ARE-activating capacity of metals in roadway particulate matter deposited in urban environment.

    PubMed

    Shuster-Meiseles, Timor; Shafer, Martin M; Heo, Jongbae; Pardo, Michal; Antkiewicz, Dagmara S; Schauer, James J; Rudich, Assaf; Rudich, Yinon

    2016-04-01

    In this study we investigated the possible causal role for soluble metal species extracted from roadway traffic emissions in promoting particulate matter (PM)-induced reactive oxygen species (ROS) production and antioxidant response element (ARE) promoter activation. To this end, these responses have been evaluated in alveolar macrophage and epithelial lung cells that have been exposed to 'Unfiltered', 'Filtered' and 'Filtered+Chelexed' water extracts of PM samples collected from the roadway urban environments of Thessaloniki, Milan and London. Except for Thessaloniki, our results demonstrate that filtration resulted in a minor decrease in ROS activity of the fine PM fraction, suggesting that ROS activity is attributed mainly to water-soluble PM species. In contrast to ROS, ARE activity was mediated predominantly by the water-soluble component of PM present in both the fine and coarse extracts. Further removal of metals by Chelex treatment from filtered water extracts showed that soluble metal species are the major factors mediating ROS and ARE activities of the soluble fraction, especially in the London PM extracts. Finally, utilizing step-wise multiple-regression analysis, we show that 87% and 78% of the total variance observed in ROS and ARE assays, respectively, is accounted for by changes in soluble metal concentration. Using a statistical analysis we find that As, Zn and Fe best predict the ROS-generating/ARE-activating capacity of the near roadway particulate matter in the pulmonary cells studied. Collectively, our findings imply that soluble metals present in roadside PM are potential drivers of both pro- and anti-oxidative effects of PM in respiratory tract. PMID:26775006

  13. Cabozantinib overcomes crizotinib resistance in ROS1 fusion positive cancer

    PubMed Central

    Katayama, Ryohei; Kobayashi, Yuka; Friboulet, Luc; Lockerman, Elizabeth. L.; Koike, Sumie; Shaw, Alice T.; Engelman, Jeffrey A.; Fujita, Naoya

    2014-01-01

    Purpose ROS1 rearrangement leads to constitutive ROS1 activation with potent transforming activity. In an ongoing phase 1 trial, the ALK tyrosine kinase inhibitor (TKI) crizotinib shows remarkable initial responses in patients with non-small cell lung cancer (NSCLC) harboring ROS1 fusions; however, cancers eventually develop crizotinib resistance due to acquired mutations such as G2032R in ROS1. Thus, understanding the crizotinib resistance mechanisms in ROS1 rearranged NSCLC and identification of therapeutic strategies to overcome the resistance are required. Experimental Design The sensitivity of CD74-ROS1-transformed Ba/F3 cells to multiple ALK inhibitors was examined. Acquired ROS1 inhibitor resistant mutations in CD74-ROS1 fusion were screened by N-ethyl-N-nitrosourea mutagenesis with Ba/F3 cells. To overcome the resistance mutation, we performed high throughput drug screening with small molecular inhibitors and anticancer drugs used in clinical practice or being currently tested in clinical trials. The effect of the identified drug was assessed in the CD74-ROS1 mutant Ba/F3 cells and crizotinib resistant patient-derived cancer cells (MGH047) harboring G2032R mutated CD74-ROS1. Results We identified multiple novel crizotinib resistance mutations in the ROS1 kinase domain including the G2032R mutation. As the result of high-throughput drug screening, we found that the cMET/RET/VEGFR inhibitor cabozantinib (XL184) effectively inhibited the survival of CD74-ROS1-WT and resistant mutants harboring Ba/F3 and MGH047 cells. Furthermore, cabozantinib could overcome all the resistance by all newly identified secondary mutations. Conclusions We developed a comprehensive model of acquired resistance to ROS1 inhibitors in NSCLC with ROS1 rearrangement and identified cabozantinib as a therapeutic strategy to overcome the resistance. PMID:25351743

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

    PubMed Central

    Felty, Quentin

    2006-01-01

    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 μM) and xanthine oxidase inhibitor allopurinol (50 μM). Inhibitors of NAD(P)H 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 μM) 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

  15. KRAS-driven ROS promote malignant transformation

    PubMed Central

    Suh, Yongjoon; Lee, Su-Jae

    2015-01-01

    The mechanism underlying KRAS (Kirsten rat sarcoma viral oncogene homolog)-driven cellular transformation remains unclear because of the complexity of its downstream effectors. Park et al. recently reported that levels of reactive oxygen species (ROS) are increased by KRAS and are responsible for KRAS-driven malignant transformation, and further identified the signaling cascade involved as KRAS/p38/PDPK1/PKCδ/p47phox/NOX1. These findings provide new insight into the molecular mechanisms governing KRAS-driven malignant transformation. PMID:27308397

  16. Environmental changes in oxygen tension reveal ROS-dependent neurogenesis and regeneration in the adult newt brain.

    PubMed

    Hameed, L Shahul; Berg, Daniel A; Belnoue, Laure; Jensen, Lasse D; Cao, Yihai; Simon, András

    2015-01-01

    Organisms need to adapt to the ecological constraints in their habitat. How specific processes reflect such adaptations are difficult to model experimentally. We tested whether environmental shifts in oxygen tension lead to events in the adult newt brain that share features with processes occurring during neuronal regeneration under normoxia. By experimental simulation of varying oxygen concentrations, we show that hypoxia followed by re-oxygenation lead to neuronal death and hallmarks of an injury response, including activation of neural stem cells ultimately leading to neurogenesis. Neural stem cells accumulate reactive oxygen species (ROS) during re-oxygenation and inhibition of ROS biosynthesis counteracts their proliferation as well as neurogenesis. Importantly, regeneration of dopamine neurons under normoxia also depends on ROS-production. These data demonstrate a role for ROS-production in neurogenesis in newts and suggest that this role may have been recruited to the capacity to replace lost neurons in the brain of an adult vertebrate. PMID:26485032

  17. ROS, Cell Senescence, and Novel Molecular Mechanisms in Aging and Age-Related Diseases

    PubMed Central

    Davalli, Pierpaola; Mitic, Tijana; Caporali, Andrea; Lauriola, Angela; D'Arca, Domenico

    2016-01-01

    The aging process worsens the human body functions at multiple levels, thus causing its gradual decrease to resist stress, damage, and disease. Besides changes in gene expression and metabolic control, the aging rate has been associated with the production of high levels of Reactive Oxygen Species (ROS) and/or Reactive Nitrosative Species (RNS). Specific increases of ROS level have been demonstrated as potentially critical for induction and maintenance of cell senescence process. Causal connection between ROS, aging, age-related pathologies, and cell senescence is studied intensely. Senescent cells have been proposed as a target for interventions to delay the aging and its related diseases or to improve the diseases treatment. Therapeutic interventions towards senescent cells might allow restoring the health and curing the diseases that share basal processes, rather than curing each disease in separate and symptomatic way. Here, we review observations on ROS ability of inducing cell senescence through novel mechanisms that underpin aging processes. Particular emphasis is addressed to the novel mechanisms of ROS involvement in epigenetic regulation of cell senescence and aging, with the aim to individuate specific pathways, which might promote healthy lifespan and improve aging. PMID:27247702

  18. Drug-induced reactive oxygen species (ROS) rely on cell membrane properties to exert anticancer effects

    PubMed Central

    Molavian, Hamid R.; Goldman, Aaron; Phipps, Colin J.; Kohandel, Mohammad; Wouters, Bradly G.; Sengupta, Shiladitya; Sivaloganathan, Sivabal

    2016-01-01

    Pharmacological concentrations of small molecule natural products, such as ascorbic acid, have exhibited distinct cell killing outcomes between cancer and normal cells whereby cancer cells undergo apoptosis or necrosis while normal cells are not adversely affected. Here, we develop a mathematical model for ascorbic acid that can be utilized as a tool to understand the dynamics of reactive oxygen species (ROS) induced cell death. We determine that not only do endogenous antioxidants such as catalase contribute to ROS-induced cell death, but also cell membrane properties play a critical role in the efficacy of ROS as a cytotoxic mechanism against cancer cells vs. normal cells. Using in vitro assays with breast cancer cells, we have confirmed that cell membrane properties are essential for ROS, in the form of hydrogen peroxide (H2O2), to induce cell death. Interestingly, we did not observe any correlation between intracellular H2O2 and cell survival, suggesting that cell death by H2O2 is triggered by interaction with the cell membrane and not necessarily due to intracellular levels of H2O2. These findings provide a putative mechanistic explanation for the efficacy and selectivity of therapies such as ascorbic acid that rely on ROS-induced cell death for their anti-tumor properties. PMID:27278439

  19. Mitochondrial Lon protease controls ROS-dependent apoptosis in cardiomyocyte under hypoxia.

    PubMed

    Kuo, Chan-Yen; Chiu, Yi-Chieh; Lee, Alan Yueh-Luen; Hwang, Tsong-Long

    2015-07-01

    Apoptosis of cardiomyocytes, under ischemic conditions, has been identified as an essential process in the progression of heart failure. Under hypoxic conditions, mitochondria can become a threat to the cell because of their capacity to generate reactive oxygen species (ROS). As ROS appear to have a critical role in heart failure, there has been considerable interest in identifying the candidate proteins involved and in developing strategies to reduce oxidative stress. Lon protease (Lon) is a multifunctional protein that mediates protein quality control and stress response in mitochondria. However, comprehensive and detailed studies, on the role of Lon in hypoxia-induced cardiomyocyte apoptosis, have yet to be carried out. In the present study, we demonstrated that hypoxia induced ROS-dependent cardiomyocyte apoptosis. Lon was upregulated in hypoxia-induced cardiomyocytes. Lon downregulation attenuated hypoxia-induced cardiomyocyte apoptosis through a reduction of ROS level. Moreover, overexpression of Lon stimulated ROS production and induced apoptosis under normoxic conditions in cardiomyocytes. Our results identify Lon as a novel regulator of cardiomyocyte fate and offers exciting new insights into the therapeutic potential of hypoxia-induced cardiomyocyte apoptosis. PMID:25922169

  20. Drug-induced reactive oxygen species (ROS) rely on cell membrane properties to exert anticancer effects.

    PubMed

    Molavian, Hamid R; Goldman, Aaron; Phipps, Colin J; Kohandel, Mohammad; Wouters, Bradly G; Sengupta, Shiladitya; Sivaloganathan, Sivabal

    2016-01-01

    Pharmacological concentrations of small molecule natural products, such as ascorbic acid, have exhibited distinct cell killing outcomes between cancer and normal cells whereby cancer cells undergo apoptosis or necrosis while normal cells are not adversely affected. Here, we develop a mathematical model for ascorbic acid that can be utilized as a tool to understand the dynamics of reactive oxygen species (ROS) induced cell death. We determine that not only do endogenous antioxidants such as catalase contribute to ROS-induced cell death, but also cell membrane properties play a critical role in the efficacy of ROS as a cytotoxic mechanism against cancer cells vs. normal cells. Using in vitro assays with breast cancer cells, we have confirmed that cell membrane properties are essential for ROS, in the form of hydrogen peroxide (H2O2), to induce cell death. Interestingly, we did not observe any correlation between intracellular H2O2 and cell survival, suggesting that cell death by H2O2 is triggered by interaction with the cell membrane and not necessarily due to intracellular levels of H2O2. These findings provide a putative mechanistic explanation for the efficacy and selectivity of therapies such as ascorbic acid that rely on ROS-induced cell death for their anti-tumor properties. PMID:27278439

  1. NADPH oxidase-derived ROS and the regulation of pulmonary vessel tone

    PubMed Central

    Frazziano, G.; Champion, H. C.

    2012-01-01

    Pulmonary vessel constriction results from an imbalance between vasodilator and vasoconstrictor factors released by the endothelium including nitric oxide, endothelin, prostanoids, and reactive oxygen species (ROS). ROS, generated by a variety of enzymatic sources (such as mitochondria and NADPH oxidases, a.k.a. Nox), appear to play a pivotal role in vascular homeostasis, whereas elevated levels effect vascular disease. The pulmonary circulation is very sensitive to changes in the partial pressure of oxygen and differs from the systemic circulation in its response to this change. In fact, the pulmonary vessels contract in response to low oxygen tension, whereas systemic vessels dilate. Growing evidence suggests that ROS production and ROS-related pathways may be key factors that underlie this differential response to oxygen tension. A major emphasis of our laboratory is the role of Nox isozymes in cardiovascular disease. In this review, we will focus our attention on the role of Nox-derived ROS in the control of pulmonary vascular tone. PMID:22427511

  2. ATM functions at the peroxisome to induce pexophagy in response to ROS.

    PubMed

    Zhang, Jiangwei; Tripathi, Durga Nand; Jing, Ji; Alexander, Angela; Kim, Jinhee; Powell, Reid T; Dere, Ruhee; Tait-Mulder, Jacqueline; Lee, Ji-Hoon; Paull, Tanya T; Pandita, Raj K; Charaka, Vijaya K; Pandita, Tej K; Kastan, Michael B; Walker, Cheryl Lyn

    2015-10-01

    Peroxisomes are highly metabolic, autonomously replicating organelles that generate reactive oxygen species (ROS) as a by-product of fatty acid β-oxidation. Consequently, cells must maintain peroxisome homeostasis, or risk pathologies associated with too few peroxisomes, such as peroxisome biogenesis disorders, or too many peroxisomes, inducing oxidative damage and promoting diseases such as cancer. We report that the PEX5 peroxisome import receptor binds ataxia-telangiectasia mutated (ATM) and localizes this kinase to the peroxisome. In response to ROS, ATM signalling activates ULK1 and inhibits mTORC1 to induce autophagy. Specificity for autophagy of peroxisomes (pexophagy) is provided by ATM phosphorylation of PEX5 at Ser 141, which promotes PEX5 monoubiquitylation at Lys 209, and recognition of ubiquitylated PEX5 by the autophagy adaptor protein p62, directing the autophagosome to peroxisomes to induce pexophagy. These data reveal an important new role for ATM in metabolism as a sensor of ROS that regulates pexophagy. PMID:26344566

  3. ROS1 Kinase Inhibitors for Molecular-Targeted Therapies.

    PubMed

    Al-Sanea, M M; Abdelazem, A Z; Park, B S; Yoo, K H; Sim, T; Kwon, Y J; Lee, S H

    2016-01-01

    ROS1 is a pivotal transmembrane receptor protein tyrosine kinase which regulates several cellular processes like apoptosis, survival, differentiation, proliferation, cell migration, and transformation. There is increasing evidence supporting that ROS1 plays an important role in different malignancies including glioblastoma, colorectal cancer, gastric adenocarcinoma, inflammatory myofibroblastic tumor, ovarian cancer, angiosarcoma, and non small cell lung cancer; thus, ROS1 has become a potential drug discovery target. ROS1 shares about 49% sequence homology with ALK primary structure; therefore, wide range of ALK kinase inhibitors have shown in vitro inhibitory activity against ROS1 kinase. After Crizotinib approval by FDA for the management of ALK-rearranged lung cancer, ROS1-positive tumors have been focused. Although significant advancements have been achieved in understanding ROS1 function and its signaling pathways plus recent discovery of small molecules modulating ROS1 protein, a vital need of medicinal chemistry efforts is still required to produce selective and potent ROS1 inhibitors as an important therapeutic strategy for different human malignancies. This review focuses on the current knowledge about different scaffolds targeting ROS1 rearrangements, methods to synthesis, and some biological data about the most potent compounds that have delivered various scaffold structures. PMID:26438251

  4. Lysine Methyltransferase SETD7 (SET7/9) Regulates ROS Signaling through mitochondria and NFE2L2/ARE pathway

    PubMed Central

    He, Shuying; Owen, Dafydd R.; Jelinsky, Scott A.; Lin, Lih-Ling

    2015-01-01

    Reactive oxygen species (ROS) homeostasis requires stringent regulation. ROS imbalance, especially ROS accumulation, has profound implications in various disease pathogenesis. Lysine methylation of histone and non-histone proteins has been implicated in various cellular responses. The main objective of this study is to investigate the role of SET domain containing lysine methyltransferase SETD7 (SET7/9) in the regulation of ROS-mediated signaling. Here we report that inhibition of SETD7 with siRNA or a SETD7 small molecule inhibitor in both macrophages and a human bronchial epithelial cell line (Beas-2B) were able to counter NF-ĸB-induced oxidative stress and pro-inflammatory cytokine production. Meanwhile, inhibition of SETD7 elevates mitochondria antioxidant functions via negative regulation of PPARGC1A and NFE2L2. Using a co-expression system and purified proteins, we detected direct interaction between SETD7 and NFE2L2. These results indicate that lysine methylation by SETD7 is important for the fine-tuning of ROS signaling through its regulation on pro-inflammatory responses, mitochondrial function and the NFE2L2/ARE pathway. Up-regulation of multiple antioxidant genes and improved ROS clearance by inhibition of SETD7 suggests the potential benefit of targeting SETD7 in treating ROS-associated diseases. PMID:26435321

  5. Patterns of ROS Accumulation in the Stigmas of Angiosperms and Visions into Their Multi-Functionality in Plant Reproduction

    PubMed Central

    Zafra, Adoración; Rejón, Juan D.; Hiscock, Simon J.; Alché, Juan de Dios

    2016-01-01

    Accumulation of reactive oxygen species (ROS) in the stigma of several plant species has been investigated. Four developmental stages (unopened flower buds, recently opened flowers, dehiscent anthers, and flowers after fertilization) were analyzed by confocal laser scanning microscopy using the ROS-specific probe DCFH2-DA. In all plants scrutinized, the presence of ROS in the stigmas was detected at higher levels during those developmental phases considered “receptive” to pollen interaction. In addition, these molecules were also present at early (unopened flower) or later (post-fertilization) stages, by following differential patterns depending on the different species. The biological significance of the presence ROS may differ between these stages, including defense functions, signaling and senescence. Pollen-stigma signaling is likely involved in the different mechanisms of self-incompatibility in these plants. The study also register a general decrease in the presence of ROS in the stigmas upon pollination, when NO is supposedly produced in an active manner by pollen grains. Finally, the distribution of ROS in primitive Angiosperms of the genus Magnolia was determined. The production of such chemical species in these plants was several orders of magnitude higher than in the remaining species evoking a massive displacement toward the defense function. This might indicate that signaling functions of ROS/NO in the stigma evolved later, as fine tune likely involved in specialized interactions like self-incompatibility. PMID:27547207

  6. Patterns of ROS Accumulation in the Stigmas of Angiosperms and Visions into Their Multi-Functionality in Plant Reproduction.

    PubMed

    Zafra, Adoración; Rejón, Juan D; Hiscock, Simon J; Alché, Juan de Dios

    2016-01-01

    Accumulation of reactive oxygen species (ROS) in the stigma of several plant species has been investigated. Four developmental stages (unopened flower buds, recently opened flowers, dehiscent anthers, and flowers after fertilization) were analyzed by confocal laser scanning microscopy using the ROS-specific probe DCFH2-DA. In all plants scrutinized, the presence of ROS in the stigmas was detected at higher levels during those developmental phases considered "receptive" to pollen interaction. In addition, these molecules were also present at early (unopened flower) or later (post-fertilization) stages, by following differential patterns depending on the different species. The biological significance of the presence ROS may differ between these stages, including defense functions, signaling and senescence. Pollen-stigma signaling is likely involved in the different mechanisms of self-incompatibility in these plants. The study also register a general decrease in the presence of ROS in the stigmas upon pollination, when NO is supposedly produced in an active manner by pollen grains. Finally, the distribution of ROS in primitive Angiosperms of the genus Magnolia was determined. The production of such chemical species in these plants was several orders of magnitude higher than in the remaining species evoking a massive displacement toward the defense function. This might indicate that signaling functions of ROS/NO in the stigma evolved later, as fine tune likely involved in specialized interactions like self-incompatibility. PMID:27547207

  7. Oestrous sheep serum balances ROS levels to supply in vitro capacitation of ram spermatozoa.

    PubMed

    Del Olmo, E; García-Álvarez, O; Maroto-Morales, A; Ramón, M; Iniesta-Cuerda, M; Martinez-Pastor, F; Montoro, V; Soler, A J; Garde, J J; Fernández-Santos, M R

    2016-10-01

    Reactive oxygen species (ROS) are fundamental for intracellular signalling. In spermatozoa, they are involved both to apoptosis and to capacitation, and changes in ROS levels can alter the balance between these two processes. Oestrous sheep serum (OSS) is considered an efficient agent for in vitro capacitation of ram spermatozoa. We have explored the effects of OSS on ram sperm physiology, especially on ROS production, during in vitro capacitation. Semen samples from 15 rams were cryopreserved. After thawing, samples were submitted to four treatments: control (CTL), 10% OSS supplementation for in vitro sperm capacitation, caspase inhibitor (INH, Z-VAD-FMK 100 μM) and OSS (10%) plus caspase inhibitor (I + E). Sperm samples were incubated for 30 min at 38.5°C and 5% CO2 and evaluated motility and kinetic parameters by computer-assisted semen analysis (CASA) and viability (propidium iodide), apoptotic-like membrane changes (YO-PRO-1), acrosomal status (PNA-FITC), intracellular calcium (FLUO-3), membrane fluidity (M540) and ROS production (CM-H2 DCFDA) by flow cytometry. OSS induced changes in kinetic parameters compatible with capacitation, with a decrease in the percentage of progressive motility and linearity, and an increase in the amplitude of the lateral displacement of the sperm head (p < .05). Moreover, OSS increased the proportion of M540+ viable spermatozoa, YO-PRO-1+ and acrosome-reacted spermatozoa (p < .05). After incubation, OSS and I+E achieved lower ROS levels (p < .05). Ca(2+) levels did not change with the incubation, but were slightly higher (p < .05) when both OSS and the inhibitor were present. We suggest that OSS may modulate ROS levels, allowing intracellular signalling for capacitation to occur while preventing higher levels that could trigger apoptosis. PMID:27491678

  8. Monolayer expansion induces an oxidative metabolism and ROS in chondrocytes

    SciTech Connect

    Heywood, H.K. Lee, D.A.

    2008-08-22

    This study tests the hypothesis that articular chondrocytes shift from a characteristically glycolytic to an oxidative energy metabolism during population expansion in monolayer. Bovine articular chondrocytes were cultured in monolayer under standard incubator conditions for up to 14 days. Cellular proliferation, oxygen consumption, lactate production, protein content, ROS generation and mitochondrial morphology were examined. Lactate release increased {approx}5-fold within 1 week, but this was limited to {approx}2-fold increase when normalized to cellular protein content. By contrast, per cell oxidative phosphorylation increased 98-fold in 1 week. The increase in oxidative phosphorylation was evident within 24 h, preceding cell proliferation and was associated with augmented reactive oxygen species generation. The autologous chondrocyte implantation procedure requires 14-21 days for population expansion. The alterations in metabolic phenotype we report within 7 days in vitro are thus pertinent to autologous chondrocyte implantation with significant implications for the chondrocyte functionality.

  9. Bioreductively Activated Reactive Oxygen Species (ROS) Generators as MRSA Inhibitors.

    PubMed

    Khodade, Vinayak S; Sharath Chandra, Mallojjala; Banerjee, Ankita; Lahiri, Surobhi; Pulipeta, Mallikarjuna; Rangarajan, Radha; Chakrapani, Harinath

    2014-07-10

    The number of cases of drug resistant Staphylococcus aureus infections is on the rise globally and new strategies to identify drug candidates with novel mechanisms of action are in urgent need. Here, we report the synthesis and evaluation of a series of benzo[b]phenanthridine-5,7,12(6H)-triones, which were designed based on redox-active natural products. We find that the in vitro inhibitory activity of 6-(prop-2-ynyl)benzo[b]phenanthridine-5,7,12(6H)-trione (1f) against methicillin-resistant Staphylococcus aureus (MRSA), including a panel of patient-derived strains, is comparable or better than vancomycin. We show that the lead compound generates reactive oxygen species (ROS) in the cell, contributing to its antibacterial activity. PMID:25050164

  10. ROS Function in Redox Signaling and Oxidative Stress

    PubMed Central

    Schieber, Michael; Chandel, Navdeep S.

    2014-01-01

    Oxidative stress refers to elevated intracellular levels of reactive oxygen species (ROS) that cause damage to lipids, proteins and DNA. Oxidative stress has been linked to a myriad of pathologies. However, elevated ROS are also signaling molecules i.e. redox biology that maintain physiological functions. In this review we discuss the two faces of ROS, redox signaling and oxidative stress, and their contribution to both physiological and pathological conditions. Redox biology refers to low levels of ROS that activate signaling pathways to initiate biological processes while oxidative stress denotes high levels of ROS that incur damage to DNA, protein or lipids. Thus, the response to ROS displays hormesis. The In this review, we argue that redox biology, rather than oxidative stress, underlies physiological and pathological conditions. PMID:24845678

  11. Cysteines under ROS attack in plants: a proteomics view.

    PubMed

    Akter, Salma; Huang, Jingjing; Waszczak, Cezary; Jacques, Silke; Gevaert, Kris; Van Breusegem, Frank; Messens, Joris

    2015-05-01

    Plants generate reactive oxygen species (ROS) as part of their metabolism and in response to various external stress factors, potentially causing significant damage to biomolecules and cell structures. During the course of evolution, plants have adapted to ROS toxicity, and use ROS as signalling messengers that activate defence responses. Cysteine (Cys) residues in proteins are one of the most sensitive targets for ROS-mediated post-translational modifications, and they have become key residues for ROS signalling studies. The reactivity of Cys residues towards ROS, and their ability to react to different oxidation states, allow them to appear at the crossroads of highly dynamic oxidative events. As such, a redox-active cysteine can be present as S-glutathionylated (-SSG), disulfide bonded (S-S), sulfenylated (-SOH), sulfinylated (-SO2H), and sulfonylated (-SO3H). The sulfenic acid (-SOH) form has been considered as part of ROS-sensing pathways, as it leads to further modifications which affect protein structure and function. Redox proteomic studies are required to understand how and why cysteines undergo oxidative post-translational modifications and to identify the ROS-sensor proteins. Here, we update current knowledge of cysteine reactivity with ROS. Further, we give an overview of proteomic techniques that have been applied to identify different redox-modified cysteines in plants. There is a particular focus on the identification of sulfenylated proteins, which have the potential to be involved in plant signal transduction. PMID:25750420

  12. Loss of the tumor suppressor Hace1 leads to ROS-dependent glutamine addiction.

    PubMed

    Cetinbas, N; Daugaard, M; Mullen, A R; Hajee, S; Rotblat, B; Lopez, A; Li, A; DeBerardinis, R J; Sorensen, P H

    2015-07-23

    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

  13. ROS play a critical role in the differentiation of alternatively activated macrophages and the occurrence of tumor-associated macrophages

    PubMed Central

    Zhang, Yan; Choksi, Swati; Chen, Kun; Pobezinskaya, Yelena; Linnoila, Ilona; Liu, Zheng-Gang

    2013-01-01

    Differentiation to different types of macrophages determines their distinct functions. Tumor-associated macrophages (TAMs) promote tumorigenesis owing to their proangiogenic and immune-suppressive functions similar to those of alternatively activated (M2) macrophages. We report that reactive oxygen species (ROS) production is critical for macrophage differentiation and that inhibition of superoxide (O2−) production specifically blocks the differentiation of M2 macrophages. We found that when monocytes are triggered to differentiate, O2− is generated and is needed for the biphasic ERK activation, which is critical for macrophage differentiation. We demonstrated that ROS elimination by butylated hydroxyanisole (BHA) and other ROS inhibitors blocks macrophage differentiation. However, the inhibitory effect of ROS elimination on macrophage differentiation is overcome when cells are polarized to classically activated (M1), but not M2, macrophages. More importantly, the continuous administration of the ROS inhibitor BHA efficiently blocked the occurrence of TAMs and markedly suppressed tumorigenesis in mouse cancer models. Targeting TAMs by blocking ROS can be a potentially effective method for cancer treatment. PMID:23752925

  14. Generation of reactive oxygen species (ROS) is a key factor for stimulation of macrophage proliferation by ceramide 1-phosphate

    SciTech Connect

    Arana, Lide; Gangoiti, Patricia; Ouro, Alberto; Rivera, Io-Guane; Ordonez, Marta; Trueba, Miguel; Lankalapalli, Ravi S.; Bittman, Robert; Gomez-Munoz, Antonio

    2012-02-15

    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 A{sub 2} and protein kinase C-{alpha}, 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-{alpha} and cPLA{sub 2}-{alpha} in this pathway. -- Highlights: Black-Right-Pointing-Pointer Ceramide 1-phosphate (C1P) stimulates reactive oxygen species (ROS) formation. Black-Right-Pointing-Pointer The enzyme responsible for ROS generation by C1P in macrophages is NADPH oxidase. Black-Right-Pointing-Pointer NADPH oxidase lies downstream of cPLA{sub 2}-{alpha} and PKC-{alpha} in this pathway. Black-Right-Pointing-Pointer ROS generation is essential for the stimulation of macrophage proliferation by C1P.

  15. ROS and Brain Gliomas: An Overview of Potential and Innovative Therapeutic Strategies.

    PubMed

    Rinaldi, Mariagrazia; Caffo, Maria; Minutoli, Letteria; Marini, Herbert; Abbritti, Rosaria Viola; Squadrito, Francesco; Trichilo, Vincenzo; Valenti, Andrea; Barresi, Valeria; Altavilla, Domenica; Passalacqua, Marcello; Caruso, Gerardo

    2016-01-01

    Reactive oxygen species (ROS) represent reactive products belonging to the partial reduction of oxygen. It has been reported that ROS are involved in different signaling pathways to control cellular stability. Under normal conditions, the correct function of redox systems leads to the prevention of cell oxidative damage. When ROS exceed the antioxidant defense system, cellular stress occurs. The cellular redox impairment is strictly related to tumorigenesis. Tumor cells, through the generation of hydrogen peroxide, tend to the alteration of cell cycle phases and, finally to cancer progression. In adults, the most common form of primary malignant brain tumors is represented by gliomas. The gliomagenesis is characterized by numerous molecular processes all characterized by an altered production of growth factor receptors. The difficulty to treat brain cancer depends on several biological mechanisms such as failure of drug delivery through the blood-brain barrier, tumor response to chemotherapy, and intrinsic resistance of tumor cells. Understanding the mechanisms of ROS action could allow the formulation of new therapeutic protocols to treat brain gliomas. PMID:27338365

  16. ROS and Brain Gliomas: An Overview of Potential and Innovative Therapeutic Strategies

    PubMed Central

    Rinaldi, Mariagrazia; Caffo, Maria; Minutoli, Letteria; Marini, Herbert; Abbritti, Rosaria Viola; Squadrito, Francesco; Trichilo, Vincenzo; Valenti, Andrea; Barresi, Valeria; Altavilla, Domenica; Passalacqua, Marcello; Caruso, Gerardo

    2016-01-01

    Reactive oxygen species (ROS) represent reactive products belonging to the partial reduction of oxygen. It has been reported that ROS are involved in different signaling pathways to control cellular stability. Under normal conditions, the correct function of redox systems leads to the prevention of cell oxidative damage. When ROS exceed the antioxidant defense system, cellular stress occurs. The cellular redox impairment is strictly related to tumorigenesis. Tumor cells, through the generation of hydrogen peroxide, tend to the alteration of cell cycle phases and, finally to cancer progression. In adults, the most common form of primary malignant brain tumors is represented by gliomas. The gliomagenesis is characterized by numerous molecular processes all characterized by an altered production of growth factor receptors. The difficulty to treat brain cancer depends on several biological mechanisms such as failure of drug delivery through the blood-brain barrier, tumor response to chemotherapy, and intrinsic resistance of tumor cells. Understanding the mechanisms of ROS action could allow the formulation of new therapeutic protocols to treat brain gliomas. PMID:27338365

  17. Role of Nox4 and p67phox subunit of Nox2 in ROS production in response to increased tubular flow in the mTAL of Dahl salt-sensitive rats.

    PubMed

    Zheleznova, Nadezhda N; Yang, Chun; Cowley, Allen W

    2016-08-01

    Nox4 and Nox2 are the most abundant NADPH oxidases (Nox) in the kidney and have been shown to contribute to hypertension, renal oxidative stress, and injury in Dahl salt-sensitive (SS) hypertensive rats. The present study focused on the role of Nox4 and p67phox/Nox2 in the generation of H2O2 and O2 (·-) in the renal medullary thick ascending limb of Henle (mTAL) of SS rats in response to increasing luminal flow (from 5 to 20 nl/min). Nox4 and p67phox/Nox2 genes were found to be expressed in the mTAL of SS rats. Responses of SS rats were compared with those of SS rats with knockout of Nox4 (SS(Nox4-/-)) or functional mutation of p67phox (SS(p67phox-/-)). Nox4 was the dominant source of increased intracellular H2O2 production in response to increased luminal flow as determined using the fluorescent dye peroxyfluor 6-AM (PF6-AM). The rate of mitochondrial H2O2 production [as determined by mitochondria peroxy yellow 1 (mitoPY1)] was also significantly reduced in SS(Nox4-/-) compared with SS rats, but not in SS(p67phox-/-) rats. In contrast, intracellular superoxide (O2 (·-)) production (the ratio of ethidium to dihydroethidium) in the mTAL of SS(Nox4-/-) rats was nearly identical to that of SS rats in response to luminal flow, indicating that Nox4 made no measurable contribution. mTAL O2 (·-) production was reduced in SS(p67phox-/-) compared with SS rats at the lower luminal flow of 5 nl/min and progressively increased when perfusion was changed to 20 nl/min. We conclude that increased mTAL luminal flow results in increases in intracellular and mitochondrial H2O2, which are dependent on the presence of Nox4, and that p67phox/Nox2 accounts solely for increases in O2 (·-) production. PMID:27279484

  18. Amyloid β25-35 induced ROS-burst through NADPH oxidase is sensitive to iron chelation in microglial Bv2 cells.

    PubMed

    Part, Kristin; Künnis-Beres, Kai; Poska, Helen; Land, Tiit; Shimmo, Ruth; Zetterström Fernaeus, Sandra

    2015-12-10

    Iron chelation therapy and inhibition of glial nicotinamide adenine dinucleotide phosphate (NADPH) oxidase can both represent possible routes for Alzheimer's disease modifying therapies. The metal hypothesis is largely focused on direct binding of metals to the N-terminal hydrophilic 1-16 domain peptides of Amyloid beta (Aβ) and how they jointly give rise to reactive oxygen species (ROS) production. The cytotoxic effects of Aβ through ROS and metals are mainly studied in neuronal cells using full-length Aβ1-40/42 peptides. Here we study cellularly-derived ROS during 2-60min in response to non-metal associated mid domain Aβ25-35 in microglial Bv2 cells by fluorescence based spectroscopy. We analyze if Aβ25-35 induce ROS production through NADPH oxidase and if the production is sensitive to iron chelation. NADPH oxidase inhibitor diphenyliodonium (DPI) is used to confirm the production of ROS through NADPH oxidase. We modulate cellular iron homeostasis by applying cell permeable iron chelators desferrioxamine (DFO) and deferiprone (DFP). NADPH oxidase subunit gp91-phox level was analyzed by Western blotting. Our results show that Aβ25-35 induces strong ROS production through NADPH oxidase in Bv2 microglial cells. Intracellular iron depletion resulted in restrained Aβ25-35 induced ROS. PMID:26505916

  19. Mouse Model for ROS1-Rearranged Lung Cancer

    PubMed Central

    Takahashi, Hiroyuki; Nakamura, Hiromi; Hama, Natsuko; Kohno, Takashi; Tsuta, Koji; Yoshida, Akihiko; Asamura, Hisao; Mutoh, Michihiro; Hosoda, Fumie; Tsuda, Hitoshi; Shibata, Tatsuhiro

    2013-01-01

    Genetic rearrangement of the ROS1 receptor tyrosine kinase was recently identified as a distinct molecular signature for human non-small cell lung cancer (NSCLC). However, direct evidence of lung carcinogenesis induced by ROS1 fusion genes remains to be verified. The present study shows that EZR-ROS1 plays an essential role in the oncogenesis of NSCLC harboring the fusion gene. EZR-ROS1 was identified in four female patients of lung adenocarcinoma. Three of them were never smokers. Interstitial deletion of 6q22–q25 resulted in gene fusion. Expression of the fusion kinase in NIH3T3 cells induced anchorage-independent growth in vitro, and subcutaneous tumors in nude mice. This transforming ability was attributable to its kinase activity. The ALK/MET/ROS1 kinase inhibitor, crizotinib, suppressed fusion-induced anchorage-independent growth of NIH3T3 cells. Most importantly, established transgenic mouse lines specifically expressing EZR-ROS1 in lung alveolar epithelial cells developed multiple adenocarcinoma nodules in both lungs at an early age. These data suggest that the EZR-ROS1 is a pivotal oncogene in human NSCLC, and that this animal model could be valuable for exploring therapeutic agents against ROS1-rearranged lung cancer. PMID:23418494

  20. A Key Role for Mg2+ in TRPM7’s Control of ROS Levels During Cell Stress

    PubMed Central

    Chen, Hsiang-Chin; Su, Li-Ting; González-Pagán, Omayra; Overton, Jeffrey D.; Runnels, Loren W.

    2012-01-01

    SYNOPSIS The TRPM7 channel has been shown to play a pivotal role in cell survival during brain ischemia as well as in the survival of other cell types challenged with apoptotic stimuli. Ca2+ is thought to be central to the channel’s ability to regulate reactive oxygen species (ROS) production. However, channel-mediated entry of Mg2+ and Zn2+ have also been implicated in cell death. Here we show that depletion of TRPM7 by RNA interference in fibroblasts increases cell resistance to apoptotic stimuli by decreasing ROS levels in a Mg2+-dependent manner. Depletion of TRPM7 lowered cellular Mg2+, decreased the concentration of ROS and lessened p38 MAP kinase and JNK activation as well as decreased caspase-3 activation and PARP cleavage in response to apoptotic stimuli. Re-expression of TRPM7 or of a kinase-inactive mutant of TRPM7 in TRPM7-knockdown cells increased cellular Mg2+ and ROS levels, as did expression of the Mg2+ transporter SLC41A2. In addition, expression of SLC41A2 increased TRPM7-knockdown cells’ sensitivity to apoptotic stimuli as well as boosted ROS generation in response to cell stress. Together these data uncover an essential role for Mg2+ in TRPM7’s control of cell survival and in the regulation of cellular ROS levels. PMID:22587440

  1. ROS Involves the Fungicidal Actions of Thymol against Spores of Aspergillus flavus via the Induction of Nitric Oxide

    PubMed Central

    Shen, Qingshan; Zhou, Wei; Li, Hongbo; Hu, Liangbin; Mo, Haizhen

    2016-01-01

    Aspergillus flavus is a well-known pathogenic fungus for both crops and human beings. The acquisition of resistance to azoles by A. flavus is leading to more failures occurring in the prevention of infection by A. flavus. In this study, we found that thymol, one of the major chemical constituents of the essential oil of Monarda punctate, had efficient fungicidal activity against A. flavus and led to sporular lysis. Further studies indicated that thymol treatment induced the generation of both ROS and NO in spores, whereas NO accumulation was far later than ROS accumulation in response to thymol. By blocking ROS production with the inhibitors of NADPH oxidase, NO generation was also significantly inhibited in the presence of thymol, which indicated that ROS induced NO generation in A. flavus in response to thymol treatment. Moreover, the removal of either ROS or NO attenuated lysis and death of spores exposed to thymol. The addition of SNP (exogenous NO donor) eliminated the protective effects of the inhibitors of NADPH oxidase on thymol-induced lysis and death of spores. Taken together, it could be concluded that ROS is involved in spore death induced by thymol via the induction of NO. PMID:27196096

  2. Emodin augments cisplatin cytotoxicity in platinum-resistant ovarian cancer cells via ROS-dependent MRP1 downregulation.

    PubMed

    Ma, Jun; Yang, Jie; Wang, Chao; Zhang, Nan; Dong, Ying; Wang, Chengjie; Wang, Yu; Lin, Xinjian

    2014-01-01

    The intracellular level of reactive oxygen species (ROS) is closely associated with chemosensitivity of cancer cells. Overexpression of ATP binding cassette transporter MRP1 is correlated with resistance to platinum drugs. In this study, we tested the hypothesis that emodin, a potent ROS generator, may increase sensitivity of cisplatin-(cDDP-) resistant ovarian carcinoma cells to cDDP cytotoxicity via ROS-mediated suppression of MRP1 expression. Using the isogenic pair of the human ovarian carcinoma cell line COC1 and its cDDP resistant variant COC1/DDP, we found that ROS level in the cDDP-sensitive ovarian cancer cells was significantly higher than that in the cDDP-resistant cells. Emodin enhanced ROS production in COC1/DDP cells and consequently sensitized them to cDDP-induced apoptosis. These effects were reversed by addition of the antioxidant N-acetyl-L-cysteine (NAC). Cotreatment with emodin and cDDP inhibited the tumor growth in vivo by increasing tumor cell apoptosis. The emodin-enhanced cDDP cytotoxicity was attributable to downregulation of multidrug resistance-related protein 1 (MRP1) expression. Together, these results suggest that emodin could act as an adjunct to enhance the anticancer effect of cDDP likely through ROS-related downregulation of MRP1 expression, and may be of therapeutic potential in cDDP-refractory ovarian carcinomas. PMID:25580427

  3. Thermosensitive Polypeptide Hydrogels as a Platform for ROS-Triggered Cargo Release with Innate Cytoprotective Ability under Oxidative Stress.

    PubMed

    Xu, Qinghua; He, Chaoliang; Ren, Kaixuan; Xiao, Chunsheng; Chen, Xuesi

    2016-08-01

    Reactive oxygen species (ROS) play important roles in cell signaling pathways, while increased production of ROS may disrupt cellular homeostasis, giving rise to a series of diseases. Therefore, materials responding to ROS at physiological levels are of great significance. In this work, a novel ROS-responsive thermogelling hydrogel based on methoxy poly(ethylene glycol)-poly(l-methionine) diblock copolymers is designed and synthesized. The mechanism for solution-to-hydrogel (sol-gel) phase transitions of the copolymer aqueous solutions is studied. Incubation of the hydrogels in the presence of peroxide hydrogen (H2 O2 ) displays a H2 O2 -responsive degradation process. The hydrogels containing Rhodamine 6G exhibit sustained release profiles that are accelerated in response to H2 O2 . An innate cytoprotective ability of the hydrogels is revealed by incubation of L929 cells with the hydrogels under oxidative stress, which reduces H2 O2 -mediated cell death. ROS produced by activated macrophages can accelerate the erosion of the hydrogel, suggesting that the hydrogel is also responsive to pathological level of H2 O2 . Meanwhile, the poly(l-methionine)-based hydrogels degrade within 6 weeks after subcutaneous injection into rats, with a good biocompatibility in vivo. Overall, the injectable, ROS-responsive hydrogels may serve as promising platforms for sustained drug delivery and cell-based therapies in treatment of diseases with local oxidative stress. PMID:27283999

  4. ROS Involves the Fungicidal Actions of Thymol against Spores of Aspergillus flavus via the Induction of Nitric Oxide.

    PubMed

    Shen, Qingshan; Zhou, Wei; Li, Hongbo; Hu, Liangbin; Mo, Haizhen

    2016-01-01

    Aspergillus flavus is a well-known pathogenic fungus for both crops and human beings. The acquisition of resistance to azoles by A. flavus is leading to more failures occurring in the prevention of infection by A. flavus. In this study, we found that thymol, one of the major chemical constituents of the essential oil of Monarda punctate, had efficient fungicidal activity against A. flavus and led to sporular lysis. Further studies indicated that thymol treatment induced the generation of both ROS and NO in spores, whereas NO accumulation was far later than ROS accumulation in response to thymol. By blocking ROS production with the inhibitors of NADPH oxidase, NO generation was also significantly inhibited in the presence of thymol, which indicated that ROS induced NO generation in A. flavus in response to thymol treatment. Moreover, the removal of either ROS or NO attenuated lysis and death of spores exposed to thymol. The addition of SNP (exogenous NO donor) eliminated the protective effects of the inhibitors of NADPH oxidase on thymol-induced lysis and death of spores. Taken together, it could be concluded that ROS is involved in spore death induced by thymol via the induction of NO. PMID:27196096

  5. Protective Effects of Carvedilol and Vitamin C against Azithromycin-Induced Cardiotoxicity in Rats via Decreasing ROS, IL1-β, and TNF-α Production and Inhibiting NF-κB and Caspase-3 Expression

    PubMed Central

    El-Shitany, Nagla A.; El-Desoky, Karema

    2016-01-01

    The Food and Drug Administration recently warned of the fatal cardiovascular risks of azithromycin in humans. In addition, a recently published study documented azithromycin-induced cardiotoxicity in rats. This study aimed to justify the exact cardiovascular events accompanying azithromycin administration in rats, focusing on electrocardiographic, biochemical, and histopathological changes. In addition, the underlying mechanisms were studied regarding reactive oxygen species production, cytokine release, and apoptotic cell-death. Finally, the supposed protective effects of both carvedilol and vitamin C were assessed. Four groups of rats were used: (1) control, (2) azithromycin, (3) azithromycin + carvedilol, and (4) azithromycin + vitamin C. Azithromycin resulted in marked atrophy of cardiac muscle fibers and electrocardiographic segment alteration. It increased the heart rate, lactate dehydrogenase, creatine phosphokinase, malondialdehyde, nitric oxide, interleukin-1 beta (IL1-β), tumor necrosis factor alpha (TNF-α), nuclear factor kappa beta (NF-κB), and caspase-3. It decreased reduced glutathione, glutathione peroxidase, and superoxide dismutase. Carvedilol and vitamin C prevented most of the azithromycin-induced electrocardiographic and histopathological changes. Carvedilol and vitamin C decreased lactate dehydrogenase, malondialdehyde, IL1-β, TNF-α, NF-κB, and caspase-3. Both agents increased glutathione peroxidase. This study shows that both carvedilol and vitamin C protect against azithromycin-induced cardiotoxicity through antioxidant, immunomodulatory, and antiapoptotic mechanisms. PMID:27274777

  6. Protective Effects of Carvedilol and Vitamin C against Azithromycin-Induced Cardiotoxicity in Rats via Decreasing ROS, IL1-β, and TNF-α Production and Inhibiting NF-κB and Caspase-3 Expression.

    PubMed

    El-Shitany, Nagla A; El-Desoky, Karema

    2016-01-01

    The Food and Drug Administration recently warned of the fatal cardiovascular risks of azithromycin in humans. In addition, a recently published study documented azithromycin-induced cardiotoxicity in rats. This study aimed to justify the exact cardiovascular events accompanying azithromycin administration in rats, focusing on electrocardiographic, biochemical, and histopathological changes. In addition, the underlying mechanisms were studied regarding reactive oxygen species production, cytokine release, and apoptotic cell-death. Finally, the supposed protective effects of both carvedilol and vitamin C were assessed. Four groups of rats were used: (1) control, (2) azithromycin, (3) azithromycin + carvedilol, and (4) azithromycin + vitamin C. Azithromycin resulted in marked atrophy of cardiac muscle fibers and electrocardiographic segment alteration. It increased the heart rate, lactate dehydrogenase, creatine phosphokinase, malondialdehyde, nitric oxide, interleukin-1 beta (IL1-β), tumor necrosis factor alpha (TNF-α), nuclear factor kappa beta (NF-κB), and caspase-3. It decreased reduced glutathione, glutathione peroxidase, and superoxide dismutase. Carvedilol and vitamin C prevented most of the azithromycin-induced electrocardiographic and histopathological changes. Carvedilol and vitamin C decreased lactate dehydrogenase, malondialdehyde, IL1-β, TNF-α, NF-κB, and caspase-3. Both agents increased glutathione peroxidase. This study shows that both carvedilol and vitamin C protect against azithromycin-induced cardiotoxicity through antioxidant, immunomodulatory, and antiapoptotic mechanisms. PMID:27274777

  7. Vermicompost humic acids modulate the accumulation and metabolism of ROS in rice plants.

    PubMed

    García, Andrés Calderín; Santos, Leandro Azevedo; de Souza, Luiz Gilberto Ambrósio; Tavares, Orlando Carlos Huertas; Zonta, Everaldo; Gomes, Ernane Tarcisio Martins; García-Mina, José Maria; Berbara, Ricardo Luis Louro

    2016-03-15

    This work aims to determine the reactive oxygen species (ROS) accumulation, gene expression, anti-oxidant enzyme activity, and derived effects on membrane lipid peroxidation and certain stress markers (proline and malondialdehyde-MDA) in the roots of unstressed and PEG-stressed rice plants associated with vermicompost humic acid (VCHA) application. The results show that the application of VCHA to the roots of unstressed rice plants caused a slight but significant increase in root ROS accumulation and the gene expression and activity of the major anti-oxidant enzymes (superoxide dismutase and peroxidase). This action did not have negative effects on root development, and an increase in both root growth and root proliferation occurred. However, the root proline and MDA concentrations and the root permeability results indicate the development of a type of mild stress associated with VCHA application. When VCHA was applied to PEG-stressed plants, a clear alleviation of the inhibition in root development linked to PEG-mediated osmotic stress was observed. This was associated with a reduction in root ROS production and anti-oxidant enzymatic activity caused by osmotic stress. This alleviation of stress caused by VCHA was also reflected as a reduction in the PEG-mediated concentration of MDA in the root as well as root permeability. In summary, the beneficial action of VCHA on the root development of unstressed or PEG-stressed rice plants clearly involves the modulation of ROS accumulation in roots. PMID:26851887

  8. Roles for ROS and hydrogen sulfide in the longevity response to germline loss in Caenorhabditis elegans

    PubMed Central

    Wei, Yuehua; Kenyon, Cynthia

    2016-01-01

    In Caenorhabditis elegans, removing germ cells slows aging and extends life. Here we show that transcription factors that extend life and confer protection to age-related protein-aggregation toxicity are activated early in adulthood in response to a burst of reactive oxygen species (ROS) and a shift in sulfur metabolism. Germline loss triggers H2S production, mitochondrial biogenesis, and a dynamic pattern of ROS in specific somatic tissues. A cytoskeletal protein, KRI-1, plays a key role in the generation of H2S and ROS. These kri-1–dependent redox species, in turn, promote life extension by activating SKN-1/Nrf2 and the mitochondrial unfolded-protein response, respectively. Both H2S and, remarkably, kri-1–dependent ROS are required for the life extension produced by low levels of the superoxide-generator paraquat and by a mutation that inhibits respiration. Together our findings link reproductive signaling to mitochondria and define an inducible, kri-1–dependent redox-signaling module that can be invoked in different contexts to extend life and counteract proteotoxicity. PMID:27140632

  9. Roles for ROS and hydrogen sulfide in the longevity response to germline loss in Caenorhabditis elegans.

    PubMed

    Wei, Yuehua; Kenyon, Cynthia

    2016-05-17

    In Caenorhabditis elegans, removing germ cells slows aging and extends life. Here we show that transcription factors that extend life and confer protection to age-related protein-aggregation toxicity are activated early in adulthood in response to a burst of reactive oxygen species (ROS) and a shift in sulfur metabolism. Germline loss triggers H2S production, mitochondrial biogenesis, and a dynamic pattern of ROS in specific somatic tissues. A cytoskeletal protein, KRI-1, plays a key role in the generation of H2S and ROS. These kri-1-dependent redox species, in turn, promote life extension by activating SKN-1/Nrf2 and the mitochondrial unfolded-protein response, respectively. Both H2S and, remarkably, kri-1-dependent ROS are required for the life extension produced by low levels of the superoxide-generator paraquat and by a mutation that inhibits respiration. Together our findings link reproductive signaling to mitochondria and define an inducible, kri-1-dependent redox-signaling module that can be invoked in different contexts to extend life and counteract proteotoxicity. PMID:27140632

  10. ROS-mediated vascular homeostatic control of root-to-shoot soil Na delivery in Arabidopsis

    PubMed Central

    Jiang, Caifu; Belfield, Eric J; Mithani, Aziz; Visscher, Anne; Ragoussis, Jiannis; Mott, Richard; Smith, J Andrew C; Harberd, Nicholas P

    2012-01-01

    Sodium (Na) is ubiquitous in soils, and is transported to plant shoots via transpiration through xylem elements in the vascular tissue. However, excess Na is damaging. Accordingly, control of xylem-sap Na concentration is important for maintenance of shoot Na homeostasis, especially under Na stress conditions. Here we report that shoot Na homeostasis of Arabidopsis thaliana plants grown in saline soils is conferred by reactive oxygen species (ROS) regulation of xylem-sap Na concentrations. We show that lack of A. thaliana respiratory burst oxidase protein F (AtrbohF; an NADPH oxidase catalysing ROS production) causes hypersensitivity of shoots to soil salinity. Lack of AtrbohF-dependent salinity-induced vascular ROS accumulation leads to increased Na concentrations in root vasculature cells and in xylem sap, thus causing delivery of damaging amounts of Na to the shoot. We also show that the excess shoot Na delivery caused by lack of AtrbohF is dependent upon transpiration. We conclude that AtrbohF increases ROS levels in wild-type root vasculature in response to raised soil salinity, thereby limiting Na concentrations in xylem sap, and in turn protecting shoot cells from transpiration-dependent delivery of excess Na. PMID:23064146