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Sample records for acid-induced stress resistance

  1. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

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    Klingelhoeffer Christoph

    2012-05-01

    against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress.

  2. Withaferin A protects against palmitic acid-induced endothelial insulin resistance and dysfunction through suppression of oxidative stress and inflammation

    OpenAIRE

    Kalaivani Batumalaie; Muhammad Arif Amin; Dharmani Devi Murugan; Munavvar Zubaid Abdul Sattar; Nor Azizan Abdullah

    2016-01-01

    Activation of inflammatory pathways via reactive oxygen species (ROS) by free fatty acids (FFA) in obesity gives rise to insulin resistance and endothelial dysfunction. Withaferin A (WA), possesses both antioxidant and anti-inflammatory properties and therefore would be a good strategy to suppress palmitic acid (PA)-induced oxidative stress and inflammation and hence, insulin resistance and dysfunction in the endothelium. Effect of WA on PA-induced insulin resistance in human umbilical vein e...

  3. Withaferin A protects against palmitic acid-induced endothelial insulin resistance and dysfunction through suppression of oxidative stress and inflammation.

    Science.gov (United States)

    Batumalaie, Kalaivani; Amin, Muhammad Arif; Murugan, Dharmani Devi; Sattar, Munavvar Zubaid Abdul; Abdullah, Nor Azizan

    2016-01-01

    Activation of inflammatory pathways via reactive oxygen species (ROS) by free fatty acids (FFA) in obesity gives rise to insulin resistance and endothelial dysfunction. Withaferin A (WA), possesses both antioxidant and anti-inflammatory properties and therefore would be a good strategy to suppress palmitic acid (PA)-induced oxidative stress and inflammation and hence, insulin resistance and dysfunction in the endothelium. Effect of WA on PA-induced insulin resistance in human umbilical vein endothelial cells (HUVECs) was determined by evaluating insulin signaling mechanisms whilst effect of this drug on PA-induced endothelial dysfunction was determined in acetylcholine-mediated relaxation in isolated rat aortic preparations. WA significantly inhibited ROS production and inflammation induced by PA. Furthermore, WA significantly decreased TNF-α and IL-6 production in endothelial cells by specifically suppressing IKKβ/NF-κβ phosphorylation. WA inhibited inflammation-stimulated IRS-1 serine phosphorylation and improved the impaired insulin PI3-K signaling, and restored the decreased nitric oxide (NO) production triggered by PA. WA also decreased endothelin-1 and plasminogen activator inhibitor type-1 levels, and restored the impaired endothelium-mediated vasodilation in isolated aortic preparations. These findings suggest that WA inhibited both ROS production and inflammation to restore impaired insulin resistance in cultured endothelial cells and improve endothelial dysfunction in rat aortic rings. PMID:27250532

  4. Fatty acid-induced insulin resistance

    DEFF Research Database (Denmark)

    Le Marchand-Brustel, Y; Gual, P; Grémeaux, T;

    2003-01-01

    Insulin resistance, when combined with impaired insulin secretion, contributes to the development of type 2 diabetes. Insulin resistance is characterized by a decrease in the insulin effect on glucose transport in muscle and adipose tissue. Tyrosine phosphorylation of IRS-1 (insulin receptor...... substrate 1) and its binding to PI 3-kinase (phosphoinositide 3-kinase) are critical events in the insulin signalling cascade leading to insulin-stimulated glucose transport. Various studies have implicated lipids as a cause of insulin resistance in muscle. Elevated plasma fatty acid concentrations...... are associated with reduced insulin-stimulated glucose transport activity as a consequence of altered insulin signalling through PI 3-kinase. Modification of IRS-1 by serine phosphorylation could be one of the mechanisms leading to a decrease in IRS-1 tyrosine phosphorylation, PI 3-kinase activity and glucose...

  5. Ameliorative effects of polyunsaturated fatty acids against palmitic acid-induced insulin resistance in L6 skeletal muscle cells

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    Sawada Keisuke

    2012-03-01

    Full Text Available Abstract Background Fatty acid-induced insulin resistance and impaired glucose uptake activity in muscle cells are fundamental events in the development of type 2 diabetes and hyperglycemia. There is an increasing demand for compounds including drugs and functional foods that can prevent myocellular insulin resistance. Methods In this study, we established a high-throughput assay to screen for compounds that can improve myocellular insulin resistance, which was based on a previously reported non-radioisotope 2-deoxyglucose (2DG uptake assay. Insulin-resistant muscle cells were prepared by treating rat L6 skeletal muscle cells with 750 μM palmitic acid for 14 h. Using the established assay, the impacts of several fatty acids on myocellular insulin resistance were determined. Results In normal L6 cells, treatment with saturated palmitic or stearic acid alone decreased 2DG uptake, whereas unsaturated fatty acids did not. Moreover, co-treatment with oleic acid canceled the palmitic acid-induced decrease in 2DG uptake activity. Using the developed assay with palmitic acid-induced insulin-resistant L6 cells, we determined the effects of other unsaturated fatty acids. We found that arachidonic, eicosapentaenoic and docosahexaenoic acids improved palmitic acid-decreased 2DG uptake at lower concentrations than the other unsaturated fatty acids, including oleic acid, as 10 μM arachidonic acid showed similar effects to 750 μM oleic acid. Conclusions We have found that polyunsaturated fatty acids, in particular arachidonic and eicosapentaenoic acids prevent palmitic acid-induced myocellular insulin resistance.

  6. Resistance to ursodeoxycholic acid-induced growth arrest can also result in resistance to deoxycholic acid-induced apoptosis and increased tumorgenicity

    International Nuclear Information System (INIS)

    There is a large body of evidence which suggests that bile acids increase the risk of colon cancer and act as tumor promoters, however, the mechanism(s) of bile acids mediated tumorigenesis is not clear. Previously we showed that deoxycholic acid (DCA), a tumorogenic bile acid, and ursodeoxycholic acid (UDCA), a putative chemopreventive agent, exhibited distinct biological effects, yet appeared to act on some of the same signaling molecules. The present study was carried out to determine whether there is overlap in signaling pathways activated by tumorogenic bile acid DCA and chemopreventive bile acid UDCA. To determine whether there was an overlap in activation of signaling pathways by DCA and UDCA, we mutagenized HCT116 cells and then isolated cell lines resistant to UDCA induced growth arrest. These lines were then tested for their response to DCA induced apoptosis. We found that a majority of the cell lines resistant to UDCA-induced growth arrest were also resistant to DCA-induced apoptosis, implying an overlap in DCA and UDCA mediated signaling. Moreover, the cell lines which were the most resistant to DCA-induced apoptosis also exhibited a greater capacity for anchorage independent growth. We conclude that UDCA and DCA have overlapping signaling activities and that disregulation of these pathways can lead to a more advanced neoplastic phenotype

  7. Proteomic analysis of salicylic acid induced resistance to Mungbean Yellow Mosaic India Virus in Vigna mungo.

    Science.gov (United States)

    Kundu, Subrata; Chakraborty, Dipjyoti; Pal, Amita

    2011-03-01

    The role of salicylic acid (SA) in inducing resistance to MYMIV infection in Vigna mungo has been elucidated by proteomics. Twenty-nine proteins identified by MALDI-TOF/TOF, predicted to be involved in stress responses, metabolism, photosynthesis, transport and signal transduction, showed increased abundance upon SA treatment. Susceptible plants showed characteristic yellow mosaic symptoms upon MYMIV infection. A concentration dependent decrease in physiological symptoms associated with MYMIV was observed upon exogenous SA treatment prior to viral inoculation; and no visible symptom was observed at 100 μM SA. SA treatment stimulated SOD and GPX activity and inhibited CAT activity thus preventing ROS mediated damage. Significant increase in chlorophyll, protein, carbohydrate, phenolic content and H(2)O(2) were observed. Involvement of calmodulin for transmission of defense signal by SA is suggested. A metabolic reprogramming leading to enhanced synthesis of proteins involved in primary and secondary metabolisms is necessary for SA mediated resistance to MYMIV. Identification of proteins showing increased abundance, involved in photosynthetic process is a significant finding which restores virus-induced degradation of the photosynthetic apparatus and provides enhanced metabolites required for repartition of resources towards defense.

  8. Saturated Fatty Acid Induces Insulin Resistance Partially Through Nucleotide-binding Oligomerization Domain 1 Signaling Pathway in Adipocytes

    Institute of Scientific and Technical Information of China (English)

    Yi-jun Zhou; Yin-si Tang; Yu-ling Song; Ai Li; Hui Zhou; Yan Li

    2013-01-01

    Objective To investigate the potential role of nucleotide-binding oligomerization domain 1 (NOD1), a component of the innate immune system, in mediating lipid-induced insulin resistance in adipocytes. Methods Adipocytes from Toll-like receptor 4 deficiency mice were used for stimulation experiments. The effect of oleate/palmitate mixture on nuclear factor-κB (NF-κB) activation was analyzed by reporter plasmid assay. The release of proinflammatory chemokine/cytokines production was determined by using real-time PCR. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[3H] glucose uptake assay. Chemokine/cytokine expression and glucose uptake in adipocytes transfected with small interfering RNA (siRNA) targeting NOD1 upon fatty acids treatment were analyzed. Results Oleate/palmitate mixture activated the NF-κB pathway and induced interleukin-6, tumor necrosis factor-α, and monocyte chemoattractant protein-1 mRNA expressions in adipocytes from mice deficient in Toll-like receptor 4, and these effects were blocked by siRNA targeting NOD1. Furthermore, saturated fatty acids decreased the ability of insulin-stimulated glucose uptake. Importantly, siRNA targeting NOD1 partially reversed saturated fatty acid-induced suppression of insulin-induced glucose uptake. Conclusion NOD1 might play an important role in saturated fatty acid-induced insulin resistance in adipocytes, suggesting a mechanism by which reduced NOD1 activity confers beneficial effects on insulin action.

  9. DL-β-aminobutyric acid-induced resistance in soybean against Aphis glycines Matsumura (Hemiptera: Aphididae.

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    Yunpeng Zhong

    Full Text Available Priming can improve plant innate capability to deal with the stresses caused by both biotic and abiotic factors. In this study, the effect of DL-β-amino-n-butyric acid (BABA against Aphis glycines Matsumura, the soybean aphid (SA was evaluated. We found that 25 mM BABA as a root drench had minimal adverse impact on plant growth and also efficiently protected soybean from SA infestation. In both choice and non-choice tests, SA number was significantly decreased to a low level in soybean seedlings drenched with 25 mM BABA compared to the control counterparts. BABA treatment resulted in a significant increase in the activities of several defense enzymes, such as phenylalanine ammonia-lyase (PAL, peroxidase (POX, polyphenol oxidase (PPO, chitinase (CHI, and β-1, 3-glucanase (GLU in soybean seedlings attacked by aphid. Meanwhile, the induction of 15 defense-related genes by aphid, such as AOS, CHS, MMP2, NPR1-1, NPR1-2, and PR genes, were significantly augmented in BABA-treated soybean seedlings. Our study suggest that BABA application is a promising way to enhance soybean resistance against SA.

  10. Berberine reverses free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM:To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-LI adipocytes.METHODS:The model of insulin resistance in 3T3-L1 adipocytes was established by adding palmic acid (0.5 mmol/L) to the culture medium.Berberine treatment was performed at the same time.Glucose uptake rate was determined by the 2-deoxy-[3H]-Dglucose method.The levels of IkB kinase beta (IKKβ)Ser181 phosphorylation,insulin receptor substrate1(IRS-1) Ser307 phosphorylation,expression of IKKβ,IRS-1,nuclear transcription factor kappaB p65 (NF-κB p65),phosphatidylinositol-3-kinase p85(PI-3K p85) and glucose transporter 4 (GLUT4) proteins were detected by Western blotting.The distribution of NF-κB p65 proteins inside the adipocytes was observed through confocal laser scanning microscopy(CLSM).RESULTS:After the intervention of palmic acid for 24 h,the insulin-stimulated glucose transport in 3T3-L1 adipocytes was inhibited by 67%.Meanwhile,the expression of IRS-1 and PI-3K p85 protein was reduced,while the levels of IKKβ Ser181 and IRS-1 Ser307 phosphorylation,and nuclear translocation of NF-κB p65 protein were increased.However,the above indexes,which indicated the existence of insulin resistance,were reversed by berberine although the expression of GLUT4,IKKβ and total NF-κB p65 protein were not changed during this study.CONCLUSION:Insulin resistance induced by FFAs in 3T3-L1 adipocytes can be improved by berberine.Berberine reversed free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ.

  11. High Uric Acid Induces Insulin Resistance in Cardiomyocytes In Vitro and In Vivo.

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    Li Zhi

    Full Text Available Clinical studies have shown hyperuricemia strongly associated with insulin resistance as well as cardiovascular disease. Direct evidence of how high uric acid (HUA affects insulin resistance in cardiomyocytes, but the pathological mechanism of HUA associated with cardiovascular disease remains to be clarified. We aimed to examine the effect of HUA on insulin sensitivity in cardiomyocytes and on insulin resistance in hyperuricemic mouse model. We exposed primary cardiomyocytes and a rat cardiomyocyte cell line, H9c2 cardiomyocytes, to HUA, then quantified glucose uptake with a fluorescent glucose analog, 2-NBDG, after insulin challenge and detected reactive oxygen species (ROS production. Western blot analysis was used to examine the levels of insulin receptor (IR, phosphorylated insulin receptor substrate 1 (IRS1, Ser307 and phospho-Akt (Ser473. We monitored the impact of HUA on insulin resistance, insulin signaling and IR, phospho-IRS1 (Ser307 and phospho-Akt levels in myocardial tissue of an acute hyperuricemia mouse model established by potassium oxonate treatment. HUA inhibited insulin-induced glucose uptake in H9c2 and primary cardiomyocytes. It increased ROS production; pretreatment with N-acetyl-L-cysteine (NAC, a ROS scavenger, reversed HUA-inhibited glucose uptake induced by insulin. HUA exposure directly increased the phospho-IRS1 (Ser307 response to insulin and inhibited that of phospho-Akt in H9C2 cardiomyocytes, which was blocked by NAC. Furthermore, the acute hyperuricemic mice model showed impaired glucose tolerance and insulin tolerance accompanied by increased phospho-IRS1 (Ser307 and inhibited phospho-Akt response to insulin in myocardial tissues. HUA inhibited insulin signaling and induced insulin resistance in cardiomyocytes in vitro and in vivo, which is a novel potential mechanism of hyperuricemic-related cardiovascular disease.

  12. Salicylic acid induces differential antioxidant response in spring maize under high temperature stress.

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    Khanna, Palak; Kaur, Kamaljit; Gupta, Anil K

    2016-06-01

    High temperature is one of the important stress factors that affect crops in tropical countries. Plants do evolve or adopt different mechanisms to overcome such stress for survival. It is an interesting subject and has attracted many researchers to work upon. Here, we studied the effect of salicylic acid (SA) on seedling growth and antioxidative defense system in two spring maize (Zea mays L.) genotypes viz., CML-32 (relatively heat tolerant) and LM-11 (relatively heat susceptible), under high temperature stress. High temperature induced greater reduction in dry biomass of LM-1 1 seedlings as compared to those of CML-32. There was a parallel increase in ascorbate peroxidase and glutathione reductase activities in the roots of CML-32 seedlings. However, the activities of catalase and superoxide dismutase decreased and the contents of H202, proline and malonaldialdehyde (MDA) increased in seedlings of both the genotypes. Application of SA (400 µM) led to increased dry biomass in heat stressed CML-32 seedlings. It improved the efficiency of Halliwell-Asada pathway in roots of CML-32 seedlings as was evidenced by the enhanced ascorbate peroxidase and glutathione reductase activities. The activities of catalase and superoxide dismutase increased in both the tissues of LM-11 seedlings, whereas in CML-32, it was only in shoots, after SA application. Peroxidase activity increased in SA treated seedlings of both the genotypes, though the increase was comparatively higher in CML-32. The contents of H₂O₂ and MDA decreased and that of proline increased in SA treated seedlings of both the genotypes, under stress conditions. It may be concluded that SA induced differential antioxidant response by upregulating Halliwell-Asada pathway in roots and attaining high POX activity in both the tissues of CML-32 seedlings, under high temperature stress. PMID:27468465

  13. Fusaric acid induces mitochondrial stress in human hepatocellular carcinoma (HepG2) cells.

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    Sheik Abdul, Naeem; Nagiah, Savania; Chuturgoon, Anil A

    2016-09-01

    Fusarium spp are common contaminants of maize and produce many mycotoxins, including the fusariotoxin fusaric acid (FA). FA is a niacin related compound, chelator of divalent cations, and mediates toxicity via oxidative stress and possible mitochondrial dysregulation. Sirtuin 3 (SIRT3) is a stress response deacetylase that maintains proper mitochondrial function. We investigated the effect of FA on SIRT3 and oxidative and mitochondrial stress pathways in the hepatocellular carcinoma (HepG2) cell line. We determined FA toxicity (24 h incubation; IC50 = 104 μg/ml) on mitochondrial output, cellular and mitochondrial stress responses, mitochondrial biogenesis and markers of cell death using spectrophotometry, luminometry, qPCR and western blots. FA caused a dose dependent decrease in metabolic activity along with significant depletion of intracellular ATP. FA induced a significant increase in lipid peroxidation, despite up-regulation of the antioxidant transcription factor, Nrf2. FA significantly decreased expression of SIRT3 mRNA with a concomitant decrease in protein expression. Lon protease was also significantly down-regulated. FA induced aberrant mitochondrial biogenesis as evidenced by significantly decreased protein expressions of: PGC-1α, p-CREB, NRF1 and HSP70. Finally, FA activated apoptosis as noted by the significantly increased activity of caspases 3/7 and also induced cellular necrosis. This study provides insight into the molecular mechanisms of FA (a neglected mycotoxin) induced hepatotoxicity. PMID:27390038

  14. Salubrinal, ER stress inhibitor, attenuates kainic acid-induced hippocampal cell death.

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    Kim, Jung Soo; Heo, Rok Won; Kim, Hwajin; Yi, Chin-Ok; Shin, Hyun Joo; Han, Jong Woo; Roh, Gu Seob

    2014-10-01

    Kainic acid (KA)-induced neuronal death is closely linked to endoplasmic reticulum (ER) and mitochondrial dysfunction. Parkin is an ubiquitin E3 ligase that mediates the ubiquitination of the Bcl-2 family of proteins and its mutations are associated with neuronal apoptosis in neurodegenerative diseases. We investigated the effect of salubrinal, an ER stress inhibitor, on the regulation of ER stress and mitochondrial apoptosis induced by KA, in particular, by controlling parkin expression. We showed that salubrinal significantly reduced seizure activity and increased survival rates of mice with KA-induced seizures. We found that salubrinal protected neurons against apoptotic death by reducing expression of mitochondrial apoptotic factors and elF2α-ATF4-CHOP signaling proteins. Interestingly, we showed that salubrinal decreased the KA-induced parkin expression and inhibited parkin translocation to mitochondria, which suggests that parkin may regulate a cross-talk between ER and mitochondria. Collectively, inhibition of ER stress attenuates mitochondrial apoptotic and ER stress pathways and controls parkin-mediated neuronal death following KA-induced seizures. PMID:24728926

  15. Pseudomonas putida response in membrane bioreactors under salicylic acid-induced stress conditions

    International Nuclear Information System (INIS)

    Highlights: • MBR under feed-induced stress conditions: starvation and changing feeding conditions. • High capacity of MBR to withstand high variations in feed loads. • Slow biofilm formation under starvation conditions during the first days. • Observed growth of P. putida for substrate to microorganism ratio higher than 0.6 g/g. • Maximum specific growth rate and growth yield values of around 37.5 h−1 and 0.5 g/g. - Abstract: Starvation and changing feeding conditions are frequently characteristics of wastewater treatment plants. They are typical causes of unsteady-state operation of biological systems and provoke cellular stress. The response of a membrane bioreactor functioning under feed-induced stress conditions is studied here. In order to simplify and considerably amplify the response to stress and to obtain a reference model, a pure culture of Pseudomonas putida was selected instead of an activated sludge and a sole substrate (salicylic acid) was employed. The system degraded salicylic acid at 100–1100 mg/L with a high level of efficiency, showed rapid acclimation without substrate or product inhibition phenomena and good stability in response to unsteady states caused by feed variations. Under starvation conditions, specific degradation rates of around 15 mg/g h were achieved during the adaptation of the biomass to the new conditions and no biofilm formation was observed during the first days of experimentation using an initial substrate to microorganisms ratio lower than 0.1. When substrate was added to the reactor as pulses resulting in rapidly changing concentrations, P. putida growth was observed only for substrate to microorganism ratios higher than 0.6, with a maximum YX/S of 0.5 g/g. Biofilm development under changing feeding conditions was fast, biomass detachment only being significant for biomass concentrations on the membrane surface that were higher than 16 g/m2

  16. Pseudomonas putida response in membrane bioreactors under salicylic acid-induced stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Sergio; Rosas, Irene; González, Elena; Gutierrez-Lavin, Antonio; Diaz, Mario, E-mail: mariodiaz@uniovi.es

    2014-02-01

    Highlights: • MBR under feed-induced stress conditions: starvation and changing feeding conditions. • High capacity of MBR to withstand high variations in feed loads. • Slow biofilm formation under starvation conditions during the first days. • Observed growth of P. putida for substrate to microorganism ratio higher than 0.6 g/g. • Maximum specific growth rate and growth yield values of around 37.5 h{sup −1} and 0.5 g/g. - Abstract: Starvation and changing feeding conditions are frequently characteristics of wastewater treatment plants. They are typical causes of unsteady-state operation of biological systems and provoke cellular stress. The response of a membrane bioreactor functioning under feed-induced stress conditions is studied here. In order to simplify and considerably amplify the response to stress and to obtain a reference model, a pure culture of Pseudomonas putida was selected instead of an activated sludge and a sole substrate (salicylic acid) was employed. The system degraded salicylic acid at 100–1100 mg/L with a high level of efficiency, showed rapid acclimation without substrate or product inhibition phenomena and good stability in response to unsteady states caused by feed variations. Under starvation conditions, specific degradation rates of around 15 mg/g h were achieved during the adaptation of the biomass to the new conditions and no biofilm formation was observed during the first days of experimentation using an initial substrate to microorganisms ratio lower than 0.1. When substrate was added to the reactor as pulses resulting in rapidly changing concentrations, P. putida growth was observed only for substrate to microorganism ratios higher than 0.6, with a maximum Y{sub X/S} of 0.5 g/g. Biofilm development under changing feeding conditions was fast, biomass detachment only being significant for biomass concentrations on the membrane surface that were higher than 16 g/m{sup 2}.

  17. Pseudomonas putida response in membrane bioreactors under salicylic acid-induced stress conditions.

    Science.gov (United States)

    Collado, Sergio; Rosas, Irene; González, Elena; Gutierrez-Lavin, Antonio; Diaz, Mario

    2014-02-28

    Starvation and changing feeding conditions are frequently characteristics of wastewater treatment plants. They are typical causes of unsteady-state operation of biological systems and provoke cellular stress. The response of a membrane bioreactor functioning under feed-induced stress conditions is studied here. In order to simplify and considerably amplify the response to stress and to obtain a reference model, a pure culture of Pseudomonas putida was selected instead of an activated sludge and a sole substrate (salicylic acid) was employed. The system degraded salicylic acid at 100-1100mg/L with a high level of efficiency, showed rapid acclimation without substrate or product inhibition phenomena and good stability in response to unsteady states caused by feed variations. Under starvation conditions, specific degradation rates of around 15mg/gh were achieved during the adaptation of the biomass to the new conditions and no biofilm formation was observed during the first days of experimentation using an initial substrate to microorganisms ratio lower than 0.1. When substrate was added to the reactor as pulses resulting in rapidly changing concentrations, P. putida growth was observed only for substrate to microorganism ratios higher than 0.6, with a maximum YX/S of 0.5g/g. Biofilm development under changing feeding conditions was fast, biomass detachment only being significant for biomass concentrations on the membrane surface that were higher than 16g/m(2).

  18. Antagonistic rhizobacteria and jasmonic acid induce resistance against tomato bacterial spot

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    Hélvio Gledson Maciel Ferraz

    2015-12-01

    Full Text Available AbstractTomato bacterial spot on tomato may be caused by four species of Xanthomonas and among them X. gardneri(Xg is the most destructive one, especially in areas irrigated using a center pivot system in Minas Gerais state and the midwest region of Brazil. Due to the ineffectiveness of chemical control and the lack of cultivars with high levels of genetic resistance, this study investigated the potential of three antagonists (Streptomyces setonii (UFV618, Bacillus cereus (UFV592 and Serratia marcescens (UFV252, and the hormone jasmonic acid (JA as a positive control, to reduce bacterial spot symptoms and to potentiate defense enzymes in the leaves of tomato plants infected by Xg. Tomato seeds were microbiolized with each antagonist, and the soil was drenched with these bacteria. The plants were sprayed with JA 48 h before Xginoculation. The final average severity on the tomato plants was reduced by 29.44, 59.26 and 61.33% in the UFV592, UFV618 and JA treatments, respectively. The UFV618 antagonist was as effective as JA in reducing bacterial spot symptoms on tomatoes, which can be explained by the greater activities of defense enzymes that are commonly involved in host resistance against bacterial diseases. These results suggest that JA and the UFV618 antagonist can be used in the integrated management of bacterial spot on tomatoes.

  19. Jasmonic acid induced resistance in grapevines to a root and leaf feeder.

    Science.gov (United States)

    Omer, A D; Thaler, J S; Granett, J; Karban, R

    2000-06-01

    We investigated the effects of induced resistance to the folivore Pacific spider mite, Tetranychus pacificus McGregor (Acari: Tetranychidae), as well as the root-feeding grape phylloxera Daktulosphaira vitifoliae (Fitch) (Homoptera: Phylloxeridae) in grapevines using exogenous applications of the natural plant inducer, jasmonic acid. Foliar jasmonic acid application at concentrations that caused no phytotoxicity significantly reduced the performance of both herbivores. There were less than half as many eggs produced by spider mites feeding on the induced leaves compared with control grapevine leaves. Induction reduced the numbers of phylloxera eggs and nymphal instars by approximately threefold and twofold, respectively, on induced compared with control grapevine roots. The negative demographic effects of jasmonic acid application appeared to be caused by changes in fecundity for the Pacific spider mite, and possibly changes in development rate and fecundity for grape phylloxera. PMID:10902339

  20. Salidroside protects against kainic acid-induced status epilepticus via suppressing oxidative stress.

    Science.gov (United States)

    Si, Pei-Pei; Zhen, Jun-Li; Cai, Yun-Lei; Wang, Wen-Jing; Wang, Wei-Ping

    2016-04-01

    There are numerous mechanisms by which the brain generates seizures. It is well known that oxidative stress plays a pivotal role in status epilepticus (SE). Salidroside (SDS) extracted from Rhodiola rosea L. shows multiple bioactive properties, such as neuroprotection and antioxidant activity in vitro and in vivo. This study explored the role of SDS in kainic acid (KA)-induced SE and investigated the underlying mechanism. Latency to SE increased in the SDS-pretreated mice compared to the KA group, while the percentage of incidence of SE was significantly reduced. These results suggested that pretreatment with SDS not only delayed SE, but it also decreased the incidence of SE induced by KA. KA increased MDA level and reduced the production of SOD and GSH at multiple timepoints after KA administration. SDS inhibited the change of MDA, SOD and GSH induced by KA prior to SE onset, indicating that SDS protects against KA-induced SE via suppressing oxidative stress. Based on these results, we investigated the possible molecular mechanism of SDS. Pretreatment with SDS reversed the KA-induced decrease in AMP-activated protein kinase (AMPK); increased the sirtuin 1 (SIRT1) deacetylase activity in KA-treated mice, which had no demonstrable effect on SIRT1 mRNA and protein; and suppressed the KA-induced increase in Ace-FoxO1. These results showed that AMPK/SIRT1/FoxO1 signaling is possibly the molecular mechanism of neuroprotection by SDS.

  1. Salicylic acid induced physiological and biochemical changes in wheat under drought stress conditions

    International Nuclear Information System (INIS)

    Experiment for finding the effect of pre-soaking of wheat seeds varieties, viz Wafaq-2001 and Punjab-96, in salicylic acid (SA) solution on the drought tolerance of wheat, revealed increase in the total biomass and grain yield per plant as well as in spikes per plant, 100 seed weight, proline, total soluble sugars, membrane stability index (MSI), superoxide dismutase (SOD) and ascorbate peroxidase (APOX) activity in both the tested varieties. The yield increase in drought tolerant variety Wafaq-2001 was more as compared to drought sensitive Punjab-96. Results signify the role of SA in regulating the drought response of wheat and that SA could be seed primed and used as a potential growth regulator under drought stress conditions. (author)

  2. Nitric Oxide Mediates 5-Aminolevulinic Acid-Induced Antioxidant Defense in Leaves of Elymus nutans Griseb. Exposed to Chilling Stress.

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    Juanjuan Fu

    Full Text Available Nitric oxide (NO and 5-aminolevulinic acid (ALA are both extremely important signalling molecules employed by plants to control many aspects of physiology. In the present study, the role of NO in ALA-induced antioxidant defense in leaves of two sources of Elymus nutans Griseb. (Damxung, DX and Zhengdao, ZD was investigated. Chilling stress enhanced electrolyte leakage, accumulation of malondialdehyde (MDA, hydrogen peroxide (H2O2 and superoxide radical in two E. nutans, which were substantially alleviated by exogenous ALA and NO application. Pretreatment with NO scavenger PTIO or NOS inhibitor L-NNA alone and in combination with ALA induced enhancements in electrolyte leakage and the accumulation of MDA, H2O2 and superoxide radical in leaves of DX and ZD exposed to chilling stress, indicating that the inhibition of NO biosynthesis reduced the chilling resistance of E. nutans and the ALA-enhanced chilling resistance. Further analyses showed that ALA and NO enhanced antioxidant defense and activated plasma membrane (PM H+-ATPase and decreased the accumulation of ROS induced by chilling stress. A pronounced increase in nitric oxide synthase (NOS activity and NO release by exogenous ALA treatment was found in chilling-resistant DX plants exposed to chilling stress, while only a little increase was observed in chilling-sensitive ZD. Furthermore, inhibition of NO accumulation by PTIO or L-NNA blocked the protective effect of exogenous ALA, while both exogenous NO treatment and inhibition of endogenous NO accumulation did not induce ALA production. These results suggested that NO might be a downstream signal mediating ALA-induced chilling resistance in E. nutans.

  3. Interleukin-6 deficiency reduces the brain inflammatory response and increases oxidative stress and neurodegeneration after kainic acid-induced seizures

    DEFF Research Database (Denmark)

    Penkowa, M; Molinero, A; Carrasco, J;

    2001-01-01

    The role of interleukin-6 in hippocampal tissue damage after injection with kainic acid, a rigid glutamate analogue inducing epileptic seizures, has been studied by means of interleukin-6 null mice. At 35mg/kg, kainic acid induced convulsions in both control (75%) and interleukin-6 null (100%) mi...

  4. Glycine betaine and salicylic acid induced modification in productivity of two different cultivars of wheat grown under water stress

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    Heshmat S. Aldesuquy

    2012-05-01

    Full Text Available A pot experiment was conducted to evaluate the beneficial effect of foliar application of glycine betaine (10mM, grain presoaking in salicylic acid (0.05 M and their interaction on drought tolerance of two wheat (Triticum aestivum L. cultivars (sensitive, Sakha 94 and resistant, Sakha 93. Water stress decreased wheat yield components (spike length, number of spikelets / main spike, 100 kernel weight, grain number / spike, grain yield / spike, grain yield / plant, straw yield / plant, crop yield / plant, harvest, mobilization and crop indices and the biochemical aspects of grains(grain biomass, carbohydrates, total protein, total phosphorus, ions content and amino acids in both wheat cultivars. The applied chemicals appeared to alleviate the negative effects of water stress on wheat productivity (particularly the sensitive one and the biochemical aspects of yielded grains. The effect was more pronounced with GB+SA treatment. This improvement would result from the repairing effect of the provided chemicals on growth and metabolism of wheat plants grown under water deficit condition. In response to the applied water stress and the used chemicals, the grain yield of the sensitive and resistant wheat cultivars was strongly correlated with all the estimated yield components (shoot length, spike length, plant height, main spike weight, number of spikelets per main spike, 100 kernel weight, grain number per spike, grain weight per plant, straw weight per plant, crop yield per plant, harvest, mobilization and crop indices.

  5. The role of amino acid-induced mammalian target of rapamycin complex 1(mTORC1) signaling in insulin resistance.

    Science.gov (United States)

    Yoon, Mee-Sup; Choi, Cheol Soo

    2016-01-01

    Mammalian target of rapamycin (mTOR) controls cell growth and metabolism in response to nutrients, energy, and growth factors. Recent findings have placed the lysosome at the core of mTOR complex 1 (mTORC1) regulation by amino acids. Two parallel pathways, Rag GTPase-Ragulator and Vps34-phospholipase D1 (PLD1), regulate mTOR activation on the lysosome. This review describes the recent advances in understanding amino acid-induced mTOR signaling with a particular focus on the role of mTOR in insulin resistance. PMID:27534530

  6. Free fatty acid-induced hepatic insulin resistance is attenuated following lifestyle intervention in obese individuals with impaired glucose tolerance

    DEFF Research Database (Denmark)

    Haus, Jacob M; Solomon, Thomas; Marchetti, Christine M;

    2010-01-01

    The objective of the study was to examine the effects of an exercise/diet lifestyle intervention on free fatty acid (FFA)-induced hepatic insulin resistance in obese humans.......The objective of the study was to examine the effects of an exercise/diet lifestyle intervention on free fatty acid (FFA)-induced hepatic insulin resistance in obese humans....

  7. Long-term fatty liver-induced insulin resistance in orotic acid-induced nonalcoholic fatty liver rats.

    Science.gov (United States)

    Han, Xiuqing; Liu, Chunhua; Xue, Yong; Wang, Jingfeng; Xue, Changhu; Yanagita, Teruyoshi; Gao, Xiang; Wang, Yuming

    2016-01-01

    We investigated whether fatty liver preceded insulin resistance or vice versa using a long-term orotic acid (OA)-induced nonalcoholic fatty liver disease (NAFLD) model without the confounding effects of obesity and hyperlipidemia and explored the role of the liver in insulin resistance. Male Wistar rats were fed with or without OA supplementation for 30, 60, and 90 days. The NAFLD group showed increased liver lipid at 30, 60, and 90 days; glucose intolerance was noted at 60 and 90 days. Furthermore, partial liver proteins and gene expressions related to upstream signaling of insulin were decreased. However, the liver glycogen content was elevated, and gluconeogenesis genes expressions were obviously decreased at 90 days. The occurrence of fatty liver preceded insulin resistance in OA-induced NAFLD without the interference of obesity and hyperlipidemia, and hepatic insulin resistance may not play a conclusive role in insulin resistance in this model. PMID:26775542

  8. Albumin-bound fatty acids induce mitochondrial oxidant stress and impair antioxidant responses in proximal tubular cells

    NARCIS (Netherlands)

    Ishola, D. A.; Post, J. A.; van Timmeren, M. M.; Bakker, S. J. L.; Goldschmeding, R.; Koomans, H. A.; Braam, B.; Joles, J. A.

    2006-01-01

    Albumin induces oxidative stress and cytokine production in proximal tubular cells (PTECs). Albumin-bound fatty acids (FAs) enhance tubulopathic effects of albumin in vivo. We proposed that FA aggravation of albumin-induced oxidative stress in PTECs might be involved. We hypothesized that mitochondr

  9. Postharvest Treatment with β-Aminobutyric Acid Induces Resistance Against Dry Rot Caused by Fusarium sulphureum in Potato Tuber

    Institute of Scientific and Technical Information of China (English)

    YIN Yan; LI Yong-cai; BI Yang; CHEN Song-jiang; LI Ying-chao; YUAN Li; WANG Yi; WANG Di

    2010-01-01

    The effectiveness of postharvest β-aminobutyric acid(BABA)treatment was studied for inducing resistance against dry rot caused by Fusarium sulphureum in tubers and slices of two potato cultivars(resistant cultivar Shepody and susceptible cultivar Xindaping).The results showed that BABA at 100 mmol L-1 significantly reduced lesion diameter in inoculated both tubers and slices.The chemical at 100 mmol L-1 showed an effective reduction in infection ability of F.sulphureum inoculated 48 and 72 h after treatment in slices of resistant cultivar,and 72 and 96 h in susceptible ones.BABA increased the activitives of peroxidase(POD),polyphenoloxidase(PPO)and phenylalanine ammonialyase(PAL),and accumulated the contents of lignin,flavonoids and phenolics in slices.The resistant cultivar had a stronger resistant response than the susceptible one.These findings suggest that the BABA treatment can induce the resistance in potato tubers,however,the inducing degree depends on the original level of resistance present in each cultivar.

  10. Genetic modification of alternative respiration in Nicotiana benthamiana affects basal and salicylic acid-induced resistance to potato virus X

    Directory of Open Access Journals (Sweden)

    Verchot-Lubicz Jeanmarie

    2011-02-01

    Full Text Available Abstract Background Salicylic acid (SA regulates multiple anti-viral mechanisms, including mechanism(s that may be negatively regulated by the mitochondrial enzyme, alternative oxidase (AOX, the sole component of the alternative respiratory pathway. However, studies of this mechanism can be confounded by SA-mediated induction of RNA-dependent RNA polymerase 1, a component of the antiviral RNA silencing pathway. We made transgenic Nicotiana benthamiana plants in which alternative respiratory pathway capacity was either increased by constitutive expression of AOX, or decreased by expression of a dominant-negative mutant protein (AOX-E. N. benthamiana was used because it is a natural mutant that does not express a functional RNA-dependent RNA polymerase 1. Results Antimycin A (an alternative respiratory pathway inducer and also an inducer of resistance to viruses and SA triggered resistance to tobacco mosaic virus (TMV. Resistance to TMV induced by antimycin A, but not by SA, was inhibited in Aox transgenic plants while SA-induced resistance to this virus appeared to be stronger in Aox-E transgenic plants. These effects, which were limited to directly inoculated leaves, were not affected by the presence or absence of a transgene constitutively expressing a functional RNA-dependent RNA polymerase (MtRDR1. Unexpectedly, Aox-transgenic plants infected with potato virus X (PVX showed markedly increased susceptibility to systemic disease induction and virus accumulation in inoculated and systemically infected leaves. SA-induced resistance to PVX was compromised in Aox-transgenic plants but plants expressing AOX-E exhibited enhanced SA-induced resistance to this virus. Conclusions We conclude that AOX-regulated mechanisms not only play a role in SA-induced resistance but also make an important contribution to basal resistance against certain viruses such as PVX.

  11. Involvement of ethylene in gibberellic acid-induced sulfur assimilation, photosynthetic responses, and alleviation of cadmium stress in mustard.

    Science.gov (United States)

    Masood, Asim; Khan, M Iqbal R; Fatma, Mehar; Asgher, Mohd; Per, Tasir S; Khan, Nafees A

    2016-07-01

    The role of gibberellic acid (GA) or sulfur (S) in stimulation of photosynthesis is known. However, information on the involvement of ethylene in GA-induced photosynthetic responses and cadmium (Cd) tolerance is lacking. This work shows that ethylene is involved in S-assimilation, photosynthetic responses and alleviation of Cd stress by GA in mustard (Brassica juncea L.). Plants grown with 200 mg Cd kg(-1) soil were less responsive to ethylene despite high ethylene evolution and showed photosynthetic inhibition. Plants receiving 10 μM GA spraying plus 100 mg S kg(-1) soil supplementation exhibited increased S-assimilation and photosynthetic responses under Cd stress. Application of GA plus S decreased oxidative stress of plants grown with Cd and limited stress ethylene formation to the range suitable for promoting sulfur use efficiency (SUE), glutathione (GSH) production and photosynthesis. The role of ethylene in GA-induced S-assimilation and reversal of photosynthetic inhibition by Cd was substantiated by inhibiting ethylene biosynthesis with the use of aminoethoxyvinylglycine (AVG). The suppression of S-assimilation and photosynthetic responses by inhibiting ethylene in GA plus S treated plants under Cd stress indicated the involvement of ethylene in GA-induced S-assimilation and Cd stress alleviation. The outcome of the study is important to unravel the interaction between GA and ethylene and their role in Cd tolerance in plants. PMID:26998941

  12. Isolation of an osmotic stress- and abscisic acid-induced gene encoding an acidic endochitinase from Lycopersicon chilense.

    Science.gov (United States)

    Chen, R D; Yu, L X; Greer, A F; Cheriti, H; Tabaeizadeh, Z

    1994-10-28

    We have identified one osmotic stress- and abscisic acid-responsive member of the endochitinase (EC 3.2.1.14) gene family from leaves of drought-stressed Lycopersicon chilense plants, a natural inhabitant of extremely arid regions in South America. The 966-bp full-length cDNA (designated pcht28) encodes an acidic chitinase precursor with an amino-terminal signal peptide. The mature protein is predicted to have 229 amino acid residues with a relative molecular mass of 24,943 and pI value of 6.2. Sequence analysis revealed that pcht28 has a high degree of homology with class II chitinases (EC 3.2.1.14) from tomato and tobacco. Expression of the pcht28 protein in Escherichia coli verified that it is indeed a chitinase. Northern blot analysis indicated that this gene has evolved a different pattern of expression from that of other family members reported thus far. It is highly induced by both osmotic stress and the plant hormone abscisic acid. Southern blot analysis of genomic DNA suggested that the pcht28-related genes may form a small multigene family in this species. The efficiency of induction of the gene by drought stress, in leaves and stems, is significantly higher in L. chilense than in the cultivated tomato. It is speculated that, besides its general defensive function, the pcht28-encoded chitinase may play a particular role in plant development or in protecting plants from pathogen attack during water stress. PMID:7816027

  13. Endoplasmic reticulum stress involved in high-fat diet and palmitic acid-induced vascular damages and fenofibrate intervention

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yunxia, E-mail: wwwdluyx@sina.com [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); The Comprehensive Laboratory, Anhui Medical University, Hefei, Anhui 230032 (China); Cheng, Jingjing [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); Chen, Li [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); Department of Medical Laboratory, Anhui Provincial Hospital, Hefei, Anhui 230001 (China); Li, Chaofei; Chen, Guanjun [Department of Biochemistry and Molecular Biology, Anhui Medical University, Hefei, Anhui 230032 (China); Gui, Li [The Comprehensive Laboratory, Anhui Medical University, Hefei, Anhui 230032 (China); Shen, Bing [Department of Physiology, Anhui Medical University, Hefei, Anhui 230032 (China); Zhang, Qiu [Department of Endocrinology, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022 (China)

    2015-02-27

    Fenofibrate (FF) is widely used to lower blood lipids in clinical practice, but whether its protective effect on endothelium-dependent vasodilatation (EDV) in thoracic aorta is related with endoplasmic reticulum (ER) stress remains unknown. In this study, female Sprauge Dawley rats were divided into standard chow diets (SCD), high-fat diets (HFD) and HFD plus FF treatment group (HFD + FF) randomly. The rats of latter two groups were given HFD feeding for 5 months, then HFD + FF rats were treated with FF (30 mg/kg, once daily) via gavage for another 2 months. The pathological and tensional changes, protein expression of eNOS, and ER stress related genes in thoracic aorta were measured. Then impacts of palmitic acid (PA) and FF on EDV of thoracic aorta from normal female SD rats were observed. Ultimately the expression of ER stress related genes were assessed in primary mouse aortic endothelial cells (MAEC) treated by fenofibric acid (FA) and PA. We found that FF treatment improved serum lipid levels and pathological changes in thoracic aorta, accompanied with decreased ER stress and increased phosphorylation of eNOS. FF pretreatment also improved EDV impaired by different concentrations of PA treatment. The dose- and time-dependent inhibition of cell proliferation by PA were inverted by FA pretreatment. Phosphorylation of eNOS and expression of ER stress related genes were all inverted by FA pretreatment in PA-treated MAEC. Our findings show that fenofibrate recovers damaged EDV by chronic HFD feeding and acute stimulation of PA, this effect is related with decreased ER stress and increased phosphorylation of eNOS. - Highlights: • Fenofibrate treatment improved pathological changes in thoracic aorta by chronic high-fat-diet feeding. • Fenofibrate pretreatment improved endothelium-dependent vasodilation impaired by different concentrations of palmitic acid. • The inhibition of proliferation in endothelial cells by palmitic acid were inverted by fenofibric

  14. Endoplasmic reticulum stress involved in high-fat diet and palmitic acid-induced vascular damages and fenofibrate intervention

    International Nuclear Information System (INIS)

    Fenofibrate (FF) is widely used to lower blood lipids in clinical practice, but whether its protective effect on endothelium-dependent vasodilatation (EDV) in thoracic aorta is related with endoplasmic reticulum (ER) stress remains unknown. In this study, female Sprauge Dawley rats were divided into standard chow diets (SCD), high-fat diets (HFD) and HFD plus FF treatment group (HFD + FF) randomly. The rats of latter two groups were given HFD feeding for 5 months, then HFD + FF rats were treated with FF (30 mg/kg, once daily) via gavage for another 2 months. The pathological and tensional changes, protein expression of eNOS, and ER stress related genes in thoracic aorta were measured. Then impacts of palmitic acid (PA) and FF on EDV of thoracic aorta from normal female SD rats were observed. Ultimately the expression of ER stress related genes were assessed in primary mouse aortic endothelial cells (MAEC) treated by fenofibric acid (FA) and PA. We found that FF treatment improved serum lipid levels and pathological changes in thoracic aorta, accompanied with decreased ER stress and increased phosphorylation of eNOS. FF pretreatment also improved EDV impaired by different concentrations of PA treatment. The dose- and time-dependent inhibition of cell proliferation by PA were inverted by FA pretreatment. Phosphorylation of eNOS and expression of ER stress related genes were all inverted by FA pretreatment in PA-treated MAEC. Our findings show that fenofibrate recovers damaged EDV by chronic HFD feeding and acute stimulation of PA, this effect is related with decreased ER stress and increased phosphorylation of eNOS. - Highlights: • Fenofibrate treatment improved pathological changes in thoracic aorta by chronic high-fat-diet feeding. • Fenofibrate pretreatment improved endothelium-dependent vasodilation impaired by different concentrations of palmitic acid. • The inhibition of proliferation in endothelial cells by palmitic acid were inverted by fenofibric

  15. Nonesterified Fatty Acid-Induced Endoplasmic Reticulum Stress in Cattle Cumulus Oocyte Complexes Alters Cell Metabolism and Developmental Competence.

    Science.gov (United States)

    Sutton-McDowall, Melanie L; Wu, Linda L Y; Purdey, Malcolm; Abell, Andrew D; Goldys, Ewa M; MacMillan, Keith L; Thompson, Jeremy G; Robker, Rebecca L

    2016-01-01

    Reduced oocyte quality has been associated with poor fertility of high-performance dairy cows during peak lactation, due to negative energy balance. We examined the role of nonesterified fatty acids (NEFAs), known to accumulate within follicular fluid during under- and overnutrition scenarios, in causing endoplasmic reticulum (ER) stress of in vitro maturated cattle cumulus-oocyte complexes (COCs). NEFA concentrations were: palmitic acid (150 μM), oleic acid (200 μM), and steric acid (75 μM). Abattoir-derived COCs were randomly matured for 24 h in the presence of NEFAs and/or an ER stress inhibitor, salubrinal. Total and hatched blastocyst yields were negatively impacted by NEFA treatment compared with controls, but this was reversed by salubrinal. ER stress markers, activating transcription factor 4 (Atf4) and heat shock protein 5 (Hspa5), but not Atf6, were significantly up-regulated by NEFA treatment within whole COCs but reversed by coincubation with salubrinal. Likewise, glucose uptake and lactate production, measured in spent medium samples, showed a similar pattern, suggesting that cumulus cell metabolism is sensitive to NEFAs via an ER stress-mediated process. In contrast, while mitochondrial DNA copy number was recovered in NEFA-treated oocytes, oocyte autofluorescence of the respiratory chain cofactor, FAD, was lower following NEFA treatment of COCs, and this was not reversed by salubrinal, suggesting the negative impact was via reduced mitochondrial function. These results reveal the significance of NEFA-induced ER stress on bovine COC developmental competence, revealing a potential therapeutic target for improving oocyte quality during peak lactation. PMID:26658709

  16. Hardening with salicylic acid induces concentration-dependent changes in abscisic acid biosynthesis of tomato under salt stress.

    Science.gov (United States)

    Horváth, Edit; Csiszár, Jolán; Gallé, Ágnes; Poór, Péter; Szepesi, Ágnes; Tari, Irma

    2015-07-01

    The role of salicylic acid (SA) in the control of abscisic acid (ABA) biosynthesis is controversial although both plant growth regulators may accumulate in tissues under abiotic and biotic stress conditions. Hardening of tomato plants to salinity stress with 10(-4)M SA ("high SA") resulted in an up-regulation of ABA biosynthesis genes, zeaxanthin epoxidase (SlZEP1), 9-cis-epoxycarotenoid dioxygenase (SlNCED1) and aldehyde oxidases (SlAO1 and SlAO2) in the roots and led to ABA accumulation both in root and leaf tissues. In plants pre-treated with lower concentration of SA (10(-7)M, "low SA"), the up-regulation of SlNCED1 in the roots promoted ABA accumulation in the root tissues but the hormone concentration remained at control level in the leaves. Salt stress induced by 100mM NaCl reduced the transcript abundance of ABA biosynthetic genes and inhibited SlAO activity in plants hardened with "high SA", but the tissues maintained root ABA level over the untreated control. The combined effect of "high SA" and ABA under salt stress led to partially recovered photosynthetic activity, reduced ethylene production in root apices, and restored root growth, which is one of the main features of salt tolerance. Unlike "high SA", hardening with "low SA" had no influence on ethylene production, and led to reduced elongation of roots in plants exposed to 100mM NaCl. The up-regulation of carotenoid cleavage dioxygenases SlCCD1A and SlCCD1B by SA, which produce apocarotenoids, may open new pathways in SA sensing and signalling processes.

  17. Salicylic acid and gentisic acid induce RNA silencing-related genes and plant resistance to RNA pathogens.

    Science.gov (United States)

    Campos, Laura; Granell, Pablo; Tárraga, Susana; López-Gresa, Pilar; Conejero, Vicente; Bellés, José María; Rodrigo, Ismael; Lisón, Purificación

    2014-04-01

    We have observed that treatments with salicylic acid (SA) or gentisic acid (GA) induced resistance to RNA pathogens such as ToMV and CEVd in tomato and Gynura auriantiaca, respectively. Accumulation of SA and GA has been found to occur in plants infected by these pathogens, thus pointing out a possible defence role of both molecules. To study the molecular basis of the observed induced resistance to RNA pathogens the induction of silencing-related genes by SA and GA was considered. For that purpose, we searched for tomato genes which were orthologous to those described in Arabidopsis thaliana, such as AtDCL1, AtDCL2, AtDCL4, AtRDR1, AtRDR2 and AtRDR6, and we tracked their induction in tomato along virus and viroid infections. We observed that CEVd significantly induced all these genes in tomato, with the exception of ToRDR6, being the induction of ToDCL4 the most outstanding. Regarding the ToMV asymptomatic infection, with the exception of ToRDR2, we observed a significant induction of all the indicated silencing-related genes, being ToDCL2 the most induced gene. Subsequently, we analyzed their transcriptional activation by SA and at the time when ToMV was inoculated on plants. ToDCL2, ToRDR1 and ToRDR2 were significantly induced by both SA and GA, whereas ToDCL1 was only induced by SA. Such an induction resulted more effective by SA treatment, which is in agreement with the stronger SA-induced resistance observed. Our results suggest that the observed delay in the RNA pathogen accumulation could be due to the pre-induction of RNA silencing-related genes by SA or GA.

  18. Abscisic acid-induced rearrangement of intracellular structures associated with freezing and desiccation stress tolerance in the liverwort Marchantia polymorpha.

    Science.gov (United States)

    Akter, Khaleda; Kato, Masahiro; Sato, Yuki; Kaneko, Yasuko; Takezawa, Daisuke

    2014-09-15

    The plant growth regulator abscisic acid (ABA) is known to be involved in triggering responses to various environmental stresses such as freezing and desiccation in angiosperms, but little is known about its role in basal land plants, especially in liverworts, representing the earliest land plant lineage. We show here that survival rate after freezing and desiccation of Marchantia polymorpha gemmalings was increased by pretreatment with ABA in the presence of increasing concentrations of sucrose. ABA treatment increased accumulation of soluble sugars in gemmalings, and sugar accumulation was further increased by addition of sucrose to the culture medium. ABA treatment of gemmalings also induced accumulation of transcripts for proteins with similarity to late embryogenesis abundant (LEA) proteins, which accumulate in association with acquisition of desiccation tolerance in maturing seeds. Observation by light and electron microscopy indicated that the ABA treatment caused fragmentation of vacuoles with increased cytosolic volume, which was more prominent in the presence of a high concentration of external sucrose. ABA treatment also increased the density of chloroplast distribution and remarkably enlarged their volume. These results demonstrate that ABA induces drastic physiological changes in liverwort cells for stress tolerance, accompanied by accumulation of protectants against dehydration and rearrangement and morphological alterations of cellular organelles. PMID:25046754

  19. Protection against butyl p-hydroxybenzoic acid induced oxidative stress by Ocimum sanctum extract in mice liver.

    Science.gov (United States)

    Shah, Komal; Verma, Ramtej J

    2012-01-01

    Prime focus of the present investigation was to evaluate hepatoprotective potency of Ocimum sanctum (O. sanctum) aqueous extract against butyl p-hydroxybenzoic acid (butylparaben) toxicity in mice. Oral treatment of butylparaben (1320 mg/kg b.w./day) to mice for 30 days resulted in significant (p sanctum extracts in three different doses (100, 200 and 300 mg/kg b.w./day) resulted in significant (p sanctum with butylparaben resulted in dose-dependent and significant (p sanctum reduced butylparaben-induced changes in non-enzymatic and enzymatic antioxidants. The effect was significant (p sanctum ameliorated butylparaben-induced changes, showing maximum protection at 300 mg/kg b.w./day dose. Results of present study indicate that butylparaben-induced hepatotoxicity involves its ability to induce oxidative stress, whereas antihepatotoxic effect of O. sanctum was mainly due to its antioxidative potency. PMID:23061282

  20. Soyasaponins Protect Against Palmitic Acid-Induced Oxidative Stress in Primary Mouse Hepatocytes:Structure-Activity Relationship

    Institute of Scientific and Technical Information of China (English)

    Guang-zhi HE; Jia-ding CHEN; Yan-hong HU; Jin-bin CHEN; Jian-lin LV; Long-ying ZHA

    2014-01-01

    Objective To investigate the relationship between the structure and activity in protection of soyasaponins against palmitic acid (PA)-induced oxidative stress in primary mouse hepatocytes.Methods The primary mouse hepatocytes were treated with 0.05 mmol/L PA in the presence or absence of soyasaponins (10μg/ml) for 16h. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), the contents of malondialdehyde (MDA), triglyceride (TG) and reactive oxygen species (ROS) were determined.Results PA treatment significantly lowered cellular SOD and GSH-Px activities (P<0.05), increased the contents of MDA and TG (P<0.05) and the production of ROS in mitochondria was elevated (P<0.05). When compared to the treatment of PA alone, the combined treatment of soyasaponins and PA significantly increased the activities of SOD and GSH-Px (P<0.05) and decreased the contents of MDA, TG and ROS (P<0.05). It was found that soyasaponin-A1 or A2 significantly increased the cellular activities of SOD and GSH-Px (P<0.05) and decreased the contents of MDA and ROS as compared with soyasapogenol-A (P<0.05). Similarly, soyasaponin-I significantly increased activities of cellular SOD and GSH-Px (P<0.05) and decreased the content of ROS as compared with soyasapogenol-B (P<0.05).Conclusion Soyasaponins possess antioxidant activity against PA-induced oxidative stress in primary mouse hepatocytes. Soyasaponin-A1, A2 and I are stronger than their corresponding soyasapogenols (soyasapogenol-A and B) in antioxidant activity, probably due to the sugar moieties presented in their chemical structures.

  1. Maternal ethanol consumption during pregnancy enhances bile acid-induced oxidative stress and apoptosis in fetal rat liver.

    Science.gov (United States)

    Perez, Maria J; Velasco, Elena; Monte, Maria J; Gonzalez-Buitrago, Jose M; Marin, Jose J G

    2006-08-15

    Ethanol is able to cross the placenta, which may cause teratogenicity. Here we investigated whether ethanol consumption during pregnancy (ECDP), even at doses unable to cause malformation, might increase the susceptibility of fetal rat liver to oxidative insults. Since cholestasis is a common condition in alcoholic liver disease and pregnancy, exposure to glycochenodeoxycholic acid (GCDCA) has been used here as the oxidative insult. The mothers received drinking water without or with ethanol from 4 weeks before mating until term, when placenta, maternal liver, and fetal liver were used. Ethanol induced a decreased GSH/GSSG ratio in these organs, together with enhanced gamma-glutamylcysteine synthetase and glutathione reductase activities in both placenta and fetal liver. Lipid peroxidation in placenta and fetal liver was enhanced by ethanol, although it had no effect on caspase-3 activity. Although the basal production of reactive oxygen species (ROS) was higher by fetal (FHs) than by maternal (AHs) hepatocytes in short-term cultures, the production of ROS in response to the presence of varying GCDCA concentrations was higher in AHs and was further increased by ECDP, which was associated to a more marked impairment in mitochondrial function. Moreover, GCDCA-induced apoptosis was increased by ECDP, as revealed by enhanced Bax-alpha/Bcl-2 ratio (both in AHs and FHs) and the activity of caspase-8 (only in AHs) and caspase-3. In sum, our results indicate that although AHs are more prone than FHs to producing ROS, at doses unable to cause maternal liver damage ethanol consumption causes oxidative stress and apoptosis in fetal liver.

  2. Exercise, Stress Resistance, and Central Serotonergic Systems

    OpenAIRE

    Greenwood, Benjamin N.; Fleshner, Monika

    2011-01-01

    Voluntary exercise reduces the incidence of stress-related psychiatric disorders in humans and prevents serotonin-dependent behavioral consequences of stress in rodents. Evidence reviewed herein is consistent with the hypothesis that exercise increases stress resistance by producing neuroplasticity at multiple sites of the central serotonergic system, which all help to limit the behavioral impact of acute increases in serotonin during stressor exposure.

  3. LINK BETWEEN OXIDATIVE STRESS AND INSULIN RESISTANCE

    Institute of Scientific and Technical Information of China (English)

    Lan-fang Li; Jian Li

    2007-01-01

    Many studies on oxidative stress, insulin resistance, and antioxidant treatment have shown that increased oxidative stress may accelerate the development of diabetic complications through the excessive glucose and free fatty acids metabolism in diabetic and insulin-resistant states. Many pathogenic mechanisms such as insulin receptor substrate phosphorylation are involved in insulin resistance induced by oxidative stress. And antioxidant treatments can show benefits in animal models of diabetes mellitus and insulin resistance. However, negative evidence from large clinical trials suggests that new and more powerful antioxidants need to be studied to demonstrate whether antioxidants can be effective in treating diabetic complications. Furthermore, it appears that oxidative stress is only one of the factors contributing to diabetic complications. Thus, antioxidant treatment would most likely be more effective if it were coupled with other treatments for diabetic complications.

  4. ESTIMATION OF INCREASE OF STRESS RESISTANCE AMONG STUDENTS

    OpenAIRE

    Drobysheva O. M.

    2015-01-01

    By results of the estimation of stress resistance on dynamics of the regulation-adaptive status we can observe, that the autogenic training at the end of one academic year did not cause authentic changes in stress resistance in students with high and low levels of stress resistance. At the same time, it raised stress resistance for persons with a moderate level of stress resistance

  5. What is the evidence for stress resistance and slowed aging?

    Science.gov (United States)

    Hamilton, Karyn L; Miller, Benjamin F

    2016-09-01

    Stress resistance is thought to contribute to slowed-aging, although cause and effect between the two is controversial. On October 30, 2015 researchers gathered at the Front Range Consortium on Stress Resistance and Slowed Aging in Fort Collins, CO, to discuss what the current evidence is that stress resistance imparts slowed aging. Included in that discussion was defining stress resistance, distinguishing if there are key stresses to which resistance imparts slowed aging, what models aid in our understanding of stress resistance and aging, and how to translate that knowledge into slowed aging treatment. The following article is a brief summary of that discussion and recommendations for moving forward. PMID:27268049

  6. Gibberellic Acid-Induced Aleurone Layers Responding to Heat Shock or Tunicamycin Provide Insight into the N-Glycoproteome, Protein Secretion, and Endoplasmic Reticulum Stress

    DEFF Research Database (Denmark)

    Barba Espin, Gregorio; Dedvisitsakul, Plaipol; Hägglund, Per;

    2014-01-01

    The growing relevance of plants for the production of recombinant proteins makes understanding the secretory machinery, including the identification of glycosylation sites in secreted proteins, an important goal of plant proteomics. Barley (Hordeum vulgare) aleurone layers maintained in vitro...... respond to gibberellic acid by secreting an array of proteins and provide a unique system for the analysis of plant protein secretion. Perturbation of protein secretion in gibberellic acid-induced aleurone layers by two independent mechanisms, heat shock and tunicamycin treatment, demonstrated overlapping...... shock proteins, decreased in heat-shocked aleurone layers. Additionally, glycopeptide enrichment and N-glycosylation analysis identified 73 glycosylation sites in 65 aleurone layer proteins, with 53 of the glycoproteins found in extracellular fractions and 36 found in intracellular fractions...

  7. Gibberellic acid-induced aleurone layers responding to heat shock or tunicamycin provide insight into the N-glycoproteome, protein secretion, and endoplasmic reticulum stress.

    Science.gov (United States)

    Barba-Espín, Gregorio; Dedvisitsakul, Plaipol; Hägglund, Per; Svensson, Birte; Finnie, Christine

    2014-02-01

    The growing relevance of plants for the production of recombinant proteins makes understanding the secretory machinery, including the identification of glycosylation sites in secreted proteins, an important goal of plant proteomics. Barley (Hordeum vulgare) aleurone layers maintained in vitro respond to gibberellic acid by secreting an array of proteins and provide a unique system for the analysis of plant protein secretion. Perturbation of protein secretion in gibberellic acid-induced aleurone layers by two independent mechanisms, heat shock and tunicamycin treatment, demonstrated overlapping effects on both the intracellular and secreted proteomes. Proteins in a total of 22 and 178 two-dimensional gel spots changing in intensity in extracellular and intracellular fractions, respectively, were identified by mass spectrometry. Among these are proteins with key roles in protein processing and secretion, such as calreticulin, protein disulfide isomerase, proteasome subunits, and isopentenyl diphosphate isomerase. Sixteen heat shock proteins in 29 spots showed diverse responses to the treatments, with only a minority increasing in response to heat shock. The majority, all of which were small heat shock proteins, decreased in heat-shocked aleurone layers. Additionally, glycopeptide enrichment and N-glycosylation analysis identified 73 glycosylation sites in 65 aleurone layer proteins, with 53 of the glycoproteins found in extracellular fractions and 36 found in intracellular fractions. This represents major progress in characterization of the barley N-glycoproteome, since only four of these sites were previously described. Overall, these findings considerably advance knowledge of the plant protein secretion system in general and emphasize the versatility of the aleurone layer as a model system for studying plant protein secretion.

  8. MyD88 signaling in the CNS is required for development of fatty acid induced leptin resistance and diet-induced obesity

    OpenAIRE

    Kleinridders, Andre; Schenten, Dominik; Mauer, Jan; Wunderlich, F. Thomas; Okamura, Tomoo; Koenner, A. Christine; Belgardt, Bengt F.; Bruening, Jens C.; Medzhitov, Ruslan

    2009-01-01

    Obesity-associated activation of inflammatory pathways represents a key step in the development of insulin resistance in peripheral organs, partially via activation of TLR-4 signaling by fatty acids. Here we demonstrate that palmitate acting in the central nervous system (CNS) inhibits leptin-induced anorexia and Stat-3 activation. To determine the functional significance of TLR signaling in the CNS in the development of leptin resistance and diet-induced obesity in vivo, we have characterize...

  9. 40 CFR 91.427 - Catalyst thermal stress resistance evaluation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress resistance... Procedures § 91.427 Catalyst thermal stress resistance evaluation. (a)(1) The purpose of the evaluation procedure specified in this section is to determine the effect of thermal stress on catalyst...

  10. 40 CFR 90.427 - Catalyst thermal stress resistance evaluation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress resistance... Gaseous Exhaust Test Procedures § 90.427 Catalyst thermal stress resistance evaluation. (a) The purpose of... catalyst conversion efficiency for Phase 1 engines. The thermal stress is imposed on the test catalyst...

  11. Resistance to ursolic acid-induced apoptosis through involvement of melanogenesis and COX-2/PGE2 pathways in human M4Beu melanoma cancer cells.

    Science.gov (United States)

    Hassan, Lama; Pinon, Aline; Limami, Youness; Seeman, Josiane; Fidanzi-Dugas, Chloe; Martin, Frederique; Badran, Bassam; Simon, Alain; Liagre, Bertrand

    2016-07-01

    Melanoma is one of the most aggressive forms of cancer with a continuously growing incidence worldwide and is usually resistant to chemotherapy agents, which is due in part to a strong resistance to apoptosis. Previously, we had showed that B16-F0 murine melanoma cells undergoing apoptosis are able to delay their own death induced by ursolic acid (UA), a natural pentacyclic triterpenoid compound. We had demonstrated that tyrosinase and TRP-1 up-regulation in apoptotic cells and the subsequent production of melanin were implicated in an apoptosis resistance mechanism. Several resistance mechanisms to apoptosis have been characterized in melanoma such as hyperactivation of DNA repair mechanisms, drug efflux systems, and reinforcement of survival signals (PI3K/Akt, NF-κB and Raf/MAPK pathways). Otherwise, other mechanisms of apoptosis resistance involving different proteins, such as cyclooxygenase-2 (COX-2), have been described in many cancer types. By using a strategy of specific inhibition of each ways, we suggested that there was an interaction between melanogenesis and COX-2/PGE2 pathway. This was characterized by analyzing the COX-2 expression and activity, the expression of tyrosinase and melanin production. Furthermore, we showed that anti-proliferative and proapoptotic effects of UA were mediated through modulation of multiple signaling pathways including Akt and ERK-1/2 proteins. Our study not only uncovers underlying molecular mechanisms of UA action in human melanoma cancer cells but also suggest its great potential as an adjuvant in treatment and cancer prevention. PMID:27262506

  12. Glucose amplifies fatty acid-induced endoplasmic reticulum stress in pancreatic beta-cells via activation of mTORC1.

    Directory of Open Access Journals (Sweden)

    Etti Bachar

    Full Text Available BACKGROUND: Palmitate is a potent inducer of endoplasmic reticulum (ER stress in beta-cells. In type 2 diabetes, glucose amplifies fatty-acid toxicity for pancreatic beta-cells, leading to beta-cell dysfunction and death. Why glucose exacerbates beta-cell lipotoxicity is largely unknown. Glucose stimulates mTORC1, an important nutrient sensor involved in the regulation of cellular stress. Our study tested the hypothesis that glucose augments lipotoxicity by stimulating mTORC1 leading to increased beta-cell ER stress. PRINCIPAL FINDINGS: We found that glucose amplifies palmitate-induced ER stress by increasing IRE1alpha protein levels and activating the JNK pathway, leading to increased beta-cell apoptosis. Moreover, glucose increased mTORC1 activity and its inhibition by rapamycin decreased beta-cell apoptosis under conditions of glucolipotoxicity. Inhibition of mTORC1 by rapamycin did not affect proinsulin and total protein synthesis in beta-cells incubated at high glucose with palmitate. However, it decreased IRE1alpha expression and signaling and inhibited JNK pathway activation. In TSC2-deficient mouse embryonic fibroblasts, in which mTORC1 is constitutively active, mTORC1 regulated the stimulation of JNK by ER stressors, but not in response to anisomycin, which activates JNK independent of ER stress. Finally, we found that JNK inhibition decreased beta-cell apoptosis under conditions of glucolipotoxicity. CONCLUSIONS/SIGNIFICANCE: Collectively, our findings suggest that mTORC1 mediates glucose amplification of lipotoxicity, acting through activation of ER stress and JNK. Thus, mTORC1 is an important transducer of ER stress in beta-cell glucolipotoxicity. Moreover, in stressed beta-cells mTORC1 inhibition decreases IRE1alpha protein expression and JNK activity without affecting ER protein load, suggesting that mTORC1 regulates the beta-cell stress response to glucose and fatty acids by modulating the synthesis and activity of specific

  13. Maternal mediation, stress inoculation, and the development of neuroendocrine stress resistance in primates

    OpenAIRE

    Parker, Karen J.; Buckmaster, Christine L.; Sundlass, Karan; Schatzberg, Alan F.; Lyons, David M.

    2006-01-01

    The stress inoculation hypothesis presupposes that brief intermittent stress exposure early in life induces the development of subsequent stress resistance in human and nonhuman primates. Rodent studies, however, suggest a role for maternal care rather than stress exposure per se (i.e., the maternal mediation hypothesis). To investigate these two hypotheses, we examined maternal care and the development of stress resistance after exposure to brief intermittent infant stress (IS), mother–infan...

  14. Palmitic Acid-Induced Neuron Cell Cycle G2/M Arrest and Endoplasmic Reticular Stress through Protein Palmitoylation in SH-SY5Y Human Neuroblastoma Cells

    Directory of Open Access Journals (Sweden)

    Yung-Hsuan Hsiao

    2014-11-01

    Full Text Available Obesity-related neurodegenerative diseases are associated with elevated saturated fatty acids (SFAs in the brain. An increase in SFAs, especially palmitic acid (PA, triggers neuron cell apoptosis, causing cognitive function to deteriorate. In the present study, we focused on the specific mechanism by which PA triggers SH-SY5Y neuron cell apoptosis. We found that PA induces significant neuron cell cycle arrest in the G2/M phase in SH-SY5Y cells. Our data further showed that G2/M arrest is involved in elevation of endoplasmic reticular (ER stress according to an increase in p-eukaryotic translation inhibition factor 2α, an ER stress marker. Chronic exposure to PA also accelerates beta-amyloid accumulation, a pathological characteristic of Alzheimer’s disease. Interestingly, SFA-induced ER stress, G2/M arrest and cell apoptosis were reversed by treatment with 2-bromopalmitate, a protein palmitoylation inhibitor. These findings suggest that protein palmitoylation plays a crucial role in SFA-induced neuron cell cycle G2/M arrest, ER stress and apoptosis; this provides a novel strategy for preventing SFA-induced neuron cell dysfunction.

  15. Abscisic Acid-Induced H2O2 Accumulation Enhances Antioxidant Capacity in Pumpkin-Grafted Cucumber Leaves under Ca(NO3)2 Stress

    Science.gov (United States)

    Shu, Sheng; Gao, Pan; Li, Lin; Yuan, Yinghui; Sun, Jin; Guo, Shirong

    2016-01-01

    With the aim to clarifying the role of the ABA/H2O2 signaling cascade in the regulating the antioxidant capacity of grafted cucumber plants in response to Ca(NO3)2 stress, we investigated the relationship between ABA-mediated H2O2 production and the activities of antioxidant enzymes in the leaves of pumpkin-grafted cucumber seedlings. The results showed that both ABA and H2O2 were detected in pumpkin-grafted cucumber seedlings in response to Ca(NO3)2 treatment within 0.5 h in the leaves and peaked at 3 and 6 h after Ca(NO3)2 treatment, respectively, compared to the levels under control conditions. The activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase (POD) in pumpkin-grafted cucumber leaves gradually increased over time and peaked at 12 h of Ca(NO3)2 stress. Furthermore, in the leaves of pumpkin-grafted cucumber seedlings, the H2O2 generation, the antioxidant enzyme activities and the expression of SOD, POD and cAPX were strongly blocked by an inhibitor of ABA under Ca(NO3)2 stress, but this effect was eliminated by the addition of exogenous ABA. Moreover, the activities and gene expressions of these antioxidant enzymes in pumpkin-grafted leaves were almost inhibited under Ca(NO3)2 stress by pretreatment with ROS scavengers. These results suggest that the pumpkin grafting-induced ABA accumulation mediated H2O2 generation, resulting in the induction of antioxidant defense systems in leaves exposed to Ca(NO3)2 stress in the ABA/H2O2 signaling pathway. PMID:27746808

  16. Mitochondrial genome depletion in human liver cells abolishes bile acid-induced apoptosis: role of the Akt/mTOR survival pathway and Bcl-2 family proteins.

    Science.gov (United States)

    Marin, Jose J G; Hernandez, Alicia; Revuelta, Isabel E; Gonzalez-Sanchez, Ester; Gonzalez-Buitrago, Jose M; Perez, Maria J

    2013-08-01

    Acute accumulation of bile acids in hepatocytes may cause cell death. However, during long-term exposure due to prolonged cholestasis, hepatocytes may develop a certain degree of chemoresistance to these compounds. Because mitochondrial adaptation to persistent oxidative stress may be involved in this process, here we have investigated the effects of complete mitochondrial genome depletion on the response to bile acid-induced hepatocellular injury. A subline (Rho) of human hepatoma SK-Hep-1 cells totally depleted of mitochondrial DNA (mtDNA) was obtained, and bile acid-induced concentration-dependent activation of apoptosis/necrosis and survival signaling pathways was studied. In the absence of changes in intracellular ATP content, Rho cells were highly resistant to bile acid-induced apoptosis and partially resistant to bile acid-induced necrosis. In Rho cells, both basal and bile acid-induced generation of reactive oxygen species (ROS), such as hydrogen peroxide and superoxide anion, was decreased. Bile acid-induced proapoptotic signals were also decreased, as evidenced by a reduction in the expression ratios Bax-α/Bcl-2, Bcl-xS/Bcl-2, and Bcl-xS/Bcl-xL. This was mainly due to a downregulation of Bax-α and Bcl-xS. Moreover, in these cells the Akt/mTOR pathway was constitutively activated in a ROS-independent manner and remained similarly activated in the presence of bile acid treatment. In contrast, ERK1/2 activation was constitutively reduced and was not activated by incubation with bile acids. In conclusion, these results suggest that impaired mitochondrial function associated with mtDNA alterations, which may occur in liver cells during prolonged cholestasis, may activate mechanisms of cell survival accounting for an enhanced resistance of hepatocytes to bile acid-induced apoptosis. PMID:23597504

  17. Effects of exercise training and diet on lipid kinetics during free fatty acid-induced insulin resistance in older obese humans with impaired glucose tolerance

    DEFF Research Database (Denmark)

    Solomon, Thomas; Haus, Jacob M; Marchetti, Christine M;

    2009-01-01

    Elevated free fatty acids (FFA) are implicated with insulin resistance at the cellular level. However, the contribution of whole body lipid kinetics to FFA-induced insulin resistance is not well understood, and the effect of exercise and diet on this metabolic defect is not known. We investigated.......8 +/- 1.8 kg/m(2)) or a eucaloric (n = 8; 67 +/- 2 yr, 35.3 +/- 2.1 kg/m(2)) diet and aerobic exercise (1 h/day at 65% of maximal oxygen uptake) regimen. Lipid kinetics ([1-(14)C]palmitate) were assessed throughout a 7-h, 40 mU x m(-2) x min(-1) hyperinsulinemic euglycemic clamp, during which insulin...... concentrations (2,123 +/- 261 vs. 1,764 +/- 194 micromol/l, P body FFA(ox) was improved in both groups at rest and during...

  18. Effects of exogenous plant growth regulator abscisic acid-induced resistance in rice on the expression of vitellogenin mRNA in Nilaparvata lugens (Hemiptera: Delphacidae) adult females.

    Science.gov (United States)

    Liu, Jing-Lan; Chen, Xiao; Zhang, Hong-Mei; Yang, Xia; Wong, Andrew

    2014-01-01

    Recent study showed that exogenous abscisic acid (ABA) acts as a regulator of plant resistance. This study investigated average injury scale and callose contents of rice, and vitellogenin (Nlvg) mRNA expression in Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) adult females after third instar nymphs fed on exogenous ABA-treated susceptible [Taichung Native one (TN1)] and moderately resistant (IR42) rice cultivars. The results showed that exogenous ABA significantly decreased average injury scale of rice and Nlvg mRNA expression in N. lugens adults compared with the control (without ABA spraying). Nlvg mRNA expression in N. lugens adults decreased significantly after third instar nymphs fed on ABA-treated (5, 20, and 40 mg/liter) TN1 for 1 and 2 d, and for IR42, after fed on ABA-treated (20 and 40 mg/liter) rice plants for 1 d and after fed on ABA-treated (5, 20, and 40 mg/liter) rice for 2 d decreased significantly. The callose contents showed no significant change for TN1, while for IR42, significantly increased in roots and sheathes after N. lugens infestation under ABA treatments (20 and 40 mg/liter) compared with the control. The decrease of Nlvg mRNA expression may be partially attributed to the increase of callose content of plants. The results provide a profile for concerning the effects of ABA-induced rice plants' defenses on phloem-feeding insects.

  19. Fluvoxamine Attenuated Endoplasmic Reticulum Stress-Induced Leptin Resistance

    OpenAIRE

    Hosoi, Toru; Miyahara, Tsuyoshi; Kayano, Takaaki; Yokoyama, Shota; Ozawa, Koichiro

    2012-01-01

    Increasing evidence indicates that endoplasmic reticulum stress (ER stress) is involved in the development of metabolic syndrome. However, pharmacological treatments targeting ER stress are not well understood. In the present study, we found that fluvoxamine, a selective serotonin reuptake inhibitor used for depression, can attenuate ER stress-induced “leptin resistance,” i.e., insensitivity to the anti-obesity hormone leptin. Treatment with tunicamycin, an ER stress-inducing reagent, caused ...

  20. Redefining ‘stress resistance gene’, and why it matters

    Science.gov (United States)

    Many plant biologists work on the identification of genes related to abiotic stress resistance, but the term ‘stress resistance gene’ is widely used without proper definition. Here it is argued that there is a need to update our understanding of this term and for standardization to facilitate integr...

  1. Kainic acid-induced endoplasmic reticulum stress model%红藻氨酸诱导内质网应激模型的途径

    Institute of Scientific and Technical Information of China (English)

    袁磊; 张海霞; 钱诗蕾; 徐斌; 龚济钦; 刘湘华; 唐园; 禹华旭

    2014-01-01

    背景:前期研究表明,海马内注射红藻氨酸海可诱发兴奋性红藻氨酸受体KA1亚受体在海马神经元的表达明显上调,内质网应激标志物磷酸化真核翻译起始因子2α表达增加并伴随细胞死亡。目的:探讨红藻氨酸海马内注射后内质网应激发生的机制。方法:取昆明小鼠32只,将0.15 nmol 红藻氨酸注入海马CA1区域,注射时间为60 s。分别于红藻氨酸注射后第1,2,3,4,5,6,8,12小时灌注取脑,灌注取脑前进行Bederson体征评分,然后行全脑切片FJB染色分析与免疫荧光双标记观察。结果与结论:①红藻氨酸注射后第3,4,5,6,8小时,Bederson 体征评分表明中枢神经功能出现明显损伤,FJB染色示小鼠海马内神经元死亡明显;注射后第1,2,12小时,Bederson体征评分中枢神经功能未见明显损伤,FJB染色小鼠海马神经元死亡结果不明显。②根据FJB结果,取第3,8小时的脑片做免疫组化。海马内注射红藻氨酸后导致海马神经元中KA1和磷酸化真核翻译起始因子2α在相同的时间点表达明显上调,将KA1与磷酸化真核翻译起始因子2α图片结果进行叠加处理,两者完全重合,表明KA1的表达和内质网应激发生在同一个神经细胞内。结果表明红藻氨酸首先诱导了兴奋性膜上受体KA1表达的上调,其KA1的表达上调可能引起细胞内质网功能紊乱,导致内质网应激反应,并进一步促进了神经细胞的死亡。%BACKGROUND:Previous studies have shown that kainic acid injected into hippocampus can significantly upregulate the expression of excitatory KA1 subunit of the kainate receptor in the hippocampus, and endoplasmic reticulum stress markers, phosphorylation of the alpha subunit of eukaryotic initiation factor 2, accompanied by celldeath. OBJECTIVE:To explore the mechanism of endoplasmic reticulum stress after kainic acid is injected into the

  2. Acetylsalicylic acid-induced oxidative stress, cell cycle arrest, apoptosis and mitochondrial dysfunction in human hepatoma HepG2 cells.

    Science.gov (United States)

    Raza, Haider; John, Annie; Benedict, Sheela

    2011-10-01

    It is widely accepted that non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin, reduce the risk of cancer. The anti-cancer and anti-inflammatory effects of NSAIDs are associated with the inhibition of prostaglandin synthesis and cyclooxygenase-2 activity. Several other mechanisms which contribute to the anti-cancer effect of these drugs in different cancer models both in vivo and in vitro are also presumed to be involved. The precise molecular mechanism, however, is still not clear. We investigated, therefore, the effects of acetylsalicylic acid (ASA, aspirin) on multiple cellular and functional targets, including mitochondrial bioenergetics, using human hepatoma HepG2 cancer cells in culture. Our results demonstrate that ASA induced G0/G1 cell cycle arrest and apoptosis in HepG2 cells. ASA increased the production of reactive oxygen species, reduced the cellular glutathione (GSH) pool and inhibited the activities of the mitochondrial respiratory enzyme complexes, NADH-ubiquinone oxidoreductase (complex I), cytochrome c oxidase (complex IV) and the mitochondrial matrix enzyme, aconitase. Apoptosis was triggered by alteration in mitochondrial permeability transition, inhibition of ATP synthesis, decreased expression of the anti-apoptotic protein Bcl-2, release of cytochrome c and activation of pro-apoptotic caspase-3 and the DNA repairing enzyme, poly (-ADP-ribose) polymerase (PARP). These findings strongly suggest that ASA-induced toxicity in human hepatoma HepG2 cells is mediated by increased metabolic and oxidative stress, accompanied by mitochondrial dysfunction which result in apoptosis.

  3. Study on the Resistance of Cucumber to Temperature Stresses

    Institute of Scientific and Technical Information of China (English)

    Ma Dehua; Pang Jin'an; Huo Zhenrong; Li Shuju; Du Shengli

    2000-01-01

    Four cucumber (Cucumis sativus L. ) inbred lines with different resistances to temperature stress were used in this experiment. The seedlings of line Q10 and Q21 that have high resistance to chilling stress also have high resistance to heat stress. The seedlings of line T94 and T55 that have lower resistance to chilling stress also have lower resistance to heat stress. It seems that the resistance of cucumber seedlings to different temperature stresses was similar. The influences of chilling and heat stress on the germination ability of cucumber seeds were different. Under the chilling stress, the germination percentage decreased less, and the germination velocity decreased more,so the germination index decreased significantly. Under the heat stress, the germination percentage and velocity of the seeds with high resistance decreased less and those of the seeds with lower resistance decreased more. The differences among the lines became more evident under the extreme heat condition. The content of chlorophyll decreased under the different temperature stresses, the content of chlorophyll a decreased more than that of chlorophyll b, so the value of chlorophyll a/b decreased.The temperature stress inhibited the photosynthesis of cucumber seedlings significantly. After chilling or heat treatment, the net photosynthetic rate (Pn) decreased remarkably. With the stomatal conductance (Gs) decreased, the stomatal limited value (Is) decreased, the intercellular CO2 concentration (Ci) increased, and both the apparent quantum efficiencies (AQE) and the carboxylation efficiencies (CE) decreased. Results showed that the non-stomatal factors were the main causes of Pn decrease, and the photosynthetic mechanism was destroyed remarkably.

  4. Overexpression of VOZ2 confers biotic stress tolerance but decreases abiotic stress resistance in Arabidopsis

    OpenAIRE

    Nakai, Yusuke; Fujiwara, Sumire; Kubo, Yasuyuki; Sato, Masa H.

    2013-01-01

    VOZ (vascular plant one zinc-finger protein) is a plant specific one-zinc finger type transcriptional activator, which is highly conserved through land plant evolution. We have previously shown that loss-of-function mutations in VOZ1 and VOZ2 showed increased cold and drought stress tolerances whereas decreased biotic stress resistance in Arabidopsis. Here, we demonstrate that transgenic plants overexpressing VOZ2 impairs freezing and drought stress tolerances but increases resistance to a fu...

  5. Screening for Stress Resistance Mutations in the Mouse

    Directory of Open Access Journals (Sweden)

    Wallace S Chick

    2014-09-01

    Full Text Available Longevity is correlated with stress resistance in many animal models. However, previous efforts through the boosting of the antioxidant defense system did not extend life span, suggesting that longevity related stress resistance is mediated by other uncharacterized pathways. We have developed a high-throughput platform for screening and rapid identification of novel genetic mutants in the mouse that are stress-resistant. Selection for resistance to stressors occurs in mutagenized mouse embryonic stem (ES cells, which are carefully treated so as to maintain pluripotency for mouse production. Initial characterization of these mutant ES cells revealed mutations in Pigl, Tiam1, and Rffl, among others. These genes are implicated in glycosylphosphatidylinositol biosynthesis, NADPH oxidase function, and inflammation. These mutants: (1 are resistant to two different oxidative stressors, paraquat and the omission of 2-mercaptoethanol, (2 have reduced levels of endogenous reactive oxygen species (ROS, (3 are capable of generating live mice, and (4 transmit the stress resistance phenotype to the mice. This strategy offers an efficient way to select for new mutants expressing a stress resistance phenotype, to rapidly identify the causative genes, and to develop mice for in vivo studies.

  6. Stress stimulus induced resistance to Cladosporium cucumerinum in cucumber seeding.

    Science.gov (United States)

    Zhao, Huan; Wang, Bo-Chu; Zhao, Hu-Cheng; Wang, Jing Bo

    2005-07-25

    Up to date, the studies of plant induced resistance have become the focus in plant pathology and physiology. During the course of pathogens penetrating the plant cell, besides of chemical secretion, the pathogens may generate mechanical signal caused by the physical pressure on the plant cell. In the non-host resistance, both the chemical signal and the mechanical stress signal are considered to have contribution to the entire defense reaction acted by the plant. The penetration of pathogen Cladosporium cucumerinum to cucumber is thought to be one of the model in research of plant induced resistance. In the current study, as a mechanical signal elicitor, the appropriate stress stimulus was proved to effectually induce the resistance of cucumber seedling to C. cucumerinum. After the treatment of the stress stimulus on leaves, the activities of resistance-related enzymes were significantly increased, such as phenylanine ammonia lyase (PAL), peroxidase (POD). Also, we found that stress stimulation may cause synthesis of lignin, which acts as the physical barrier to defense the pathogens. The results suggest that stress stimulation may not only enhance ability of the plant cell resistance to pathogen penetration but also elicit the accumulation of pathogens suppression or antimicrobial chemical substance in the plant cell. PMID:16002268

  7. Resistance Responses of Carbon Fiber Cement to Cycled Compressive Stresses

    Institute of Scientific and Technical Information of China (English)

    SHUI Zhonghe; LI Chao; LIAO Weidong

    2005-01-01

    The stress-resistance relationship of carbon fiber cement was studicd. Attention has been paid to explore the improvement of the stress-resistance sensitivity under cycled stress restriction. The prismy carbon fiber cement sensors were pre-fabricated. The factors such as contents of carbon fibers, silica fume, dispersant and the w/ c were taken into account. The electrical resistance variations with the dynamic and static loads were simulated using a strain-controlled test machine. The test results show that there is an optimal fiber content, with which the compression-sensitivity achieves a high level. The addition of silica fume can improve the sensitivity. Urder the optimal test conditions, the measured resistances can greatly correspond with the changes of the load.

  8. Fluvoxamine attenuated endoplasmic reticulum stress-induced leptin resistance

    Directory of Open Access Journals (Sweden)

    Toru eHosoi

    2012-01-01

    Full Text Available Increasing evidence indicates that endoplasmic reticulum stress (ER stress is involved in the development of metabolic syndrome. However, pharmacological treatments targeting ER stress are not well understood. In the present study, we found that fluvoxamine, a selective serotonin reuptake inhibitor used for depression, can attenuate ER stress-induced leptin resistance, i.e. insensitivity to the anti-obesity hormone leptin. Treatment with tunicamycin, an ER stress-inducing reagent, caused cell death which was significantly inhibited by fluvoxamine. Leptin activates JAK2-STAT3 signaling. ER stress caused an impairment of leptin-induced STAT3 phosphorylation which was reversed by fluvoxamine. Fluvoxamine would be a novel leptin-sensitizing drug, which targets ER stress.

  9. Cross-stress resistance in Saccharomyces cerevisiae yeast—new insight into an old phenomenon

    OpenAIRE

    Święciło, Agata

    2016-01-01

    Acquired stress resistance is the result of mild stress causing the acquisition of resistance to severe stress of the same or a different type. The mechanism of “same-stress” resistance (resistance to a second, strong stress after mild primary stress of the same type) probably depends on the activation of defense and repair mechanisms specific for a particular type of stress, while cross-stress resistance (i.e., resistance to a second, strong stress after a different type of mild primary stre...

  10. Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Haitao Shi; Tiantian Ye; Ning Han; Hongwu Bian; Xiaodong Liu; Zhulong Chan

    2015-01-01

    Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NaHS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interest-ingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcrip-tional y regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors.

  11. Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis.

    Science.gov (United States)

    Shi, Haitao; Ye, Tiantian; Han, Ning; Bian, Hongwu; Liu, Xiaodong; Chan, Zhulong

    2015-07-01

    Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NaHS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interestingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcriptionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors.

  12. Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis.

    Science.gov (United States)

    Shi, Haitao; Ye, Tiantian; Han, Ning; Bian, Hongwu; Liu, Xiaodong; Chan, Zhulong

    2015-07-01

    Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NaHS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NaHS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interestingly, MIR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcriptionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors. PMID:25329496

  13. Arabidopsis PED2 positively modulates plant drought stress resistance

    Institute of Scientific and Technical Information of China (English)

    Haitao Shi; Tiantian Ye; Fan Yang; Zhulong Chan

    2015-01-01

    Abscisic acid (ABA) is an important phytohormone that functions in seed germination, plant development, and multiple stress responses. Arabidopsis Peroxisome defective 2 (AtPED2) (also known as AtPEXOXIN14, AtPEX14), is involved in the intracellular transport of thiolase from the cytosol to glyoxysomes, and perosisomal matrix protein import in plants. In this study, we assigned a new role for AtPED2 in drought stress resistance. The transcript level of AtPED2 was down-regulated by ABA and abiotic stress treatments. AtPED2 knockout mutants were insensitive to ABA-mediated seed germination, primary root elongation, and stomatal response, while AtPED2 over-expressing plants were sensitive to ABA in comparison to wide type (WT). AtPED2 also positively regulated drought stress resistance, as evidenced by the changes of water loss rate, electrolyte leakage, and survival rate. Notably, AtPED2 positively modulated expression of several stress-responsive genes (RAB18, RD22, RD29A, and RD29B), positively affected underlying antioxidant enzyme activities and negatively regulated reactive oxygen species (ROS) level under drought stress conditions. Moreover, multiple carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines were also positively regulated by AtPED2. Taken together, these results indicated a positive role for AtPED2 in drought resistance, through modulation of stress-responsive genes expression, ROS metabolism, and metabolic homeostasis, at least partially.

  14. Alloy SCR-3 resistant to stress corrosion cracking

    International Nuclear Information System (INIS)

    Austenitic stainless steel is used widely because the corrosion resistance, workability and weldability are excellent, but the main fault is the occurrence of stress corrosion cracking in the environment containing chlorides. Inconel 600, most resistant to stress corrosion cracking, is not necessarily safe under some severe condition. In the heat-affected zone of SUS 304 tubes for BWRs, the cases of stress corrosion cracking have occurred. The conventional testing method of stress corrosion cracking using boiling magnesium chloride solution has been problematical because it is widely different from actual environment. The effects of alloying elements on stress corrosion cracking are remarkably different according to the environment. These effects were investigated systematically in high temperature, high pressure water, and as the result, Alloy SCR-3 with excellent stress corrosion cracking resistance was found. The physical constants and the mechanical properties of the SCR-3 are shown. The states of stress corrosion cracking in high temperature, high pressure water containing chlorides and pure water, polythionic acid, sodium phosphate solution and caustic soda of the SCR-3, SUS 304, Inconel 600 and Incoloy 800 are compared and reported. (Kako, I.)

  15. Arabidopsis PED2 positively modulates plant drought stress resistance.

    Science.gov (United States)

    Shi, Haitao; Ye, Tiantian; Yang, Fan; Chan, Zhulong

    2015-09-01

    Abscisic acid (ABA) is an important phytohormone that functions in seed germination, plant development, and multiple stress responses. Arabidopsis Peroxisome defective 2 (AtPED2) (also known as AtPEXOXIN14, AtPEX14), is involved in the intracellular transport of thiolase from the cytosol to glyoxysomes, and perosisomal matrix protein import in plants. In this study, we assigned a new role for AtPED2 in drought stress resistance. The transcript level of AtPED2 was downregulated by ABA and abiotic stress treatments. AtPED2 knockout mutants were insensitive to ABA-mediated seed germination, primary root elongation, and stomatal response, while AtPED2 over-expressing plants were sensitive to ABA in comparison to wide type (WT). AtPED2 also positively regulated drought stress resistance, as evidenced by the changes of water loss rate, electrolyte leakage, and survival rate. Notably, AtPED2 positively modulated expression of several stress-responsive genes (RAB18, RD22, RD29A, and RD29B), positively affected underlying antioxidant enzyme activities and negatively regulated reactive oxygen species (ROS) level under drought stress conditions. Moreover, multiple carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines were also positively regulated by AtPED2. Taken together, these results indicated a positive role for AtPED2 in drought resistance, through modulation of stress-responsive genes expression, ROS metabolism, and metabolic homeostasis, at least partially. PMID:25588806

  16. Resistance of functional Lactobacillus plantarum strains against food stress conditions.

    Science.gov (United States)

    Ferrando, Verónica; Quiberoni, Andrea; Reinhemer, Jorge; Suárez, Viviana

    2015-06-01

    The survival of three Lactobacillus plantarum strains (Lp 790, Lp 813 and Lp 998) with functional properties was studied taking into account their resistance to thermal, osmotic and oxidative stress factors. Stress treatments applied were: 52 °C-15 min (Phosphate Buffer pH 7, thermal shock), H2O2 0.1% (p/v) - 30 min (oxidative shock) and NaCl aqueous solution at 17, 25 and 30% (p/v) (room temperature - 1 h, osmotic shock). The osmotic stress was also evaluated on cell growth in MRS broth added of 2, 4, 6, 8 and 10% (p/v) of NaCl, during 20 h at 30 °C. The cell thermal adaptation was performed in MRS broth, selecting 45 °C for 30 min as final conditions for all strains. Two strains (Lp 813 and Lp 998) showed, in general, similar behaviour against the three stress factors, being clearly more resistant than Lp 790. An evident difference in growth kinetics in presence of NaCl was observed between Lp 998 and Lp 813, Lp998 showing a higher optical density (OD570nm) than Lp 813 at the end of the assay. Selected thermal adaptation improved by 2 log orders the thermal resistance of both strains, but cell growth in presence of NaCl was enhanced only in Lp 813. Oxidative resistance was not affected with this thermal pre-treatment. These results demonstrate the relevance of cell technological resistance when selecting presumptive "probiotic" cultures, since different stress factors might considerably affect viability or/and performance of the strains. The incidence of stress conditions on functional properties of the strains used in this work are currently under research in our group.

  17. Resistance of functional Lactobacillus plantarum strains against food stress conditions.

    Science.gov (United States)

    Ferrando, Verónica; Quiberoni, Andrea; Reinhemer, Jorge; Suárez, Viviana

    2015-06-01

    The survival of three Lactobacillus plantarum strains (Lp 790, Lp 813 and Lp 998) with functional properties was studied taking into account their resistance to thermal, osmotic and oxidative stress factors. Stress treatments applied were: 52 °C-15 min (Phosphate Buffer pH 7, thermal shock), H2O2 0.1% (p/v) - 30 min (oxidative shock) and NaCl aqueous solution at 17, 25 and 30% (p/v) (room temperature - 1 h, osmotic shock). The osmotic stress was also evaluated on cell growth in MRS broth added of 2, 4, 6, 8 and 10% (p/v) of NaCl, during 20 h at 30 °C. The cell thermal adaptation was performed in MRS broth, selecting 45 °C for 30 min as final conditions for all strains. Two strains (Lp 813 and Lp 998) showed, in general, similar behaviour against the three stress factors, being clearly more resistant than Lp 790. An evident difference in growth kinetics in presence of NaCl was observed between Lp 998 and Lp 813, Lp998 showing a higher optical density (OD570nm) than Lp 813 at the end of the assay. Selected thermal adaptation improved by 2 log orders the thermal resistance of both strains, but cell growth in presence of NaCl was enhanced only in Lp 813. Oxidative resistance was not affected with this thermal pre-treatment. These results demonstrate the relevance of cell technological resistance when selecting presumptive "probiotic" cultures, since different stress factors might considerably affect viability or/and performance of the strains. The incidence of stress conditions on functional properties of the strains used in this work are currently under research in our group. PMID:25790993

  18. Acid resistance and response to pH-induced stress in two Lactobacillus plantarum strains with probiotic potential.

    Science.gov (United States)

    Šeme, H; Gjuračić, K; Kos, B; Fujs, Š; Štempelj, M; Petković, H; Šušković, J; Bogovič Matijašić, B; Kosec, G

    2015-01-01

    Two new Lactobacillus plantarum strains, KR6-DSM 28780 and M5 isolated from sour turnip and traditional dried fresh cheese, respectively, were evaluated for species identity, antibiotic susceptibility, resistance to gastrointestinal conditions and adaptive response to low pH. Resistance mechanisms involved in the adaptation to acid-induced stress in these two strains were investigated by quantitative PCR of the atpA, cfa1, mleS and hisD genes. In addition to absence of antibiotic resistance, the two L. plantarum strains showed excellent survival rates at pH values as low as 2.4. Adaptive response to low pH was clearly observed in both strains; strain KR6 was superior to M5, as demonstrated by its ability to survive during 3 h incubation at pH 2.0 upon adaptation to moderately acidic conditions. In contrast, acid adaptation did not significantly affect the survival rate during simulated passage through the gastrointestinal tract. In both strains, induction of histidine biosynthesis (hisD) was upregulated during the acid adaptation response. In addition, significant upregulation of the cfa1 gene, involved in modulation of membrane fatty acid composition, was observed during the adaptation phase in strain KR6 but not in strain M5. Cells adapted to moderately acidic conditions also showed a significantly increased viability after the lyophilisation procedure, a cross-protection phenomenon providing additional advantage in probiotic application.

  19. Resistance to biotic and abiotic stresses in avena

    OpenAIRE

    Sánchez Martín, Javier

    2012-01-01

    Oat is an important grain and forage crop cultivated over than 9 million hectares globally. However, drought and biotrophic fungal diseases, such as crown rust (Puccinia coronata f. sp. avenae) and powdery mildew (Blumeria graminis f. sp. avenae) seriously threaten oat production. To combat this, agricultural scientists must develop a comprehensive understanding of the mechanisms through which plants can tolerate/resist stress and translate this to crop breeding programmes. Thu...

  20. Longevity in mice: is stress resistance a common factor?

    OpenAIRE

    Brown-Borg, H.M.

    2006-01-01

    A positive relationship between stress resistance and longevity has been reported in a multitude of studies in organisms ranging from yeast to mice. Several mouse lines have been discovered or developed that exhibit extended longevities when compared with normal, wild-type mice of the same genetic background. These long-living lines include the Ames dwarf, Snell dwarf, growth hormone receptor knockout (Laron dwarf), IGF-1 receptor heterozygote, Little, α-MUPA knockout, p66shc knockout, FIRKO,...

  1. Experimental evidence for nutrition regulated stress resistance in Drosophila ananassae.

    Directory of Open Access Journals (Sweden)

    Seema Sisodia

    Full Text Available BACKGROUND: The amount and quality of nutrients consumed by organisms have a strong impact on stress resistance, life-history traits and reproduction. The balance between energy acquisition and expenditure is crucial to the survival and reproductive success of animals. The ability of organisms to adjust their development, physiology or behavior in response to environmental conditions, called phenotypic plasticity, is a defining property of life. One of the most familiar and important examples of phenotypic plasticity is the response of stress tolerance and reproduction to changes in developmental nutrition. Larval nutrition may affect a range of different life-history traits as well as responses to environmental stress in adult. PRINCIPAL FINDINGS: Here we investigate the effect of larval nutrition on desiccation, starvation, chill-coma recovery, heat resistance as well as egg to adult viability, egg production and ovariole number in Drosophila ananassae. We raised larvae on either protein rich diet or carbohydrate rich diet. We found that flies consuming protein rich diet have higher desiccation and heat shock resistance whereas flies developed on carbohydrate rich diet have higher starvation and cold resistance. Egg production was higher in females developed on protein rich diet and we also found trade-off between egg production and Egg to adult viability of the flies. Viability was higher in carbohydrate rich diet. However, sex specific viability was found in different nutritional regimes. Higher Egg production might be due to higher ovariole number in females of protein rich diet. CONCLUSION: Thus, Drosophila ananassae adapts different stress tolerance and life-history strategies according to the quality of the available diet, which are correlated with phenotypic adjustment at anatomical and physiological levels.

  2. Effect of cold working and applied stress on the stress corrosion cracking resistance of nickel-chromium-iron alloys

    International Nuclear Information System (INIS)

    In order to grasp the stress corrosion cracking quantitative resistance of Alloys 600 and 690 in PWR primary water, the authors have studied the effect of cold working and applied stress on the stress corrosion cracking resistance of Alloys 600 and 690, in high temperature water. Stress corrosion cracking tests were conducted at 360 degrees C (633K) in a simulated PWR primary water for about 12,000 hours or 24,000 hours. From the test results, it is concluded that the stress corrosion cracking resistance in the cold worked Alloy 600 at the same applied stress level increases with an increase in cold working ratio, and the cold worked Alloys of thermally treated 690 have the excellent stress corrosion cracking resistance. Further, in this paper, the planning of stress corrosion cracking test for weld joints and weld metal of Alloy 600 is described

  3. Multi-stress resistance in Lactococcus lactis is actually escape from purine-induced stress sensitivity

    DEFF Research Database (Denmark)

    Ryssel, Mia; Hviid, Anne-Mette Meisner; Dawish, Mohamed S.;

    2014-01-01

    to the acid-stress medium increased the stress sensitivity of L. lactis MG1363. It is also shown that high intracellular guanine nucleotide pools confer increased sensitivity to high temperatures, thus showing that it is indeed a multi-stress phenotype. Our analysis suggests that an increased level......Multi-stress resistance is a widely documented and fascinating phenotype of lactococci where single mutations, preferentially in genes involved in nucleotide metabolism and phosphate uptake, result in elevated tolerance to multiple stresses simultaneously. In this report, we have analysed the...... metabolic basis behind this multi-stress-resistance phenotype in Lactococcus lactis subsp. cremoris MG1363 using acid stress as a model of multi-stress resistance. Surprisingly, we found that L. lactis MG1363 is fully resistant to pH 3.0 in the chemically defined SA medium, contrary to its sensitivity in...

  4. Resistance of oxidative stress in biofilm and planktonic cells

    Directory of Open Access Journals (Sweden)

    Witold Jakubowski

    2015-04-01

    Full Text Available This work studied the susceptibility of biofilm produced by E. coli to oxidative stress, and compared the components of free radicals defences: level of glutathione, catalase and dismutase activities in planktonic and biofilm located cells. Results showed the diversity of responses to oxidative stress in bacterial cells in log or stationary phases in both planktonic and biofilm forms. The bacteria were exposed to free-radical donors (H2O2, tBOOH, menadione, SIN-1 or peroxynitrite in a wide range of final concentrations, from 0.5 to 10mM. Different level of toxicity of individual donors, independence of cell type (planktonic forms or biofilm and phases of growth were observed. The highest oxidative stress resistance was observed for the cells in logarithmic phase of growth treated with H2O2, both in planktonic and biofilm forms, whereas for the cells in stationary phase, the highest resistance was observed for menadione. These results showed higher efficiency of agents based on superoxide anion donors in combating bacteria colonizing abiotic surfaces stainless steel (AISI 316L.

  5. l-Arginine Enhances Resistance against Oxidative Stress and Heat Stress in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Heran Ma

    2016-09-01

    Full Text Available The antioxidant properties of l-arginine (l-Arg in vivo, and its effect on enhancing resistance to oxidative stress and heat stress in Caenorhabditis elegans were investigated. C. elegans, a worm model popularly used in molecular and developmental biology, was used in the present study. Here, we report that l-Arg, at a concentration of 1 mM, prolonged C. elegans life by 26.98% and 37.02% under oxidative and heat stress, respectively. Further experiments indicated that the longevity-extending effects of l-Arg may be exerted by its free radical scavenging capacity and the upregulation of aging-associated gene expression in worms. This work is important in the context of numerous recent studies that concluded that environment stresses are associated with an increased population death rate.

  6. Oxidative stress, insulin resistance, dyslipidemia and type 2diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Surapon Tangvarasittichai

    2015-01-01

    Oxidative stress is increased in metabolic syndromeand type 2 diabetes mellitus (T2DM) and this appearsto underlie the development of cardiovascular disease,T2DM and diabetic complications. Increased oxidativestress appears to be a deleterious factor leading to insulin resistance, dyslipidemia, β-cell dysfunction, impaired glucose tolerance and ultimately leading to T2DM. Chronic oxidative stress, hyperglycemia and dyslipidemia are particularly dangerous for β-cells from lowest levels of antioxidant, have high oxidative energy requirements, decrease the gene expression of key β-cell genes and induce cell death. If β-cell functioning is impaired, it results in an under production of insulin, impairs glucose stimulated insulin secretion, fasting hyperglycemia and eventually the development of T2DM.

  7. Oxidative Stress: A Potential Recipe For Anxiety, Hypertension and Insulin Resistance

    OpenAIRE

    Salim, Samina; Asghar, Mohammad; Chugh, Gaurav; Taneja, Manish; Xia, Zhilian; Saha, Kaustav

    2010-01-01

    We recently reported involvement of oxidative stress in anxiety-like behavior of rats. Others in separate studies have demonstrated a link between oxidative stress and hypertension as well as with type 2 diabetes/insulin resistance. In the present study, we have tested a putative role of oxidative stress in anxiety-like behavior, hypertension and insulin resistance using a rat model of oxidative stress. Oxidative stress in rats was produced by xanthine (0.1%; drinking water) and xanthine oxid...

  8. Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism.

    Science.gov (United States)

    Kissoudis, Christos; Sunarti, Sri; van de Wiel, Clemens; Visser, Richard G F; van der Linden, C Gerard; Bai, Yuling

    2016-09-01

    Stress conditions in agricultural ecosystems can occur at variable intensities. Different resistance mechanisms against abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of different levels of salt stress ranging from mild to severe (50, 100, and 150mM NaCl) on powdery mildew resistance and overall performance of tomato introgression lines with contrasting levels of partial resistance, as well as near-isogenic lines (NILs) carrying the resistance gene Ol-1 (associated with a slow hypersensitivity response; HR), ol-2 (an mlo mutant associated with papilla formation), and Ol-4 (an R gene associated with a fast HR). Powdery mildew resistance was affected by salt stress in a genotype- and stress intensity-dependent manner. In susceptible and partial resistant lines, increased susceptibility was observed under mild salt stress (50mM) which was accompanied by accelerated cell death-like senescence. In contrast, severe salt stress (150mM) reduced disease symptoms. Na(+) and Cl(-) accumulation in the leaves was linearly related to the decreased pathogen symptoms under severe stress. In contrast, complete resistance mediated by ol-2 and Ol-4 was unaffected under all treatment combinations, and was associated with a decreased growth penalty. Increased susceptibility and senescence under combined stress in NIL-Ol-1 was associated with the induction of ethylene and jasmonic acid pathway genes and the cell wall invertase gene LIN6. These results highlight the significance of stress severity and resistance type on the plant's performance under the combination of abiotic and biotic stress.

  9. Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism.

    Science.gov (United States)

    Kissoudis, Christos; Sunarti, Sri; van de Wiel, Clemens; Visser, Richard G F; van der Linden, C Gerard; Bai, Yuling

    2016-09-01

    Stress conditions in agricultural ecosystems can occur at variable intensities. Different resistance mechanisms against abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of different levels of salt stress ranging from mild to severe (50, 100, and 150mM NaCl) on powdery mildew resistance and overall performance of tomato introgression lines with contrasting levels of partial resistance, as well as near-isogenic lines (NILs) carrying the resistance gene Ol-1 (associated with a slow hypersensitivity response; HR), ol-2 (an mlo mutant associated with papilla formation), and Ol-4 (an R gene associated with a fast HR). Powdery mildew resistance was affected by salt stress in a genotype- and stress intensity-dependent manner. In susceptible and partial resistant lines, increased susceptibility was observed under mild salt stress (50mM) which was accompanied by accelerated cell death-like senescence. In contrast, severe salt stress (150mM) reduced disease symptoms. Na(+) and Cl(-) accumulation in the leaves was linearly related to the decreased pathogen symptoms under severe stress. In contrast, complete resistance mediated by ol-2 and Ol-4 was unaffected under all treatment combinations, and was associated with a decreased growth penalty. Increased susceptibility and senescence under combined stress in NIL-Ol-1 was associated with the induction of ethylene and jasmonic acid pathway genes and the cell wall invertase gene LIN6. These results highlight the significance of stress severity and resistance type on the plant's performance under the combination of abiotic and biotic stress. PMID:27436279

  10. Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism

    NARCIS (Netherlands)

    Kissoudis, Christos; Sri Sunarti, Sri; De Wiel, Van Clemens; Visser, Richard G.F.; Linden, van der Gerard; Bai, Yuling

    2016-01-01

    Stress conditions in agricultural ecosystems can occur at variable intensities. Different resistance mechanisms against abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effec

  11. Supplementary data: Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and mechanism of resistance

    NARCIS (Netherlands)

    Kissoudis, C.; Sri Sunarti, Sri; Wiel, van de C.C.M.; Visser, R.G.F.; Linden, van der C.G.; Bai, Y.

    2016-01-01

    Stress conditions in agricultural ecosystems can occur in variable intensities. Different resistance mechanisms to abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of

  12. Cellular memory of acquired stress resistance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Guan, Qiaoning; Haroon, Suraiya; Bravo, Diego González; Will, Jessica L; Gasch, Audrey P

    2012-10-01

    Cellular memory of past experiences has been observed in several organisms and across a variety of experiences, including bacteria "remembering" prior nutritional status and amoeba "learning" to anticipate future environmental conditions. Here, we show that Saccharomyces cerevisiae maintains a multifaceted memory of prior stress exposure. We previously demonstrated that yeast cells exposed to a mild dose of salt acquire subsequent tolerance to severe doses of H(2)O(2). We set out to characterize the retention of acquired tolerance and in the process uncovered two distinct aspects of cellular memory. First, we found that H(2)O(2) resistance persisted for four to five generations after cells were removed from the prior salt treatment and was transmitted to daughter cells that never directly experienced the pretreatment. Maintenance of this memory did not require nascent protein synthesis after the initial salt pretreatment, but rather required long-lived cytosolic catalase Ctt1p that was synthesized during salt exposure and then distributed to daughter cells during subsequent cell divisions. In addition to and separable from the memory of H(2)O(2) resistance, these cells also displayed a faster gene-expression response to subsequent stress at >1000 genes, representing transcriptional memory. The faster gene-expression response requires the nuclear pore component Nup42p and serves an important function by facilitating faster reacquisition of H(2)O(2) tolerance after a second cycle of salt exposure. Memory of prior stress exposure likely provides a significant advantage to microbial populations living in ever-changing environments. PMID:22851651

  13. β-氨基丁酸诱导水稻稻瘟病抗性对活性氧代谢的影响%Effects of β-Amino Butyric Acid Induced Rice Blast Resistance on Reactive Oxygen Metabolism

    Institute of Scientific and Technical Information of China (English)

    李莉; 郭晓丽; 刘晓梅; 温嘉伟; 张秀容; 孙辉; 赵宇; 任金平

    2009-01-01

    [Objective] This study was to understand the effects of β-Amino butyric acid(abbreviated as BABA) induced rice blast resistance on reactive oxygen metabolism. [Method] Using the cultivar Chaochan 2 that is highly susceptible to disease as experimental material, the changes of catalase(CAT), and superoxide dismutase(SOD) and MDA activities in rice treated by BABA were investigated. [Result] In rice plants treated by BABA, the activities of CAT and SOD increased, meanwhile the MDA content also rose to some extent, resulting in the disease resistance to rice blast. [Conclusion] By influencing reactive oxygen metabolism, BABA endows rice plants with resistance to rice blast. BABA is safe to environment and has highly resistance-inducing capacity, it could be generalized in production.

  14. Stressful life events are associated with insulin resistance among Chinese immigrant women in the United States

    Directory of Open Access Journals (Sweden)

    Carolyn Y. Fang

    2015-01-01

    Conclusions: This is one of the first studies to examine the associations between psychosocial stress and insulin resistance in Chinese immigrant women. These findings contribute to a growing body of literature on stress and diabetes risk in an immigrant population.

  15. Role of oxidative stress in endothelial insulin resistance

    Institute of Scientific and Technical Information of China (English)

    Francesco Paneni; Sarah Costantino; Francesco Cosentino

    2015-01-01

    The International Diabetes Federation estimates that 316 million people are currently affected by impaired glucose tolerance (IGT). Most importantly, recent forecasts anticipate a dramatic IGT increase with more that 470 million people affected by the year 2035. Impaired insulin sensitivity is major feature of obesity and diabetes and is strongly linked with adverse cardiometabolic phenotypes. However, the etiologic pathway linking impaired glucose tolerance and cardiovascular disease remains to be deciphered. Although insulin resistance has been attributed to inflammatory programs starting in adipose tissue, emerging evidence indicates thatendothelial dysfunction may represent the upstreamevent preceding peripheral impairment of insulinsensitivity. Indeed, suppression of reactive oxygenspecies-dependent pathways in the endothelium hasshown to restore insulin delivery to peripheral organsby preserving nitric oxide (NO) availability. Here wedescribe emerging theories concerning endothelialinsulin resistance, with particular emphasis on the roleoxidative stress. Complex molecular circuits includingendothelial nitric oxide synthase, prostacyclin synthase,mitochondrial adaptor p66Shc, nicotinamide adeninedinucleotide phosphate-oxidase oxidase and nuclearfactor kappa-B are discussed. Moreover, the reviewprovides insights on the effectiveness of availablecompounds (i.e. , ruboxistaurin, sildenafil, endothelinreceptor antagonists, NO donors) in restoring endothelialinsulin signalling. Taken together, these aspects maysignificantly contribute to design novel therapeuticapproaches to restore glucose homeostasis in patientswith obesity and diabetes.

  16. Geographic variation for climatic stress resistance traits in the sprintail Orchesella cincta

    DEFF Research Database (Denmark)

    Bahrndorff, Simon; Holmstrup, Martin; Petersen, H.;

    2006-01-01

    Multiple traits of stress resistance were investigated in the epedaphic springtail Orchesella cincta. Second generation adults from five laboratory populations were compared with respect to resistance to extreme temperatures and desiccation, and traits relevant to climatic adaptation. Populations...... in stress resistance of springtails related to climatic conditions. Keywords: Geographic variation; Climatic change; Adaptation; Orchesella cincta; Soil ecosystems......Multiple traits of stress resistance were investigated in the epedaphic springtail Orchesella cincta. Second generation adults from five laboratory populations were compared with respect to resistance to extreme temperatures and desiccation, and traits relevant to climatic adaptation. Populations...... desiccation resistant than males. The results of cold shock resistance showed a positive increase with lowest environmental temperature recorded at the sites of population origin, whereas heat shock resistance showed a positive increase with highest recorded temperature at the sites of population origin...

  17. Mechanisms of Stress Resistance and Gene Regulation in the Radioresistant Bacterium Deinococcus radiodurans.

    Science.gov (United States)

    Agapov, A A; Kulbachinskiy, A V

    2015-10-01

    The bacterium Deinococcus radiodurans reveals extraordinary resistance to ionizing radiation, oxidative stress, desiccation, and other damaging conditions. In this review, we consider the main molecular mechanisms underlying such resistance, including the action of specific DNA repair and antioxidation systems, and transcription regulation during the anti-stress response.

  18. Expression of the Grape VqSTS21 Gene in Arabidopsis Confers Resistance to Osmotic Stress and Biotrophic Pathogens but Not Botrytis cinerea

    Science.gov (United States)

    Huang, Li; Zhang, Songlin; Singer, Stacy D.; Yin, Xiangjing; Yang, Jinhua; Wang, Yuejin; Wang, Xiping

    2016-01-01

    Stilbene synthase (STS) is a key gene in the biosynthesis of various stilbenoids, including resveratrol and its derivative glucosides (such as piceid), that has been shown to contribute to disease resistance in plants. However, the mechanism behind such a role has yet to be elucidated. Furthermore, the function of STS genes in osmotic stress tolerance remains unclear. As such, we sought to elucidate the role of STS genes in the defense against biotic and abiotic stress in the model plant Arabidopsis thaliana. Expression profiling of 31 VqSTS genes from Vitis quinquangularis revealed that VqSTS21 was up-regulated in response to powdery mildew (PM) infection. To provide a deeper understanding of the function of this gene, we cloned the full-length coding sequence of VqSTS21 and overexpressed it in Arabidopsis thaliana via Agrobacterium-mediated transformation. The resulting VqSTS21 Arabidopsis lines produced trans-piceid rather than resveratrol as their main stilbenoid product and exhibited improved disease resistance to PM and Pseudomonas syringae pv. tomato DC3000, but displayed increased susceptibility to Botrytis cinerea. In addition, transgenic Arabidopsis lines were found to confer tolerance to salt and drought stress from seed germination through plant maturity. Intriguingly, qPCR assays of defense-related genes involved in salicylic acid, jasmonic acid, and abscisic acid-induced signaling pathways in these transgenic lines suggested that VqSTS21 plays a role in various phytohormone-related pathways, providing insight into the mechanism behind VqSTS21-mediated resistance to biotic and abiotic stress. PMID:27695466

  19. Mefenamic Acid Induced Nephrotoxicity: An Animal Model

    Directory of Open Access Journals (Sweden)

    Muhammad Nazrul Somchit

    2014-12-01

    Full Text Available Purpose: Nonsteroidal anti-inflammatory drugs (NSAIDs are used for the treatment of many joint disorders, inflammation and to control pain. Numerous reports have indicated that NSAIDs are capable of producing nephrotoxicity in human. Therefore, the objective of this study was to evaluate mefenamic acid, a NSAID nephrotoxicity in an animal model. Methods: Mice were dosed intraperitoneally with mefenamic acid either as a single dose (100 or 200 mg/kg in 10% Dimethyl sulfoxide/Palm oil or as single daily doses for 14 days (50 or 100 mg/kg in 10% Dimethyl sulfoxide/Palm oil per day. Venous blood samples from mice during the dosing period were taken prior to and 14 days post-dosing from cardiac puncture into heparinized vials. Plasma blood urea nitrogen (BUN and creatinine activities were measured. Results: Single dose of mefenamic acid induced mild alteration of kidney histology mainly mild glomerular necrosis and tubular atrophy. Interestingly, chronic doses induced a dose dependent glomerular necrosis, massive degeneration, inflammation and tubular atrophy. Plasma blood urea nitrogen was statistically elevated in mice treated with mefenamic acid for 14 days similar to plasma creatinine. Conclusion: Results from this study suggest that mefenamic acid as with other NSAIDs capable of producing nephrotoxicity. Therefore, the study of the exact mechanism of mefenamic acid induced severe nephrotoxicity can be done in this animal model.

  20. Relationship Between Physiological-biochemical Changes Under Drought Stress and Drought Resistance in Ramie

    Institute of Scientific and Technical Information of China (English)

    JIE Yu-cheng; HUANG Pi-sheng; LI Zong-dao

    2001-01-01

    A study on the physiological-biochemical changes of different ramie(Boehmeria Jacq. ) varieties under drought stress was carried out, the results showed that relative water contents(RWC) decreased and RPP increased with the increase of drought stress. Compared with drought sensitive varieties, drought resistant varieties had higher RWC in leaves but lower RPP. Peroxidase activity of drought-resistance varieties changed from low to high whereas sensitive ones changed in opposite direction. Proline contents of drought sensitive varieties was higher than those of drought resistant ones under a certain degree drought stress. Proline accumulation in drought resistant varieties was faster than that in drought sensitive ones under serious drought stress.MDA contents in leaf was increased under drought stress. MDA contents increased slowly in resistant varieties while that increased rapidly in sensitive ones.

  1. Effect of cold working on the stress corrosion cracking resistance of nickel-chromium-iron alloys

    International Nuclear Information System (INIS)

    In order to grasp the stress corrosion cracking resistance of cold worked nickel base alloys in PWR primary water, the effect of cold working on the stress corrosion cracking resistance of alloys 600, X-750 and 690, in high temperature water, have been studied. Stress corrosion cracking tests were conducted at 3600C (633K) in a simulated PWR primary water for about 12,000 hours (43.2Ms). From the test results, it is concluded that the stress corrosion cracking resistance in the cold worked Alloy 600 at the same applied stress level increases with an increase in cold working ratio, and the cold worked alloys of thermally treated 690 and X-750 have excellent stress corrosion cracking resistance. (Author)

  2. Angiotensin II Receptor Blocker Ameliorates Stress-Induced Adipose Tissue Inflammation and Insulin Resistance

    OpenAIRE

    Motoharu Hayashi; Kyosuke Takeshita; Yasuhiro Uchida; Koji Yamamoto; Ryosuke Kikuchi; Takayuki Nakayama; Emiko Nomura; Xian Wu Cheng; Tadashi Matsushita; Shigeo Nakamura; Toyoaki Murohara

    2014-01-01

    A strong causal link exists between psychological stress and insulin resistance as well with hypertension. Meanwhile, stress-related responses play critical roles in glucose metabolism in hypertensive patients. As clinical trials suggest that angiotensin-receptor blocker delays the onset of diabetes in hypertensive patients, we investigated the effects of irbesartan on stress-induced adipose tissue inflammation and insulin resistance. C57BL/6J mice were subjected to 2-week intermittent restra...

  3. Salt stress in maize: effects, resistance mechanisms, and management. A review

    OpenAIRE

    Farooq, Muhammad; Hussain, Mubshar; Wakeel, Abdul; Kadambot H M Siddique

    2015-01-01

    Maize is grown under a wide spectrum of soil and climatic conditions. Maize is moderately sensitive to salt stress; therefore, soil salinity is a serious threat to its production worldwide. Understanding maize response to salt stress and resistance mechanisms and overviewing management options may help to devise strategies for improved maize performance in saline environments. Here, we reviewed the effects, resistance mechanisms, and management of salt stress in maize. Our main conclusions ar...

  4. Higher in vitro resistance to oxidative stress in extra-pair offspring.

    Science.gov (United States)

    Losdat, S; Helfenstein, F; Saladin, V; Richner, H

    2011-11-01

    Oxidative stress is considered to act as a universal physiological constraint in life-history evolution of animals. This should be of interest for extra-pair paternity behaviour, and we tested here the prediction that offspring arising from extra-pair matings of female great tits show higher resistance to oxidative stress than within-pair offspring. Resistance to oxidative stress, measured as the whole blood resistance to a controlled free-radical attack, was significantly higher for extra-pair offspring as predicted although these were not heavier or in better body condition than within-pair offspring. Since resistance to oxidative stress has been suggested to enhance survival and reproductive rates, extra-pair offspring with superior resistance to oxidative stress, be it through maternal effects or paternal inheritance, may achieve higher fitness and thus provide significant indirect fitness benefits to their mothers. In addition, because oxidative stress affects colour signals and sperm traits, females may also gain fitness benefits by producing sons that are more attractive (sexy-sons hypothesis) and have sperm of superior quality (sexy-sperm hypothesis). Heritability of resistance to oxidative stress as well as maternal effects may both act as proximate mechanisms for the observed result. Disentangling these two mechanisms would require an experimental approach. Future long-term studies should also aim at experimentally testing whether higher resistance to oxidative stress of EP nestlings indeed translates into fitness benefits to females. PMID:21899636

  5. The effect of acute mental stress on limb vasodilation is unrelated to total peripheral resistance

    NARCIS (Netherlands)

    N.J. Paine; C. Ring; J.A. Bosch; D. McIntyre; J.J.C.S. Veldhuijzen van Zanten

    2013-01-01

    Mental stress can trigger myocardial infarction, with poor vascular responses to stress implicated as a pathway. Vascular stress reactivity can be assessed by different methods, such as total peripheral resistance (TPR) and forearm blood flow (FBF). Little is known about how these vascular assessmen

  6. Low dose of oleanolic acid protects against lithocholic acid-induced cholestasis in mice: potential involvement of nuclear factor-E2-related factor 2-mediated upregulation of multidrug resistance-associated proteins.

    Science.gov (United States)

    Chen, Pan; Zeng, Hang; Wang, Yongtao; Fan, Xiaomei; Xu, Chenshu; Deng, Rongrong; Zhou, Xunian; Bi, Huichang; Huang, Min

    2014-05-01

    Oleanolic acid (OA) is a natural triterpenoid and has been demonstrated to protect against varieties of hepatotoxicants. Recently, however, OA at high doses was reported to produce apparent cholestasis in mice. In this study, we characterized the protective effect of OA at low doses against lithocholic acid (LCA)-induced cholestasis in mice and explored further mechanisms. OA cotreatment (5, 10, and 20 mg/kg, i.p.) significantly improved mouse survival rate, attenuated liver necrosis, and decreased serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase; more importantly, serum total bile acids and bilirubin, as well as hepatic total bile acids were also remarkably reduced. Gene and protein expression analysis showed that hepatic expression of multidrug resistance-associated protein 2 (Mrp2), Mrp3, and Mrp4 was significantly increased by OA cotreatment, whereas other bile acid metabolism- and transport-related genes, including Na+/taurocholate cotransporter, organic anion transporter 1b2, bile salt export pump, multidrug resistance protein 3, Cyp3a11, Cyp2b10, Sulfotransferase 2a1 (Sult2a1), and UDP-glucuronosyltransferase 1a1 (Ugt1a1), were only slightly changed. OA also caused increased nuclear factor-E2-related factor (Nrf2) mRNA expression and nuclear protein accumulation, whereas nuclear receptors farnesoid X receptor (FXR), pregnane X receptor (PXR), and constitutive androstane receptor were not significantly influenced by OA. Luciferase (Luc) assays performed in HepG2 cells illustrated that OA was a strong Nrf2 agonist with moderate PXR and weak FXR agonism. Finally, in mouse primary cultured hepatocytes, OA dose- and time-dependently induced expression of Mrp2, Mrp3, and Mrp4; however, this upregulation was abrogated when Nrf2 was silenced. In conclusion, OA produces a protective effect against LCA-induced hepatotoxicity and cholestasis, possibly due to Nrf2-mediated upregulation of Mrp2, Mrp3, and Mrp4. PMID:24510383

  7. Induced resistance in tomato by SAR activators during predisposing salinity stress

    Directory of Open Access Journals (Sweden)

    Matthew Francis Pye

    2013-05-01

    Full Text Available Plant activators are chemicals that induce disease resistance. The phytohormone salicylic acid (SA is a crucial signal for systemic acquired resistance (SAR, and SA-mediated resistance is a target of several commercial plant activators, including Actigard (1,2,3-benzothiadiazole-7-thiocarboxylic acid-s-methyl-ester, BTH and Tiadinil (N-(3-chloro-4-methylphenyl-4-methyl-1,2,3-thiadiazole-5-carboxamide, TDL. BTH and TDL were examined for their impact on abscisic acid (ABA-mediated, salt-induced disease predisposition in tomato seedlings. A brief episode of salt stress to roots significantly increased the severity of disease caused by Pseudomonas syringae pv. tomato (Pst and Phytophthora capsici relative to non-stressed plants. Root treatment with TDL induced resistance to Pst in leaves and provided protection in both non-stressed and salt-stressed seedlings in WT and highly susceptible NahG plants. Non-stressed and salt-stressed ABA-deficient sitiens mutants were highly resistant to Pst. Neither TDL nor BTH induced resistance to root infection by P. capsici, nor did they moderate the salt-induced increment in disease severity. Root treatment with these plant activators increased the levels of ABA in roots and shoots similar to levels observed in salt-stressed plants. The results indicate that SAR activators can protect tomato plants from bacterial speck disease under predisposing salt stress, and suggest that some SA-mediated defense responses function sufficiently in plants with elevated levels of ABA.

  8. Genome-wide association analysis of oxidative stress resistance in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Allison L Weber

    Full Text Available BACKGROUND: Aerobic organisms are susceptible to damage by reactive oxygen species. Oxidative stress resistance is a quantitative trait with population variation attributable to the interplay between genetic and environmental factors. Drosophila melanogaster provides an ideal system to study the genetics of variation for resistance to oxidative stress. METHODS AND FINDINGS: We used 167 wild-derived inbred lines of the Drosophila Genetic Reference Panel for a genome-wide association study of acute oxidative stress resistance to two oxidizing agents, paraquat and menadione sodium bisulfite. We found significant genetic variation for both stressors. Single nucleotide polymorphisms (SNPs associated with variation in oxidative stress resistance were often sex-specific and agent-dependent, with a small subset common for both sexes or treatments. Associated SNPs had moderately large effects, with an inverse relationship between effect size and allele frequency. Linear models with up to 12 SNPs explained 67-79% and 56-66% of the phenotypic variance for resistance to paraquat and menadione sodium bisulfite, respectively. Many genes implicated were novel with no known role in oxidative stress resistance. Bioinformatics analyses revealed a cellular network comprising DNA metabolism and neuronal development, consistent with targets of oxidative stress-inducing agents. We confirmed associations of seven candidate genes associated with natural variation in oxidative stress resistance through mutational analysis. CONCLUSIONS: We identified novel candidate genes associated with variation in resistance to oxidative stress that have context-dependent effects. These results form the basis for future translational studies to identify oxidative stress susceptibility/resistance genes that are evolutionary conserved and might play a role in human disease.

  9. A shift to organismal stress resistance in programmed cell death mutants.

    Directory of Open Access Journals (Sweden)

    Meredith E Judy

    Full Text Available Animals have many ways of protecting themselves against stress; for example, they can induce animal-wide, stress-protective pathways and they can kill damaged cells via apoptosis. We have discovered an unexpected regulatory relationship between these two types of stress responses. We find that C. elegans mutations blocking the normal course of programmed cell death and clearance confer animal-wide resistance to a specific set of environmental stressors; namely, ER, heat and osmotic stress. Remarkably, this pattern of stress resistance is induced by mutations that affect cell death in different ways, including ced-3 (cell death defective mutations, which block programmed cell death, ced-1 and ced-2 mutations, which prevent the engulfment of dying cells, and progranulin (pgrn-1 mutations, which accelerate the clearance of apoptotic cells. Stress resistance conferred by ced and pgrn-1 mutations is not additive and these mutants share altered patterns of gene expression, suggesting that they may act within the same pathway to achieve stress resistance. Together, our findings demonstrate that programmed cell death effectors influence the degree to which C. elegans tolerates environmental stress. While the mechanism is not entirely clear, it is intriguing that animals lacking the ability to efficiently and correctly remove dying cells should switch to a more global animal-wide system of stress resistance.

  10. Identification of plant genes for abiotic stress resistance

    NARCIS (Netherlands)

    Dixit, S.A.

    2008-01-01

    As water and salt stresses occur frequently and can affect many habitats, plants have developed several strategies to cope with these challenges: either adaptation mechanisms, which allow them to survive the adverse conditions, or specific growth habits to avoid stress conditions. Stress-tolerant pl

  11. [Lipid composition in erythrocytic membranes of rats with various stress resistance during repeated immobilization].

    Science.gov (United States)

    Tsygvintsev, A A; Bryndina, I G

    2011-01-01

    The dependence between variation of erythrocyte phospholipid composition and stress resistance was studied in chronic experiment on nonline male albino rats, previously differed by their behavior in the 'open field' test. A significant exhausting of membrane pool by the basic classes of phospholipids was registered under influence of 2 hours daily immobilization during 5, 10, 20, 30 days, however, their metabolism for resistant and predisposed to stress animals flows variously. PMID:21688664

  12. Decreased Skin-Mediated Detoxification Contributes to Oxidative Stress and Insulin Resistance

    OpenAIRE

    Xing-Xing Liu; Chang-Bin Sun; Ting-Tong Yang; Da Li; Chun-Yan Li; Yan-Jie Tian; Ming Guo; Yu Cao; Shi-Sheng Zhou

    2012-01-01

    The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Ra...

  13. Fatty-acid metabolism is involved in stress-resistance mechanisms of Caenorhabditis elegans

    OpenAIRE

    Horikawa, Makoto; Sakamoto, Kazuichi

    2009-01-01

    Fatty acids are the major components of the phospholipid bilayer and are involved in several functions of cell membrane. We previously reported that fatty-acid metabolism is involved in the regulation of DAF-2/insulin signal in Caenorhabditis elegans. In this study, we investigate the role of fatty-acid metabolism in stress resistance with respect to daf-16 in nematode. We found that fatty-acid metabolism regulates heat, osmotic, and oxidative-stress resistance in C. elegans. RNA interference...

  14. Learning during middle age: A resistance to stress?

    OpenAIRE

    Hodes, Georgia E; Shors, Tracey J.

    2006-01-01

    Acute stressful experience enhances subsequent learning in males and impairs learning in females. These sex differences emerge soon after puberty in adulthood. Whether these opposite effects of stress on learning extend into older age is unknown. To examine this, young adult (2–3 months) and middle aged (17–18 months) Fischer 344 rats of both sexes were exposed to an acute stress or of brief tail shocks and trained 24 h later with classical eyeblink conditioning using a trace paradigm. Wherea...

  15. Heat-resistant protein expression during germination of maize seeds under water stress.

    Science.gov (United States)

    Abreu, V M; Silva Neta, I C; Von Pinho, E V R; Naves, G M F; Guimarães, R M; Santos, H O; Von Pinho, R G

    2016-01-01

    Low water availability is one of the factors that limit agricultural crop development, and hence the development of genotypes with increased water stress tolerance is a challenge in plant breeding programs. Heat-resistant proteins have been widely studied, and are reported to participate in various developmental processes and to accumulate in response to stress. This study aimed to evaluate heat-resistant protein expression under water stress conditions during the germination of maize seed inbreed lines differing in their water stress tolerance. Maize seed lines 91 and 64 were soaked in 0, -0.3, -0.6, and -0.9 MPa water potential for 0, 6, 12, 18, and 24 h. Line 91 is considered more water stress-tolerant than line 64. The analysis of heat-resistant protein expression was made by gel electrophoresis and spectrophotometry. In general, higher expression of heat-resistant proteins was observed in seeds from line 64 subjected to shorter soaking periods and lower water potentials. However, in the water stress-tolerant line 91, a higher expression was observed in seeds that were subjected to -0.3 and -0.6 MPa water potentials. In the absence of water stress, heat-resistant protein expression was reduced with increasing soaking period. Thus, there was a difference in heat-resistant protein expression among the seed lines differing in water stress tolerance. Increased heat-resistant protein expression was observed in seeds from line 91 when subjected to water stress conditions for longer soaking periods. PMID:27525950

  16. Minocycline ameliorates prenatal valproic acid induced autistic behaviour, biochemistry and blood brain barrier impairments in rats.

    Science.gov (United States)

    Kumar, Hariom; Sharma, Bhupesh

    2016-01-01

    Autism is a neurodevelopment disorder. One percent worldwide population suffers with autism and males suffer more than females. Microglia plays an important role in neurodevelopment, neuropsychiatric and neurodegenerative disorders. The present study has been designed to investigate the role of minocycline in prenatal valproic acid induced autism in rats. Animals with prenatal valproic acid have reduced social interaction (three chamber social behaviour apparatus), spontaneous alteration (Y-Maze), exploratory activity (Hole board test), intestinal motility, serotonin levels (both in prefrontal cortex and ileum) and prefrontal cortex mitochondrial complex activity (complexes I, II, IV). Furthermore, prenatal valproic acid treated animals have shown an increase in locomotion (actophotometer), anxiety (elevated plus maze), brain oxidative stress (thiobarbituric acid reactive species, glutathione, catalase), nitrosative stress (nitrite/nitrate), inflammation (both in brain and ileum myeloperoxidase activity), calcium and blood brain barrier permeability. Treatment with minocycline significantly attenuated prenatal valproic acid induced reduction in social interaction, spontaneous alteration, exploratory activity intestinal motility, serotonin levels and prefrontal cortex mitochondrial complex activity. Furthermore, minocycline has also attenuated prenatal valproic acid induced increase in locomotion, anxiety, brain oxidative and nitrosative stress, inflammation, calcium and blood brain barrier permeability. Thus, it may be concluded that prenatal valproic acid has induced autistic behaviour, biochemistry and blood brain barrier impairment in animals, which were significantly attenuated by minocycline. Minocycline should be explored further for its therapeutic benefits in autism.

  17. Minocycline ameliorates prenatal valproic acid induced autistic behaviour, biochemistry and blood brain barrier impairments in rats.

    Science.gov (United States)

    Kumar, Hariom; Sharma, Bhupesh

    2016-01-01

    Autism is a neurodevelopment disorder. One percent worldwide population suffers with autism and males suffer more than females. Microglia plays an important role in neurodevelopment, neuropsychiatric and neurodegenerative disorders. The present study has been designed to investigate the role of minocycline in prenatal valproic acid induced autism in rats. Animals with prenatal valproic acid have reduced social interaction (three chamber social behaviour apparatus), spontaneous alteration (Y-Maze), exploratory activity (Hole board test), intestinal motility, serotonin levels (both in prefrontal cortex and ileum) and prefrontal cortex mitochondrial complex activity (complexes I, II, IV). Furthermore, prenatal valproic acid treated animals have shown an increase in locomotion (actophotometer), anxiety (elevated plus maze), brain oxidative stress (thiobarbituric acid reactive species, glutathione, catalase), nitrosative stress (nitrite/nitrate), inflammation (both in brain and ileum myeloperoxidase activity), calcium and blood brain barrier permeability. Treatment with minocycline significantly attenuated prenatal valproic acid induced reduction in social interaction, spontaneous alteration, exploratory activity intestinal motility, serotonin levels and prefrontal cortex mitochondrial complex activity. Furthermore, minocycline has also attenuated prenatal valproic acid induced increase in locomotion, anxiety, brain oxidative and nitrosative stress, inflammation, calcium and blood brain barrier permeability. Thus, it may be concluded that prenatal valproic acid has induced autistic behaviour, biochemistry and blood brain barrier impairment in animals, which were significantly attenuated by minocycline. Minocycline should be explored further for its therapeutic benefits in autism. PMID:26551768

  18. Severe Injury Is Associated With Insulin Resistance, Endoplasmic Reticulum Stress Response, and Unfolded Protein Response

    Science.gov (United States)

    Jeschke, Marc G.; Finnerty, Celeste C.; Herndon, David N.; Song, Juquan; Boehning, Darren; Tompkins, Ronald G.; Baker, Henry V.; Gauglitz, Gerd G.

    2012-01-01

    Objective We determined whether postburn hyperglycemia and insulin resistance are associated with endoplasmic reticulum (ER) stress/unfolded protein response (UPR) activation leading to impaired insulin receptor signaling. Background Inflammation and cellular stress, hallmarks of severely burned and critically ill patients, have been causally linked to insulin resistance in type 2 diabetes via induction of ER stress and the UPR. Methods Twenty severely burned pediatric patients were compared with 36 nonburned children. Clinical markers, protein, and GeneChip analysis were used to identify transcriptional changes in ER stress and UPR and insulin resistance–related signaling cascades in peripheral blood leukocytes, fat, and muscle at admission and up to 466 days postburn. Results Burn-induced inflammatory and stress responses are accompanied by profound insulin resistance and hyperglycemia. Genomic and protein analysis revealed that burn injury was associated with alterations in the signaling pathways that affect insulin resistance, ER/sarcoplasmic reticulum stress, inflammation, and cell growth/apoptosis up to 466 days postburn. Conclusion Burn-induced insulin resistance is associated with persistent ER/sarcoplasmic reticulum stress/UPR and subsequent suppressed insulin receptor signaling over a prolonged period of time. PMID:22241293

  19. Endoplasmic reticulum stress regulates inflammation and insulin resistance in skeletal muscle from pregnant women.

    Science.gov (United States)

    Liong, Stella; Lappas, Martha

    2016-04-15

    Sterile inflammation and infection are key mediators of inflammation and peripheral insulin resistance associated with gestational diabetes mellitus (GDM). Studies have shown endoplasmic reticulum (ER) stress to induce inflammation and insulin resistance associated with obesity and type 2 diabetes, however is paucity of studies investigating the effects of ER stress in skeletal muscle on inflammation and insulin resistance associated with GDM. ER stress proteins IRE1α, GRP78 and XBP-1s were upregulated in skeletal muscle of obese pregnant women, whereas IRE1α was increased in GDM women. Suppression of ER stress, using ER stress inhibitor tauroursodeoxycholic acid (TUDCA) or siRNA knockdown of IRE1α and GRP78, significantly downregulated LPS-, poly(I:C)- or IL-1β-induced production of IL-6, IL-8, IL-1β and MCP-1. Furthermore, LPS-, poly(I:C)- or TNF-α-induced insulin resistance was improved following suppression of ER stress, by increasing insulin-stimulated phosphorylation of IR-β, IRS-1, GLUT-4 expression and glucose uptake. In summary, our inducible obesity and GDM-like models suggests that the development of GDM may be involved in activating ER stress-induced inflammation and insulin resistance in human skeletal muscle. PMID:26902174

  20. Ecogenomics of plant resistance to biotic and abiotic stresses

    NARCIS (Netherlands)

    Davila Olivas, N.H.

    2016-01-01

    Summary

    In natural and agricultural ecosystems, plants are exposed to a wide diversity of abiotic and biotic stresses such as drought, salinity, pathogens and insect herbivores. Under natural conditions, these stresses do not occur in isolation but commonly occur simultaneo

  1. Aging related ER stress is not responsible for anabolic resistance in mouse skeletal muscle

    NARCIS (Netherlands)

    S. Chalil; N. Pierre; A.D. Bakker; R.J. Manders; A. Pletsers; M. Francaux; J. Klein-Nulend; R.T. Jaspers; L. Deldique

    2015-01-01

    Anabolic resistance reflects the inability of skeletal muscle to maintain protein mass by appropriate stimulation of protein synthesis. We hypothesized that endoplasmic reticulum (ER) stress contributes to anabolic resistance in skeletal muscle with aging. Muscles were isolated from adult (8 mo) and

  2. Bacillus pumilus reveals a remarkably high resistance to hydrogen peroxide provoked oxidative stress

    NARCIS (Netherlands)

    Handtke, S.; Schroeter, R.; Jurgen, B.; Methling, K.; Schluter, R.; Albrecht, D.; Hijum, S.A.F.T. van; Bongaerts, J.; Maurer, K.H.; Lalk, M.; Schweder, T.; Hecker, M.; Voigt, B.

    2014-01-01

    Bacillus pumilus is characterized by a higher oxidative stress resistance than other comparable industrially relevant Bacilli such as B. subtilis or B. licheniformis. In this study the response of B. pumilus to oxidative stress was investigated during a treatment with high concentrations of hydrogen

  3. Induction of Drought Stress Resistance by Multi-Functional PGPR Bacillus licheniformis K11 in Pepper

    OpenAIRE

    Lim, Jong-Hui; Kim, Sang-Dal

    2013-01-01

    Drought stress is one of the major yield affecting factor for pepper plant. The effects of PGPRs were analyzed in relation with drought resistance. The PGPRs inoculated pepper plants tolerate the drought stress and survived as compared to non-inoculated pepper plants that died after 15 days of drought stress. Variations in protein and RNA accumulation patterns of inoculated and non-inoculated pepper plants subjected to drought conditions for 10 days were confirmed by two dimensional polyacryl...

  4. Effects of astaxanthin and emodin on the growth, stress resistance and disease resistance of yellow catfish (Pelteobagrus fulvidraco).

    Science.gov (United States)

    Liu, Fei; Shi, Hong-zhuan; Guo, Qiao-sheng; Yu, Ye-bing; Wang, Ai-ming; Lv, Fu; Shen, Wen-biao

    2016-04-01

    Yellow catfish (Pelteobagrus fulvidraco) has become a commercially important fish species in China and eastern Asia. High-density aquaculture has led to congestion and excessive stress and contributed to bacterial infection outbreaks that have caused high mortality. We investigated the effects of dietary supplementation with astaxanthin and emodin alone and in combination on the growth and stress resistance of yellow catfish. After 60 days of feeding, each group of fish (control, astaxanthin, emodin, and astaxanthin plus emodin (combination) groups) was exposed to acute crowding stress for 24 h, and a subsample of fish from the four groups was challenged with the bacterial septicemia pathogen Proteus mirabilis after the end of the crowding stress experiment. Compared with the control, the astaxanthin and emodin groups showed increases in serum total protein (TP), hepatic superoxide dismutase (SOD) activity and hepatic heat shock proteins 70 (HSP70) mRNA levels at 12 and 24 h after the initiation of crowding stress. The combination group exhibited increases in alanine aminotransferase (ALT) activity, aspartate aminotransferase (AST) activity, serum TP, hepatic SOD activity and hepatic HSP70 mRNA levels within 24 h after the initiation of crowding stress. However, decreases relative to the control were observed in the serum cortisol and glucose contents in the three treatment groups at 12 and 24 h after the initiation of crowding stress, in ALT and AST activity in the astaxanthin and emodin group at 24 h after the initiation of crowding stress, and in the serum lysozyme activity, serum alkaline phosphatase (ALP) activity, and hepatic catalase (CAT) and malondialdehyde (MDA) activity in the combination group at 24 h after the initiation of crowding stress. Additionally, the cumulative mortality after P. mirabilis infection was lower in all three treatment groups (57.00%-70.33%) than in the control (77.67%). Dietary supplementation with astaxanthin and emodin decreased

  5. Increased resistance to a generalist herbivore in a salinity-stressed non-halophytic plant.

    Science.gov (United States)

    Renault, Sylvie; Wolfe, Scott; Markham, John; Avila-Sakar, Germán

    2016-01-01

    Plants often grow under the combined stress of several factors. Salinity and herbivory, separately, can severely hinder plant growth and reproduction, but the combined effects of both factors are still not clearly understood. Salinity is known to reduce plant tissue nitrogen content and growth rates. Since herbivores prefer tissues with high N content, and biochemical pathways leading to resistance are commonly elicited by salt-stress, we hypothesized that plants growing in saline conditions would have enhanced resistance against herbivores. The non-halophyte, Brassica juncea, and the generalist herbivore Trichoplusia ni were used to test the prediction that plants subjected to salinity stress would be both more resistant and more tolerant to herbivory than those growing without salt stress. Plants were grown under different NaCl levels, and either exposed to herbivores and followed by removal of half of their leaves, or left intact. Plants were left to grow and reproduce until senescence. Tissue quality was assessed, seeds were counted and biomass of different organs measured. Plants exposed to salinity grew less, had reduced tissue nitrogen, protein and chlorophyll content, although proline levels increased. Specific leaf area, leaf water content, transpiration and root:shoot ratio remained unaffected. Plants growing under saline condition had greater constitutive resistance than unstressed plants. However, induced resistance and tolerance were not affected by salinity. These results support the hypothesis that plants growing under salt-stress are better defended against herbivores, although in B. juncea this may be mostly through resistance, and less through tolerance. PMID:27169610

  6. THE STRESS RESISTANCE OF STUDENTS. THE PARADIGM OF SUBJECT PERSONALITY SELF- ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Sergey I. Dyakov

    2016-01-01

    Full Text Available The aim of the investigation is to consider a problem of stress resistance of students in the context of subject self-organization of the personality. Methods. The following methods of research are used: questioning; psychological and diagnostic tests «Tolerance of Uncertainty» (NTN and «Personal Factors of Decisions» (PFD by T. V. Kornilova; original experimental experiences – «Coding», a technique of a self-assessment (scaling and «A locus control». While data processing the methods of mathematical statistics (SPSS 12 package – the correlation analysis of Pearson and the factorial analysis with rotation use a component by «verimax» method are applied. Results and scientific novelty. Types of subjectivity and strategy of stress resistance are allocated. The nature and a role of the emotional and stressful mechanism having information and semantic properties in its basis are disclosed. Communication of irresponsible mechanisms of mentality with the sphere of consciousness in the context of subjectivity of the personality is shown. Mechanisms of emotional and rational self-control of system of mental self-organization of the person are presented. The statistical and qualitative data opening communications between properties of subjectivity and stress resistance of the personality are empirically obtained. Variation of the relations and also types of subjectivity and stress resistance emphasized based on the results of the presented research. Original (author’s methods of studying of subjectivity and factors of stress resistance are presented. Practical significance. The revealed factors of subject self-organization reveal the stress-producing directions of the environment and the relation of the personality to situations of changes and uncertainty: and also indicate subject properties of resistance to stress which need to be developed to increase the level of health of students, to reduce risk of deviance and delinquency of

  7. Influence of stress on creep deformation properties of 9-12Cr ferritic creep resistant steels

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, K.; Sawada, K.; Kushima, H. [National Institute for Materials Science (Japan)

    2008-07-01

    Creep deformation property of 9-12Cr ferritic creep resistant steels was investigated. With decrease in stress, a magnitude of creep strain at the onset of accelerating creep stage decreased from about 2% in the short-term to less than 1% in the longterm. A time to 1% total strain was observed in the transient creep stage in the short term regime, however, it shifted to the accelerating creep stage in the long-term regime. Life fraction of the times to 1% creep strain and 1% total strain tended to increase with decrease in stress. Difference in stress dependence of the minimum creep rate was observed in the high- and low-stress regimes with a boundary condition of 50% of 0.2% offset yield stress. Stress dependence of the minimum creep rate in the high stress regime was equivalent to a strain rate dependence of the flow stress evaluated by tensile test, and a magnitude of stress exponent, n, in the high stress regime decreased with increase in temperature from 20 at 550 C to 10 at 700 C. On the other hand, n value in the low stress regime was about 5, and creep deformation in the low stress regime was considered to be controlled by dislocation climb. Creep rupture life was accurately predicted by a region splitting method by considering a change in stress dependence of creep deformation. (orig.)

  8. Reduced resistance to oxidative stress during reproduction as a cost of early-life stress

    OpenAIRE

    Zimmer, C; Spencer, K A

    2015-01-01

    This study was funded by a BBSRC David Phillips Research Fellowship to K.A. Spencer. Stress exposure during early-life development can have long-term consequences for a variety of biological functions including oxidative stress. The link between early-life stress and oxidative balance is beginning to be explored and previous studies have focused on this link in adult non-breeding or immature individuals. However, as oxidative stress is considered as the main physiological mechanism underly...

  9. Coupled stress-strain and electrical resistivity measurements on copper based shape memory single crystals

    Directory of Open Access Journals (Sweden)

    Gonzalez Cezar Henrique

    2004-01-01

    Full Text Available Recently, electrical resistivity (ER measurements have been done during some thermomechanical tests in copper based shape memory alloys (SMA's. In this work, single crystals of Cu-based SMA's have been studied at different temperatures to analyse the relationship between stress (s and ER changes as a function of the strain (e. A good consistency between ER change values is observed in different experiments: thermal martensitic transformation, stress induced martensitic transformation and stress induced reorientation of martensite variants. During stress induced martensitic transformation (superelastic behaviour and stress induced reorientation of martensite variants, a linear relationship is obtained between ER and strain as well as the absence of hys teresis. In conclusion, the present results show a direct evidence of martensite electrical resistivity anisotropy.

  10. Differential importance of trehalose in stress resistance in fermenting and nonfermenting Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Van Dijck, P; Colavizza, D; Smet, P; Thevelein, J M

    1995-01-01

    The trehalose content in laboratory and industrial baker's yeast is widely believed to be a major determinant of stress resistance. Fresh and dried baker's yeast is cultured to obtain a trehalose content of more than 10% of the dry weight. Initiation of fermentation, e.g., during dough preparation, is associated with a rapid loss of stress resistance and a rapid mobilization of trehalose. Using specific Saccharomyces cerevisiae mutants affected in trehalose metabolism, we confirm the correlation between trehalose content and stress resistance but only in the absence of fermentation. We demonstrate that both phenomena can be dissociated clearly once the cells initiate fermentation. This was accomplished both for cells with moderate trehalose levels grown under laboratory conditions and for cells with trehalose contents higher than 10% obtained under pilot-scale conditions. Retention of a high trehalose level during fermentation also does not prevent the loss of fermentation capacity during preparation of frozen doughs. Although higher trehalose levels are always correlated with higher stress resistance before the addition of fermentable sugar, our results show that the initiation of fermentation causes the disappearance of any other factor(s) required for the maintenance of stress resistance, even in the presence of a high trehalose content. PMID:7887593

  11. Alterations in neuronal morphology in infralimbic cortex predict resistance to fear extinction following acute stress.

    Science.gov (United States)

    Moench, Kelly M; Maroun, Mouna; Kavushansky, Alexandra; Wellman, Cara

    2016-06-01

    Dysfunction in corticolimbic circuits that mediate the extinction of learned fear responses is thought to underlie the perseveration of fear in stress-related psychopathologies, including post-traumatic stress disorder. Chronic stress produces dendritic hypertrophy in basolateral amygdala (BLA) and dendritic hypotrophy in medial prefrontal cortex, whereas acute stress leads to hypotrophy in both BLA and prelimbic cortex. Additionally, both chronic and acute stress impair extinction retrieval. Here, we examined the effects of a single elevated platform stress on extinction learning and dendritic morphology in infralimbic cortex, a region considered to be critical for extinction. Acute stress produced resistance to extinction, as well as dendritic retraction in infralimbic cortex. Spine density on apical and basilar terminal branches was unaffected by stress. However, animals that underwent conditioning and extinction had decreased spine density on apical terminal branches. Thus, whereas dendritic morphology in infralimbic cortex appears to be particularly sensitive to stress, changes in spines may more sensitively reflect learning. Further, in stressed rats that underwent conditioning and extinction, the level of extinction learning was correlated with spine densities, in that rats with poorer extinction retrieval had more immature spines and fewer thin spines than rats with better extinction retrieval, suggesting that stress may have impaired learning-related spine plasticity. These results may have implications for understanding the role of medial prefrontal cortex in learning deficits associated with stress-related pathologies. PMID:26844245

  12. Aging related ER stress is not responsible for anabolic resistance in mouse skeletal muscle.

    Science.gov (United States)

    Chalil, Sreeda; Pierre, Nicolas; Bakker, Astrid D; Manders, Ralph J; Pletsers, Annelies; Francaux, Marc; Klein-Nulend, Jenneke; Jaspers, Richard T; Deldicque, Louise

    2015-12-25

    Anabolic resistance reflects the inability of skeletal muscle to maintain protein mass by appropriate stimulation of protein synthesis. We hypothesized that endoplasmic reticulum (ER) stress contributes to anabolic resistance in skeletal muscle with aging. Muscles were isolated from adult (8 mo) and old (26 mo) mice and weighed. ER stress markers in each muscle were quantified, and the anabolic response to leucine was assessed by measuring the phosphorylation state of S6K1 in soleus and EDL using an ex vivo muscle model. Aging reduced the muscle-to-body weight ratio in soleus, gastrocnemius, and plantaris, but not in EDL and tibialis anterior. Compared to adult mice, the expression of ER stress markers BiP and IRE1α was higher in EDL, and phospho-eIF2α was higher in soleus and EDL of old mice. S6K1 response to leucine was impaired in soleus, but not in EDL, suggesting that anabolic resistance contributes to soleus weight loss in old mice. Pre-incubation with ER stress inducer tunicamycin before leucine stimulation increased S6K1 phosphorylation beyond the level reached by leucine alone. Since tunicamycin did not impair leucine-induced S6K1 response, and based on the different ER stress marker regulation patterns, ER stress is probably not involved in anabolic resistance in skeletal muscle with aging.

  13. Pneumococcal Gene Complex Involved in Resistance to Extracellular Oxidative Stress

    NARCIS (Netherlands)

    Andisi, Vahid Farshchi; Hinojosa, Cecilia A.; de Jong, Anne; Kuipers, Oscar P.; Orihuela, Carlos J.; Bijlsma, Jetta J. E.; Weiser, J.N.

    2012-01-01

    Streptococcus pneumoniae is a Gram-positive bacterium which is a member of the normal human nasopharyngeal flora but can also cause serious disease such as pneumonia, bacteremia, and meningitis. Throughout its life cycle, S. pneumoniae is exposed to significant oxidative stress derived from endogeno

  14. Microarray analyses reveal novel targets of exercise-induced stress resistance in the dorsal raphe nucleus

    Directory of Open Access Journals (Sweden)

    Alice B. Loughridge

    2013-05-01

    Full Text Available Serotonin (5-HT is implicated in the development of stress-related mood disorders in humans. Physical activity reduces the risk of developing stress-related mood disorders, such as depression and anxiety. In rats, 6 weeks of wheel running protects against stress-induced behaviors thought to resemble symptoms of human anxiety and depression. The mechanisms by which exercise confers protection against stress-induced behaviors, however, remain unknown. One way by which exercise could generate stress resistance is by producing plastic changes in gene expression in the dorsal raphe nucleus (DRN. The DRN has a high concentration of 5-HT neurons and is implicated in stress-related mood disorders. The goal of the current experiment was to identify changes in the expression of genes that could be novel targets of exercise-induced stress resistance in the DRN. Adult, male F344 rats were allowed voluntary access to running wheels for 6 weeks; exposed to inescapable stress or no stress; and sacrificed immediately and 2 hours after stressor termination. Laser capture microdissection selectively sampled the DRN. mRNA expression was measured using the whole genome Affymetrix microarray. Comprehensive data analyses of gene expression included differential gene expression, log fold change (LFC contrast analyses with False Discovery Rate correction, KEGG and Wiki Web Gestalt pathway enrichment analyses, and Weighted Gene Correlational Network Analysis (WGCNA. Our results suggest that physically active rats exposed to stress modulate expression of twice the number of genes, and display a more rapid and strongly coordinated response, than sedentary rats. Bioinformatics analyses revealed several potential targets of stress resistance including genes that are related to immune processes, tryptophan metabolism, and circadian/diurnal rhythms.

  15. Stress-induced enhancement of fear conditioning and sensitization facilitates extinction-resistant and habituation-resistant fear behaviors in a novel animal model of posttraumatic stress disorder.

    Science.gov (United States)

    Corley, Michael J; Caruso, Michael J; Takahashi, Lorey K

    2012-01-18

    Posttraumatic stress disorder (PTSD) is characterized by stress-induced symptoms including exaggerated fear memories, hypervigilance and hyperarousal. However, we are unaware of an animal model that investigates these hallmarks of PTSD especially in relation to fear extinction and habituation. Therefore, to develop a valid animal model of PTSD, we exposed rats to different intensities of footshock stress to determine their effects on either auditory predator odor fear extinction or habituation of fear sensitization. In Experiment 1, rats were exposed to acute footshock stress (no shock control, 0.4 mA, or 0.8 mA) immediately prior to auditory fear conditioning training involving the pairing of auditory clicks with a cloth containing cat odor. When presented to the conditioned auditory clicks in the next 5 days of extinction testing conducted in a runway apparatus with a hide box, rats in the two shock groups engaged in higher levels of freezing and head out vigilance-like behavior from the hide box than the no shock control group. This increase in fear behavior during extinction testing was likely due to auditory activation of the conditioned fear state because Experiment 2 demonstrated that conditioned fear behavior was not broadly increased in the absence of the conditioned auditory stimulus. Experiment 3 was then conducted to determine whether acute exposure to stress induces a habituation resistant sensitized fear state. We found that rats exposed to 0.8 mA footshock stress and subsequently tested for 5 days in the runway hide box apparatus with presentations of nonassociative auditory clicks exhibited high initial levels of freezing, followed by head out behavior and culminating in the occurrence of locomotor hyperactivity. In addition, Experiment 4 indicated that without delivery of nonassociative auditory clicks, 0.8 mA footshock stressed rats did not exhibit robust increases in sensitized freezing and locomotor hyperactivity, albeit head out vigilance

  16. Resistance to Early-Life Stress in Mice: Effects of Genetic Background and Stress Duration

    OpenAIRE

    Savignac, Hélène M.; Dinan, Timothy G.; Cryan, John F.

    2011-01-01

    Early-life stress can induce marked behavioral and physiological impairments in adulthood including cognitive deficits, depression, anxiety, and gastrointestinal dysfunction. Although robust rat models of early-life stress exist there are few established effective paradigms in the mouse. Genetic background and protocol parameters used are two critical variables in such model development. Thus we investigated the impact of two different early-life stress protocols in two commonly used inbred m...

  17.     Developmental acclimation affects clinal variation in stress resistance traits in Drosophila buzzatii

    DEFF Research Database (Denmark)

    Sarup, Pernille Merete; Loeschcke, Volker

    2010-01-01

    -down resistance after development at either constant or fluctuating temperatures in nine Drosophila buzzatii populations collected along an altitudinal gradient in Tenerife, Spain. Flies that developed at fluctuating temperatures had higher stress resistance despite experiencing a slightly lower average...

  18. [Improving industrial microbial stress resistance by metabolic engineering: a review].

    Science.gov (United States)

    Fu, Ruiyan; Li, Yin

    2010-09-01

    Metabolic engineering is a technologic platform for industrial strain improvement and aims not only at modifying microbial metabolic fluxes, but also improving the physiological performance of industrial microbes. Microbes will meet multiple stresses in industrial processes. Consequently, elicited gene responses might result in a decrease in overall cell fitness and the efficiency of biotransformation. Thus, it is crucial to develop robust and productive microbial strains that can be integrated into industrial-scale bioprocesses. In this review, we focus on the progress of these novel methods and strategies for engineering stress-tolerance phenotypes referring to rational metabolic engineering and inverse metabolic engineering in recent years. In addition, we also address problems existing in this area and future research needs of microbial physiological functionality engineering.

  19. Role of polyisoprenoids in tobacco resistance against biotic stresses.

    Science.gov (United States)

    Bajda, Agnieszka; Konopka-Postupolska, Dorota; Krzymowska, Magdalena; Hennig, Jacek; Skorupinska-Tudek, Karolina; Surmacz, Liliana; Wójcik, Jacek; Matysiak, Zdzislaw; Chojnacki, Tadeusz; Skorzynska-Polit, Ewa; Drazkiewicz, Maria; Patrzylas, Pawel; Tomaszewska, Monika; Kania, Magdalena; Swist, Malgorzata; Danikiewicz, Witold; Piotrowska, Wieslawa; Swiezewska, Ewa

    2009-04-01

    Infection with avirulent pathogens, tobacco mosaic virus (TMV) or Pseudomonas syringae pv. tabaci induced accumulation of polyisoprenoid alcohols, solanesol and a family of polyprenols [from polyprenol composed of 14 isoprene units (Pren-14) to -18, with Pren-16 dominating] in the leaves of resistant tobacco plants Nicotiana tabacum cv. Samsun NN. Upon TMV infection, solanesol content was increased seven- and eight-fold in the inoculated and upper leaves, respectively, while polyprenol content was increased 2.5- and 2-fold in the inoculated and upper leaves, respectively, on the seventh day post-infection. Accumulation of polyisoprenoid alcohols was also stimulated by exogenously applied hydrogen peroxide but not by exogenous salicylic acid (SA). On the contrary, neither inoculation of the leaves of susceptible tobacco plants nor wounding of tobacco leaves caused an increase in polyisoprenoid content. Taken together, these results indicate that polyisoprenoid alcohols might be involved in plant resistance against pathogens. A putative role of accumulated polyisoprenoids in plant response to pathogen attack is discussed. Similarly, the content of plastoquinone (PQ) was increased two-fold in TMV-inoculated and upper leaves of resistant plants. Accumulation of PQ was also stimulated by hydrogen peroxide, bacteria (P. syringae) and SA. The role of PQ in antioxidant defense in cellular membranous compartments is discussed in the context of the enzymatic antioxidant machinery activated in tobacco leaves subjected to viral infection. Elevated activity of several antioxidant enzymes (ascorbate peroxidase, guaiacol peroxidase, glutathione reductase and superoxide dismutase, especially the CuZn superoxide dismutase isoform) and high, but transient elevation of catalase was found in inoculated leaves of resistant tobacco plants but not in susceptible plants. PMID:19292825

  20. Coral thermal tolerance: tuning gene expression to resist thermal stress.

    Directory of Open Access Journals (Sweden)

    Anthony J Bellantuono

    Full Text Available The acclimatization capacity of corals is a critical consideration in the persistence of coral reefs under stresses imposed by global climate change. The stress history of corals plays a role in subsequent response to heat stress, but the transcriptomic changes associated with these plastic changes have not been previously explored. In order to identify host transcriptomic changes associated with acquired thermal tolerance in the scleractinian coral Acropora millepora, corals preconditioned to a sub-lethal temperature of 3°C below bleaching threshold temperature were compared to both non-preconditioned corals and untreated controls using a cDNA microarray platform. After eight days of hyperthermal challenge, conditions under which non-preconditioned corals bleached and preconditioned corals (thermal-tolerant maintained Symbiodinium density, a clear differentiation in the transcriptional profiles was revealed among the condition examined. Among these changes, nine differentially expressed genes separated preconditioned corals from non-preconditioned corals, with 42 genes differentially expressed between control and preconditioned treatments, and 70 genes between non-preconditioned corals and controls. Differentially expressed genes included components of an apoptotic signaling cascade, which suggest the inhibition of apoptosis in preconditioned corals. Additionally, lectins and genes involved in response to oxidative stress were also detected. One dominant pattern was the apparent tuning of gene expression observed between preconditioned and non-preconditioned treatments; that is, differences in expression magnitude were more apparent than differences in the identity of genes differentially expressed. Our work revealed a transcriptomic signature underlying the tolerance associated with coral thermal history, and suggests that understanding the molecular mechanisms behind physiological acclimatization would be critical for the modeling of reefs

  1. Focus ion beam-induced mechanical stress switching in an ultra-fast resistive switching device

    Science.gov (United States)

    Yang, Xiang

    2016-06-01

    The Mo/Si3N4:Pt/Pt nanometallic resistive switching devices with ultra-fast write/erase speed (meta-stable state, while LRS (detrapping state) is a stable state. Strong mechanical stress facilitates local bond distortion in dielectric films and thus lowers the energy barrier between HRS and LRS, eventually leading to a barrier-less state transition. A quantitative model based on stress-mediated parallel conduction paths were established to provide a more accurate description of the resistive switching devices.

  2. Plastic responses to four environmental stresses and cross-resistance in a laboratory population of Drosophila melanogaster

    DEFF Research Database (Denmark)

    Bubliy, Oleg A; Kristensen, Torsten Nygård; Kellermann, Vanessa;

    2012-01-01

    such as reduction of metabolic rate and accumulation of energy reserves might be involved. 6. The lack of cross-resistance induced by acclimation ⁄ hardening treatments suggests that in an environment with multiple stresses, evolution of shared protective systems associated with plastic responses may be constrained.......1. Acclimation or hardening to one stress in arthropods can lead to a plastic response, which confers increased resistance to other stresses. Such cross-resistance may indicate shared physiological resistance mechanisms and a possibility of joint evolution for resistance traits. 2. In this study...

  3. Response of Herbicide-Resistant Palmer Amaranth (Amaranthus palmeri Accessions to Drought Stress

    Directory of Open Access Journals (Sweden)

    Aman Chandi

    2013-01-01

    Full Text Available Palmer amaranth is a very problematic weed in several crops in the southern USA due to its competitive ability and resistance to herbicides representing different mechanisms of action. Variation in growth and subsequent interference of North Carolina Palmer amaranth accessions has not been examined. A greenhouse experiment determined response of 15 North Carolina Palmer amaranth accessions to drought stress beginning 15 days after seedling emergence (DAE for a duration of 3, 5, 7, and 9 days. Following exposure to drought, plants were grown under optimal moisture conditions until harvest at 30 DAE. Five accessions each of glyphosate-resistant (GR, acetolactate synthase inhibitor-resistant (ALSR, and acetolactate synthase inhibitor-susceptible and glyphosate-susceptible (ALSS/GS were compared. Variation in response to drought stress, based on height and dry weight reduction relative to nonstressed controls, was noted among accessions. Stress for 3 or more days affected height and dry weight. Height and dry weight of GR and ALSR accession groups were reduced less by drought than the ALSS/GS accession group. Results suggest a possible relationship between herbicide resistance and ability of Palmer amaranth to withstand drought stress and thus a possible competitive advantage for resistant accessions under limited moisture availability.

  4. Benfotiamine attenuates nicotine and uric acid-induced vascular endothelial dysfunction in the rat.

    Science.gov (United States)

    Balakumar, Pitchai; Sharma, Ramica; Singh, Manjeet

    2008-01-01

    The study has been designed to investigate the effect of benfotiamine, a thiamine derivative, in nicotine and uric acid-induced vascular endothelial dysfunction (VED) in rats. Nicotine (2 mg kg(-1)day(-1), i.p., 4 weeks) and uric acid (150 mg kg(-1)day(-1), i.p., 3 weeks) were administered to produce VED in rats. The development of VED was assessed by employing isolated aortic ring preparation and estimating serum and aortic concentration of nitrite/nitrate. Further, the integrity of vascular endothelium was assessed using the scanning electron microscopy (SEM) of thoracic aorta. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances (TBARS) and aortic superoxide anion generation. The administration of nicotine and uric acid produced VED by impairing the integrity of vascular endothelium and subsequently decreasing serum and aortic concentration of nitrite/nitrate and attenuating acetylcholine-induced endothelium dependent relaxation. Further, nicotine and uric acid produced oxidative stress, which was assessed in terms of increase in serum TBARS and aortic superoxide generation. However, treatment with benfotiamine (70 mg kg(-1)day(-1), p.o.) or atorvastatin (30 mg kg(-1)day(-1) p.o., a standard agent) markedly prevented nicotine and uric acid-induced VED and oxidative stress by improving the integrity of vascular endothelium, increasing the concentration of serum and aortic nitrite/nitrate, enhancing the acetylcholine-induced endothelium dependent relaxation and decreasing serum TBARS and aortic superoxide anion generation. Thus, it may be concluded that benfotiamine reduces the oxidative stress and consequently improves the integrity of vascular endothelium and enhances the generation of nitric oxide to prevent nicotine and uric acid-induced experimental VED.

  5. Insulin resistance improves metabolic and contractile efficiency in stressed rat heart

    OpenAIRE

    Harmancey, Romain; Lam, Truong N.; Lubrano, Genna M.; Patrick H. Guthrie; Vela, Deborah; Taegtmeyer, Heinrich

    2012-01-01

    Insulin resistance is a prominent feature in heart failure, while hyperglycemia impairs cardiac contraction. We propose that decreased insulin-mediated glucose uptake by the heart preserves cardiac function in response to metabolic and hemodynamic stress. To test this hypothesis, we fed rats a high-sucrose diet (HSD). Energy substrate metabolism and cardiac work were determined ex vivo in a sequential protocol simulating metabolic and hemodynamic stress. Compared to chow-fed, control rats, HS...

  6. Modulation of auxin content in Arabidopsis confers improved drought stress resistance.

    Science.gov (United States)

    Shi, Haitao; Chen, Li; Ye, Tiantian; Liu, Xiaodong; Ding, Kejian; Chan, Zhulong

    2014-09-01

    Auxin is a well-known plant phytohormone that is involved in multiple plant growth processes and stress responses. In this study, auxin response was significantly modulated under drought stress condition. The iaaM-OX transgenic lines with higher endogenous indole-3-acetic acid (IAA) level and IAA pre-treated wild type (WT) plants exhibited enhanced drought stress resistance, while the yuc1yuc2yuc6 triple mutants with lower endogenous IAA level showed decreased stress resistance in comparison to non-treated WT plants. Additionally, endogenous and exogenous auxin positively modulated the expression levels of multiple abiotic stress-related genes (RAB18, RD22, RD29A, RD29B, DREB2A, and DREB2B), and positively affected reactive oxygen species (ROS) metabolism and underlying antioxidant enzyme activities. Moreover, auxin significantly modulated some carbon metabolites including amino acids, organic acids, sugars, sugar alcohols and aromatic amines. Notably, endogenous and exogenous auxin positively modulated root architecture especially the lateral root number. Taken together, this study demonstrated that auxin might participate in the positive regulation of drought stress resistance, through regulation of root architecture, ABA-responsive genes expression, ROS metabolism, and metabolic homeostasis, at least partially. PMID:24992887

  7. Listeria monocytogenes growth limits and stress resistance mechanisms

    OpenAIRE

    Veen, van der, J.T.

    2008-01-01

    The food-borne pathogen Listeria monocytogenes is a Gram-positive facultative anaerobic rod, which is the causative agent of listeriosis. Due to the severity of the disease and the fact that its incidence is increasing in numerous European countries, L. monocytogenes is of great public health concern. This bacterium shows relatively high resistance to environmental insults compared with many other non-spore-forming food-borne pathogens. It is able to grow at low pH, at high salt concentration...

  8. Targeting the cell stress response of Plasmodium falciparum to overcome artemisinin resistance.

    Science.gov (United States)

    Dogovski, Con; Xie, Stanley C; Burgio, Gaetan; Bridgford, Jess; Mok, Sachel; McCaw, James M; Chotivanich, Kesinee; Kenny, Shannon; Gnädig, Nina; Straimer, Judith; Bozdech, Zbynek; Fidock, David A; Simpson, Julie A; Dondorp, Arjen M; Foote, Simon; Klonis, Nectarios; Tilley, Leann

    2015-04-01

    Successful control of falciparum malaria depends greatly on treatment with artemisinin combination therapies. Thus, reports that resistance to artemisinins (ARTs) has emerged, and that the prevalence of this resistance is increasing, are alarming. ART resistance has recently been linked to mutations in the K13 propeller protein. We undertook a detailed kinetic analysis of the drug responses of K13 wild-type and mutant isolates of Plasmodium falciparum sourced from a region in Cambodia (Pailin). We demonstrate that ART treatment induces growth retardation and an accumulation of ubiquitinated proteins, indicative of a cellular stress response that engages the ubiquitin/proteasome system. We show that resistant parasites exhibit lower levels of ubiquitinated proteins and delayed onset of cell death, indicating an enhanced cell stress response. We found that the stress response can be targeted by inhibiting the proteasome. Accordingly, clinically used proteasome inhibitors strongly synergize ART activity against both sensitive and resistant parasites, including isogenic lines expressing mutant or wild-type K13. Synergy is also observed against Plasmodium berghei in vivo. We developed a detailed model of parasite responses that enables us to infer, for the first time, in vivo parasite clearance profiles from in vitro assessments of ART sensitivity. We provide evidence that the clinical marker of resistance (delayed parasite clearance) is an indirect measure of drug efficacy because of the persistence of unviable parasites with unchanged morphology in the circulation, and we suggest alternative approaches for the direct measurement of viability. Our model predicts that extending current three-day ART treatment courses to four days, or splitting the doses, will efficiently clear resistant parasite infections. This work provides a rationale for improving the detection of ART resistance in the field and for treatment strategies that can be employed in areas with ART

  9. Temperature-stress resistance and tolerance along a latitudinal cline in North American Arabidopsis lyrata.

    Directory of Open Access Journals (Sweden)

    Guillaume Wos

    Full Text Available The study of latitudinal gradients can yield important insights into adaptation to temperature stress. Two strategies are available: resistance by limiting damage, or tolerance by reducing the fitness consequences of damage. Here we studied latitudinal variation in resistance and tolerance to frost and heat and tested the prediction of a trade-off between the two strategies and their costliness. We raised plants of replicate maternal seed families from eight populations of North American Arabidopsis lyrata collected along a latitudinal gradient in climate chambers and exposed them repeatedly to either frost or heat stress, while a set of control plants grew under standard conditions. When control plants reached maximum rosette size, leaf samples were exposed to frost and heat stress, and electrolyte leakage (PEL was measured and treated as an estimate of resistance. Difference in maximum rosette size between stressed and control plants was used as an estimate of tolerance. Northern populations were more frost resistant, and less heat resistant and less heat tolerant, but-unexpectedly-they were also less frost tolerant. Negative genetic correlations between resistance and tolerance to the same and different thermal stress were generally not significant, indicating only weak trade-offs. However, tolerance to frost was consistently accompanied by small size under control conditions, which may explain the non-adaptive latitudinal pattern for frost tolerance. Our results suggest that adaptation to frost and heat is not constrained by trade-offs between them. But the cost of frost tolerance in terms of plant size reduction may be important for the limits of species distributions and climate niches.

  10. Insulin resistance in H pylori infection and its association with oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Mehmet Aslan; Mehmet Horoz; Yasar Nazligul; Cengiz Bolukbas; F Fusun Bolukbas; Sahbettin Selek; Hakim Celik; Ozcan Erel

    2006-01-01

    AIM:To determine the insulin resistance (IR) and oxidative status in H pylori infection and to find out if there is any relationship between these parameters and insulin resistance.METHODS:Fifty-five H pylori positive and 48 H pylori negative patients were enrolled. The homeostasis model assessment (HOMA) was used to assess insulin resistance. Serum total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined in all subjects.RESULTS:The total antioxidant capacity was significantly lower in H pylori positive group than in H pylori negative group (1.36 ± 0.33 and 1.70 ± 0.50,respectively; P < 0.001), while the total oxidant status and oxidative stress index were significantly higher in H pylori positive group than in H pylori negative group (6.79 ± 3.40 and 5.08 ± 0.95, and 5.42 ± 3.40 and 3.10± 0.92, respectively; P < 0.001). Insulin resistance was significantly higher in H pylori positive group than in H pylori negative group (6.92 ± 3.86 and 3.61 ± 1.67, respectively; P < 0.001). Insulin resistance was found to be significantly correlated with total antioxidant capacity (r= -0.251, P < 0.05), total oxidant status (r = 0.365, P <0.05), and oxidative stress index (r = 0.267, P < 0.05).CONCLUSION: Insulin resistance seems to be associated with increased oxidative stress in H pylori infection.Further studies are needed to clarify the mechanisms underlying this association and elucidate the effect of adding antioxidant vitamins to H pylori eradication therapy on insulin resistance during H pylori infection.

  11. Effect of Residual Stress on the Wear Resistance of Thermal Spray Coatings

    Science.gov (United States)

    Luo, W.; Selvadurai, U.; Tillmann, W.

    2016-01-01

    The wear resistance of thermal spray coatings mainly depends on coating properties such as the microstructure, hardness, and porosity, as well as on the residual stress in the coating. The residual stress is induced by a variety of influences e.g., temperature gradients, difference of the thermal expansion coefficient of the coating/substrate materials, and the geometry of the components. To investigate the residual stress, the impulse excitation technique was employed to measure the Young's and shear moduli. The residual stress was determined by the hole-drilling method and x-ray diffraction. Pin-on-Disk and Pin-on-Tube tests were used to investigate the wear behavior. After the wear tests, the wear volume was measured by means of a 3D-profilometer. The results show that the value of the residual stress can be modified by varying the coating thickness and the substrate geometry. The compressive stress in the HVOF-sprayed WC-Co coatings has a significant positive influence on the wear resistance whereas the tensile stress has a negative effect.

  12. Resistance to early-life stress in mice: effects of genetic background and stress duration

    Directory of Open Access Journals (Sweden)

    Helene M. Savignac

    2011-04-01

    Full Text Available Early-life stress can induce marked behavioural and physiological impairments in adulthood including cognitive deficits, depression, anxiety and gastrointestinal dysfunction. Although robust rat models of early-life stress exist there are few established effective paradigms in the mouse. Genetic background and protocol parameters used are two critical variables in such model development.Thus we investigated the impact of two different early-life stress protocols in two commonly used inbred mouse strains. C57BL/6 and innately anxious BALB/c male mice were maternally deprived 3 hrs daily, either from postnatal day 1 to 14 (Protocol 1 or 6 to 10 (Protocol 2. Animals were assessed in adulthood for cognitive performance (spontaneous alternation behaviour test, anxiety (open field, light/dark box and elevated plus maze tests and depression-related behaviours (forced swim test in addition to stress-sensitive physiological changes. Overall, the results showed that early-life stressed mice from both strains displayed good cognitive ability and no elevations in anxiety. However, paradoxical changes occurred in C57BL/6 mice as the longer protocol (protocol 1 decreased anxiety in the light-dark box and increased exploration in the elevated plus maze. In BALB/c mice there were also limited effects of maternal separation with both separation protocols inducing reductions in stress-induced defecation and protocol 1 reducing the colon length. These data suggest that, independent of stress duration, mice from both strains were on the whole resilient to the maladaptive effects of early-life stress. Thus maternal-separation models of brain-gut axis dysfunction should rely on either different stressor protocols or other strains of mice.

  13. Insulin resistance as a physiological defense against metabolic stress

    DEFF Research Database (Denmark)

    Nolan, Christopher J; Ruderman, Neil B; Kahn, Steven E;

    2015-01-01

    Stratifying the management of type 2 diabetes (T2D) has to take into account marked variability in patient phenotype due to heterogeneity in its pathophysiology, different stages of the disease process, and multiple other patient factors including comorbidities. The focus here is on the very...... to the body and should be counteracted at any cost. Instead we propose that IR, particularly in this high-risk subgroup, is a defense mechanism that protects critical tissues of the cardiovascular system from nutrient-induced injury. Overriding IR in an effort to lower plasma glucose levels, particularly...... with intensive insulin therapy, could therefore be harmful. Treatments that nutrient off-load to lower glucose are more likely to be beneficial. The concepts of "IR as an adaptive defense mechanism" and "insulin-induced metabolic stress" may provide explanation for some of the unexpected outcomes of recent major...

  14. Priming as a mechanism behind induced resistance against pathogens, insects and abiotic stress

    NARCIS (Netherlands)

    Ton, J.; Ent, S. van der; Hulten, M.H.A. van; Pozo, M.; Oosten, V. van; Loon, L.C. van; Mauch-Mani, B.; Turlings, T.C.J.; Pieterse, C.M.J.

    2009-01-01

    Upon treatment with a resistance-inducing agent, plants acquire an enhanced defensive capacity that results in a faster and/or stronger defence reaction at the moment the plant is exposed to biotic or abiotic stress. This phenomenon is commonly known as priming and has been associated with different

  15. Effect of respiration and manganese on oxidative stress resistance of Lactobacillus plantarum WCFS1

    NARCIS (Netherlands)

    Watanabe, M.; Veen, van der S.; Nakajima, H.; Abee, T.

    2012-01-01

    Lactobacillus plantarum is a facultatively anaerobic bacterium that can perform respiration under aerobic conditions in the presence of haem, with vitamin K2 acting as a source of menaquinone. We investigated growth performance and oxidative stress resistance of Lb. plantarum WCFS1 cultures grown in

  16. Impact of Pathogen Population Heterogeneity and Stress-Resistant Variants on Food Safety

    NARCIS (Netherlands)

    Abee, T.; Koomen, J.; Metselaar, K.I.; Zwietering, M.H.; Besten, Den H.M.W.

    2016-01-01

    This review elucidates the state-of-the-art knowledge about pathogen population heterogeneity and describes the genotypic and phenotypic analyses of persister subpopulations and stress-resistant variants. The molecular mechanisms underlying the generation of persister phenotypes and genetic varia

  17. Development of abiotic-stress resistant warm season trufgrasses by proton-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. W.; Kim, J. Y.; Jeong, S. H. [Korea Univ., Seoul (Korea, Republic of)

    2007-04-15

    The direct use of mutation is a valuable approach to generate genetic variation in crop species by altering agronomically useful major traits. The proton beam, as a mutagen, was applied to improve resistance traits of Zoysia grass under various abiotic stresses. Proton beam was irradiated to mature dry seeds of Zenith (Zoysia grass), which is well-adapted to Korean climate, using a proton- accelerator with seven different doses (50, 100, 150, 200, 250, 300, 400 Gy). Individual seedling of M1 plant was transplanted from the seed bed and allowed to reach appropriate plant mass. Clones that showed superior growth were chosen and transplanted to pots for further clone propagation and field evaluation. Growth characteristics of turfgrass, such as plant height, leaf length, leaf width, number of tiller were evaluated ninety days after sowing. Although large variation within each dose, noticeable differences were found among different irradiated doses. Most of the mutant clones derived from the irradiation treatment showed more vigorous growth than the control plants. RAPD (Random Amplified Polymorphic DNA) and AFLP (Amplified Fragment Length Polymorphism) methods were conducted to analyze genomic variations associated with proton beam irradiation. In order to establish selection criteria for selection of salt-stress resistance plants, an in vitro method that is able to select salt-stress resistant mutants in liquid media without ambient disturbances. Total 647 predominance clones that were considered as abiotic stress resistant mutants were transplanted to the field for further evaluation.

  18. Biochemical basis of the high resistance to oxidative stress in Dictyostelium discoideum

    Indian Academy of Sciences (India)

    Bandhana Katoch; Rasheedunnisa Begum

    2003-09-01

    Aerobic organisms experience oxidative stress due to generation of reactive oxygen species during normal aerobic metabolism. In addition, several chemicals also generate reactive oxygen species which induce oxidative stress. Thus oxidative stress constitutes a major threat to organisms living in aerobic environments. Programmed cell death or apoptosis is a physiological mechanism of cell death, that probably evolved with multicellularity, and is indispensable for normal growth and development. Dictyostelium discoideum, an eukaryotic developmental model, shows both unicellular and multicellular forms in its life cycle and exhibits apparent caspase-independent programmed cell death, and also shows high resistance to oxidative stress. An attempt has been made to investigate the biochemical basis for high resistance of D. discoideum cell death induced by different oxidants. Dose-dependent induction of cell death by exogenous addition of hydrogen peroxide (H2O2), in situ generation of H2O2 by hydroxylamine, and nitric oxide (NO) generation by sodium nitroprusside treatment in D. discoideum were studied. The AD50 doses (concentration of the oxidants cusing 50% of the cells to die) after 24 h of treatment were found to be 0.45 mM, 4 mM and 1 mM, respectively. Studies on enzymatic antioxidant status of D. discoideum when subjected to oxidative stress, NO and nutrient stress reveal that superoxide dismutase and catalase were unchanged; a significant induction of glutathione peroxidase was observed. Interestingly, oxidative stress-induced lipid membrane peroxidative damage could not be detected. The results shed light on the biochemical basis for the observed high resistance to oxidative stress in D. discoideum.

  19. Stress corrosion cracking resistance of aluminum alloy 7000 series after two-step aging

    Directory of Open Access Journals (Sweden)

    Jegdić Bore V.

    2015-01-01

    Full Text Available The effect of one step-and a new (short two-step aging on the resistance to stress corrosion cracking of an aluminum alloy 7000 series was investigated, using slow strain rate test and fracture mechanics method. Aging level in the tested alloy was evaluated by means of scanning electron microscopy and measurements of electrical resistivity. It was shown that the alloy after the new two-step aging is significantly more resistant to stress corrosion cracking. Values of tensile properties and fracture toughness are similar for both thermal states. Processes that take place at the crack tip have been considered. The effect of the testing solution temperature on the crack growth rate on the plateau was determined. Two values of the apparent activation energy were obtained. These values correspond to different processes that control crack growth rate on the plateau at higher and lower temperatures. [Projekat Ministarstva nauke Republike Srbije, br. TR 34028 i br. TR 34016

  20. Plasticity in behavioural responses and resistance to temperature stress in Musca domestica

    DEFF Research Database (Denmark)

    Kjaersgaard, Anders; Blackenhorn, Wolf U.; Pertoldi, Cino;

    2015-01-01

    Organisms can respond to and cope with stressful environments in a number of ways including behavioural, morphological and physiological adjustments. To understand the role of behavioural traits in thermal adaptations we compared heat resistance, locomotor (walking and flying) activity, flight...... at the benign temperature, whereas the Spanish flies were able to stay active for longer at the stressful temperature. Population differences in behavioural traits and heat resistance were obtained using flies held for several generations in a laboratory common garden setting; therefore we suggest that exposure......, at the stressful high temperature Spanish flies flew the furthest and Danish flies the shortest distance. Neither body size nor wing loading affected flight performance, although flies with narrower wings tended to fly further (wing shape effect). Swiss flies were most active in terms of locomotor activity...

  1. Biotic stress resistance in agriculture through antimicrobial peptides.

    Science.gov (United States)

    Sarika; Iquebal, M A; Rai, Anil

    2012-08-01

    Antimicrobial peptides (AMPs) are the hosts' defense molecules against microbial pathogens and gaining extensive research attention worldwide. These have been reported to play vital role of host innate immunity in response to microbial challenges. AMPs can be used as a natural antibiotic as an alternative of their chemical counterpart for protection of plants/animals against diseases. There are a number of sources of AMPs including prokaryotic and eukaryotic organisms and are present, both in vertebrates and invertebrates. AMPs can be classified as cationic or anionic, based on net charges. Large number of databases and tools are available in the public domain which can be used for development of new genetically modified disease resistant varieties/breeds for agricultural production. The results of the biotechnological research as well as genetic engineering related to AMPs have shown high potential for reduction of economic losses of agricultural produce due to pathogens. In this article, an attempt has been made to introduce the role of AMPs in relation to plants and animals. Their functional and structural characteristics have been described in terms of its role in agriculture. Different sources of AMPs and importance of these sources has been reviewed in terms of its availability. This article also reviews the bioinformatics resources including different database tools and algorithms available in public domain. References of promising biotechnology research in relation to AMPs, prospects of AMPs for further development of genetically modified varieties/breeds are highlighted. AMPs are valuable resource for students, researchers, educators and medical and industrial personnel.

  2. Endogenous cytokinin overproduction modulates ROS homeostasis and decreases salt stress resistance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yanping eWang

    2015-11-01

    Full Text Available 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 CAT and 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.

  3. Stress concentrator effect on corrosion resistance of welded joints of zirconium - 2.5% niobium alloys

    International Nuclear Information System (INIS)

    Considered is the effect of notches and poor penetrations of 10 and 20% pipeline wall thickness made of Zr - 2.5% Nb alloy on corrosion resistance. Stress concentrator effects have been estimated on the basis of results of cyclic tests in 3% NaCl and pressure tests in water-vapor medium at 300 deg C and 85 atm during 1200 h. Estimated are critical strains and corresponding stresses for basic and a weldmetals. Stress concentrators are shown to low the level of critical stresses of corrosion-mechanical fracture initiation. In water-vapor mixture there found is a corrosion in some zones of welded joint heated in a process of welding over 600 deg C. For such zones registered is the effect of structural-chemical changes, caused by welding

  4. Methuselah-like genes affect development, stress resistance, lifespan and reproduction in Tribolium castaneum.

    Science.gov (United States)

    Li, Chengjun; Zhang, Yi; Yun, Xiaopei; Wang, Yanyun; Sang, Ming; Liu, Xing; Hu, Xingxing; Li, Bin

    2014-10-01

    Methuselah (Mth) is associated with lifespan, stress resistance and reproduction in Drosophila melanogaster, but Mth is not present in nondrosophiline insects. A number of methuselah-likes (mthls) have been identified in nondrosophiline insects, but it is unknown whether the functions of mth are shared by mthls or are divergent from them. Five mthls have been identified in Tribolium castaneum. Although they have different developmental expression patterns, they all enhance resistance to starvation. Only mthl1 and mthl2 enhance resistance to high temperature, whereas mthl4 and mthl5 negatively regulate oxidative stress in T. castaneum. Unlike in the fly with mth mutation, knockdown of mthls, except mthl3, shortens the lifespan of T. castaneum. Moreover, mthl1 and mthl2 are critical for Tribolium development. mthl1 plays important roles in larval and pupal development and adult eclosion, while mthl2 is required for eclosion. Moreover, mthl1 and mthl2 silencing reduces the fertility of T. castaneum, and mthl1 and mthl4 are also essential for embryo development. In conclusion, mthls have a significant effect on insect development, lifespan, stress resistance and reproduction. These results provide experimental evidence for functional divergence among mthls/mth and clues for the signal transduction of Mthls.

  5. Inclusion of copepod Acartia tonsa nauplii in the feeding of Centropomus undecimalis larvae increases stress resistance

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo-Costa

    2015-09-01

    Full Text Available This research represents the first result of studies of the common snook Centropomus undecimalis larvae from broodstock matured in captivity in Brazil. The aim of this study was to evaluate if the inclusion of Acartia tonsa nauplii improves stress resistance of common snook larvae. The larvae were fed with: rotifers Brachionus plicatilis (10 to 15 mL-1; A. tonsa nauplii (0.25 to 0.5 mL-1 and rotifers (5 to 7.5 mL-1, and A. tonsa nauplii (0.12 to 0.25 mL-1. The average percentage of survival of the treatments was 11.9%. At 20 days of age, larvae were subjected to thermal stress. Subsequently, the stress resistance was evaluated. Common snook larvae fed B. plicatilis+A. tonsa reached a higher weight and length (7.5 ± 0.00 mg and 9.1 ± 0.23 mm, respectively and resisted more heat stress (87.4% than larvae fed other foods, indicating that the feed mixture is satisfactory as a starter diet for larvae of common snook. However, more research is needed to confirm these results.

  6. Association of Oxidative Stress and Obesity with Insulin Resistance in Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Das, P; Biswas, S; Mukherjee, S; Bandyopadhyay, S K

    2016-01-01

    Oxidative stress occurs due to delicate imbalance between pro-oxidant and anti oxidant forces in our system. It has been found to be associated with many morbidities but its association with obesity and insulin resistance is still controversial. Here in our study we examined 167 patients of recent onset type 2 diabetes mellitus and 60 age sex matched non-diabetic control. Body Mass Index (BMI), abdominal circumference, fasting blood glucose, serum insulin and plasma Malondealdehyde (MDA, marker for oxidative stress) were measured in them. On the basis of BMI, subjects were divided into obese (BMI≥25) and non obese (BMIdiabetes than their non diabetic controls. The said parameters also showed significant difference in obese and non-obese sub groups. Insulin resistance score showed positive correlation with BMI, abdominal circumference, and plasma MDA, strength of association being highest with abdominal circumference. Plasma MDA was found to have positive correlation with physical parameters. Study concludes that, obesity mainly central type may predispose to insulin resistance and oxidative stress may be a crucial factor in its pathogenesis. Thus, oxidative stress may be the connecting link between obesity and type 2 diabetes mellitus, two on going global epidemics.

  7. Effect of myricetin, pyrogallol, and phloroglucinol on yeast resistance to oxidative stress.

    Science.gov (United States)

    Mendes, Vanda; Vilaça, Rita; de Freitas, Victor; Ferreira, Pedro Moradas; Mateus, Nuno; Costa, Vítor

    2015-01-01

    The health beneficial effects of dietary polyphenols have been attributed to their intrinsic antioxidant activity, which depends on the structure of the compound and number of hydroxyl groups. In this study, the protective effects of pyrogallol, phloroglucinol, and myricetin on the yeast Saccharomyces cerevisiae were investigated. Pyrogallol and myricetin, which have a pyrogallol structure in the B ring, increased H2O2 resistance associated with a reduction in intracellular oxidation and protein carbonylation, whereas phloroglucinol did not exert protective effects. The acquisition of oxidative stress resistance in cells pretreated with pyrogallol and myricetin was not associated with an induction of endogenous antioxidant defences as assessed by the analysis of superoxide dismutase and catalase activities. However, myricetin, which provided greater stress resistance, prevented H2O2-induced glutathione oxidation. Moreover, myricetin increased the chronological lifespan of yeast lacking the mitochondrial superoxide dismutase (Sod2p), which exhibited a premature aging phenotype and oxidative stress sensitivity. These findings show that the presence of hydroxyl groups in the ortho position of the B ring in pyrogallol and myricetin contributes to the antioxidant protection afforded by these compounds. In addition, myricetin may alleviate aging-induced oxidative stress, particularly when redox homeostasis is compromised due to downregulation of endogenous defences present in mitochondria. PMID:26000072

  8. Effect of Myricetin, Pyrogallol, and Phloroglucinol on Yeast Resistance to Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Vanda Mendes

    2015-01-01

    Full Text Available The health beneficial effects of dietary polyphenols have been attributed to their intrinsic antioxidant activity, which depends on the structure of the compound and number of hydroxyl groups. In this study, the protective effects of pyrogallol, phloroglucinol, and myricetin on the yeast Saccharomyces cerevisiae were investigated. Pyrogallol and myricetin, which have a pyrogallol structure in the B ring, increased H2O2 resistance associated with a reduction in intracellular oxidation and protein carbonylation, whereas phloroglucinol did not exert protective effects. The acquisition of oxidative stress resistance in cells pretreated with pyrogallol and myricetin was not associated with an induction of endogenous antioxidant defences as assessed by the analysis of superoxide dismutase and catalase activities. However, myricetin, which provided greater stress resistance, prevented H2O2-induced glutathione oxidation. Moreover, myricetin increased the chronological lifespan of yeast lacking the mitochondrial superoxide dismutase (Sod2p, which exhibited a premature aging phenotype and oxidative stress sensitivity. These findings show that the presence of hydroxyl groups in the ortho position of the B ring in pyrogallol and myricetin contributes to the antioxidant protection afforded by these compounds. In addition, myricetin may alleviate aging-induced oxidative stress, particularly when redox homeostasis is compromised due to downregulation of endogenous defences present in mitochondria.

  9. The effect of acute mental stress on limb vasodilation is unrelated to total peripheral resistance.

    Science.gov (United States)

    Paine, Nicola J; Ring, Christopher; Bosch, Jos A; McIntyre, David; Veldhuijzen van Zanten, Jet J C S

    2013-07-01

    Mental stress can trigger myocardial infarction, with poor vascular responses to stress implicated as a pathway. Vascular stress reactivity can be assessed by different methods, such as total peripheral resistance (TPR) and forearm blood flow (FBF). Little is known about how these vascular assessments are linked. This was examined in two separate studies. Healthy men (Study 1: N = 29, Study 2: N = 23) completed rest and mental arithmetic (Study 1: 8 min, Study 2: 16 min). In both studies, heart rate, mean arterial pressure, and FBF increased in response to stress. In Study 1, no changes in TPR were seen, but Study 2 found stress-induced increases in TPR. FBF was not linked to TPR at any time (all ps > .05). It appears that limb vasculature and TPR responses to stress do not give the same information about impairments of the vasculature. These findings are relevant to the interpretation of prior research findings and the design of future studies on stress and vascular responses.

  10. Ultrasonic Impact Treatment to Improve Stress Corrosion Cracking Resistance of Welded Joints of Aluminum Alloy

    Science.gov (United States)

    Yu, J.; Gou, G.; Zhang, L.; Zhang, W.; Chen, H.; Yang, Y. P.

    2016-07-01

    Stress corrosion cracking is one of the major issues for welded joints of 6005A-T6 aluminum alloy in high-speed trains. High residual stress in the welded joints under corrosion results in stress corrosion cracking. Ultrasonic impact treatment was used to control the residual stress of the welded joints of 6005A-T6 aluminum alloy. Experimental tests show that ultrasonic impact treatment can induce compressive longitudinal and transverse residual stress in the welded joint, harden the surface, and increase the tensile strength of welded joints. Salt-fog corrosion tests were conducted for both an as-welded sample and an ultrasonic impact-treated sample. The surface of the treated sample had far fewer corrosion pits than that of the untreated sample. The treated sample has higher strength and lower tensile residual stress than the untreated sample during corrosion. Therefore, ultrasonic impact treatment is an effective technique to improve the stress corrosion cracking resistance of the welded joints of 6005A-T6 aluminum alloy.

  11. Transcriptome Profiling Revealed Stress-Induced and Disease Resistance Genes Up-Regulated in PRSV Resistant Transgenic Papaya.

    Science.gov (United States)

    Fang, Jingping; Lin, Aiting; Qiu, Weijing; Cai, Hanyang; Umar, Muhammad; Chen, Rukai; Ming, Ray

    2016-01-01

    Papaya is a productive and nutritious tropical fruit. Papaya Ringspot Virus (PRSV) is the most devastating pathogen threatening papaya production worldwide. Development of transgenic resistant varieties is the most effective strategy to control this disease. However, little is known about the genome-wide functional changes induced by particle bombardment transformation. We conducted transcriptome sequencing of PRSV resistant transgenic papaya SunUp and its PRSV susceptible progenitor Sunset to compare the transcriptional changes in young healthy leaves prior to infection with PRSV. In total, 20,700 transcripts were identified, and 842 differentially expressed genes (DEGs) randomly distributed among papaya chromosomes. Gene ontology (GO) category analysis revealed that microtubule-related categories were highly enriched among these DEGs. Numerous DEGs related to various transcription factors, transporters and hormone biosynthesis showed clear differences between the two cultivars, and most were up-regulated in transgenic papaya. Many known and novel stress-induced and disease-resistance genes were most highly expressed in SunUp, including MYB, WRKY, ERF, NAC, nitrate and zinc transporters, and genes involved in the abscisic acid, salicylic acid, and ethylene signaling pathways. We also identified 67,686 alternative splicing (AS) events in Sunset and 68,455 AS events in SunUp, mapping to 10,994 and 10,995 papaya annotated genes, respectively. GO enrichment for the genes displaying AS events exclusively in Sunset was significantly different from those in SunUp. Transcriptomes in Sunset and transgenic SunUp are very similar with noteworthy differences, which increased PRSV-resistance in transgenic papaya. No detrimental pathways and allergenic or toxic proteins were induced on a genome-wide scale in transgenic SunUp. Our results provide a foundation for unraveling the mechanism of PRSV resistance in transgenic papaya. PMID:27379138

  12. The Cytochrome bd Oxidase of Porphyromonas gingivalis Contributes to Oxidative Stress Resistance and Dioxygen Tolerance.

    Directory of Open Access Journals (Sweden)

    Julia Leclerc

    Full Text Available Porphyromonas gingivalis is an etiologic agent of periodontal disease in humans. The disease is associated with the formation of a mixed oral biofilm which is exposed to oxygen and environmental stress, such as oxidative stress. To investigate possible roles for cytochrome bd oxidase in the growth and persistence of this anaerobic bacterium inside the oral biofilm, mutant strains deficient in cytochrome bd oxidase activity were characterized. This study demonstrated that the cytochrome bd oxidase of Porphyromonas gingivalis, encoded by cydAB, was able to catalyse O2 consumption and was involved in peroxide and superoxide resistance, and dioxygen tolerance.

  13. Polyunsaturated Branched-Chain Fatty Acid Geranylgeranoic Acid Induces Unfolded Protein Response in Human Hepatoma Cells.

    Directory of Open Access Journals (Sweden)

    Chieko Iwao

    Full Text Available The acyclic diterpenoid acid geranylgeranoic acid (GGA has been reported to induce autophagic cell death in several human hepatoma-derived cell lines; however, the molecular mechanism for this remains unknown. In the present study, several diterpenoids were examined for ability to induce XBP1 splicing and/or lipotoxicity for human hepatoma cell lines. Here we show that three groups of diterpenoids emerged: 1 GGA, 2,3-dihydro GGA and 9-cis retinoic acid induce cell death and XBP1 splicing; 2 all-trans retinoic acid induces XBP1 splicing but little cell death; and 3 phytanic acid, phytenic acid and geranylgeraniol induce neither cell death nor XBP1 splicing. GGA-induced ER stress/ unfolded protein response (UPR and its lipotoxicity were both blocked by co-treatment with oleic acid. The blocking activity of oleic acid for GGA-induced XBP1 splicing was not attenuated by methylation of oleic acid. These findings strongly suggest that GGA at micromolar concentrations induces the so-called lipid-induced ER stress response/UPR, which is oleate-suppressive, and shows its lipotoxicity in human hepatoma cells.

  14. Angiotensin II receptor blocker ameliorates stress-induced adipose tissue inflammation and insulin resistance.

    Directory of Open Access Journals (Sweden)

    Motoharu Hayashi

    Full Text Available A strong causal link exists between psychological stress and insulin resistance as well with hypertension. Meanwhile, stress-related responses play critical roles in glucose metabolism in hypertensive patients. As clinical trials suggest that angiotensin-receptor blocker delays the onset of diabetes in hypertensive patients, we investigated the effects of irbesartan on stress-induced adipose tissue inflammation and insulin resistance. C57BL/6J mice were subjected to 2-week intermittent restraint stress and orally treated with vehicle, 3 and 10 mg/kg/day irbesartan. The plasma concentrations of lipid and proinflammatory cytokines [Monocyte Chemoattractant Protein-1 (MCP-1, tumor necrosis factor-α, and interleukin-6] were assessed with enzyme-linked immunosorbent assay. Monocyte/macrophage accumulation in inguinal white adipose tissue (WAT was observed with CD11b-positive cell counts and mRNA expressions of CD68 and F4/80 using immunohistochemistry and RT-PCR methods respectively. The mRNA levels of angiotensinogen, proinflammatory cytokines shown above, and adiponectin in WAT were also assessed with RT-PCR method. Glucose metabolism was assessed by glucose tolerance tests (GTTs and insulin tolerance tests, and mRNA expression of insulin receptor substrate-1 (IRS-1 and glucose transporter 4 (GLUT4 in WAT. Restraint stress increased monocyte accumulation, plasma free fatty acids, expression of angiotensinogen and proinflammatory cytokines including MCP-1, and reduced adiponectin. Irbesartan reduced stress-induced monocyte accumulation in WAT in a dose dependent manner. Irbesartan treatment also suppressed induction of adipose angiotensinogen and proinflammatory cytokines in WAT and blood, and reversed changes in adiponectin expression. Notably, irbesartan suppressed stress-induced reduction in adipose tissue weight and free fatty acid release, and improved insulin tolerance with restoration of IRS-1 and GLUT4 mRNA expressions in WAT. The results

  15. Ozone phytotoxicity in relation to stress ethylene evolution and stomatal resistance in cowpea (Vigna unguiculata) cultivars

    Energy Technology Data Exchange (ETDEWEB)

    Adepipe, N.O.; Tingey, D.T.

    1979-01-01

    In greenhouse experiments, the ozone sensitivities of three cowpea cultivars differing in growth habits and some physiological traits were determined and related to stress ethylene production and leaf diffusive resistance. The cultivars were more sensitive at the 3-leaf than at the 2-leaf stages of growth. There was no consistent leaf injury at less than 0.50 ..mu..l/l of ozone for 2 hr. At an ozone concentration of 1.0 ..mu..l/l for 2 hr. the cultivar Adzuki exhibited marked leaf injury, amounting to over 80% symptom coverage of the leaf surface while New Era and Ife Brown sustained leaf injury maxima of 58 and 35% respectively. Stress ethylene production did not differ among the cultivars. While ozone increased stomatal diffusive resistance in all cultivars, there were not significant differences among the cultivars.

  16. Thermal stress resistance and aging effects of Panax notoginseng polysaccharides on Caenorhabditis elegans.

    Science.gov (United States)

    Feng, Shiling; Cheng, Haoran; Xu, Zhou; Shen, Shian; Yuan, Ming; Liu, Jing; Ding, Chunbang

    2015-11-01

    Panax notoginseng attract public attention due to their potential biomedical properties and corresponding health benefits. The present study investigated the anti-aging and thermal stress resistance effects of polysaccharides from P. notoginseng on Caenorhabditis elegans. Results showed polysaccharides had little scavenging ability of reactive oxygen species (ROS) in vitro, but significantly extended lifespan of C. elegans, especially the main root polysaccharide (MRP) which prolongs the mean lifespan of wild type worms by 21%. Further study demonstrated that the heat stress resistance effect of polysaccharides on C. elegans might be attributed to the elevation of antioxidant enzyme activities (both superoxide dismutase (SOD) and catalase (CAT)) and the reduction lipid peroxidation of malondialdehyde (MDA) level. Taken together, the results provided a scientific basis for the further exploitation of the mechanism of longer lifespan controlled by P. notoginseng polysaccharides on C. elegans. The P. notoginseng polysaccharides might be considered as a potential source to delay aging.

  17. Multiple roles of putrescine and spermidine in stress resistance and virulence of Salmonella enterica serovar Typhimurium

    DEFF Research Database (Denmark)

    Espinel, Irene cartas; Guerra, Priscila Regina; Jelsbak, Lotte

    2016-01-01

    infections of mice. Using a S. Typhimurium mutant defective for putrescine and spermidine biosynthesis, we show that polyamines are essential for coping with reactive nitrogen species, possibly linking polyamines to increased intracellular stress resistance. However, using a mouse model defective for nitric....... Typhimurium virulence is the ability to survive and replicate inside macrophages and resisting the antimicrobial attacks in the form of oxidative and nitrosative stress elicited from these cells. In the present study, we have investigated the role of polyamines in intracellular survival and systemic...... retained ability to produce and import putrescine. Interestingly, in this mutant we observe a strong attenuation of virulence during infection of mice proficient and deficient for nitric oxide production suggesting that spermidine, specifically, is essential for virulence of S. Typhimurium....

  18. Heat treatment of NiCrFe alloy 600 to optimize resistance to intergranular stress corrosion

    Science.gov (United States)

    Steeves, A.F.; Bibb, A.E.

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprises heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cooling the alloy body, and heating the cooled body to a temperature between 1100 to 1500/sup 0/F for about 1 to 30 hours.

  19. The Fungal Pathogen Aspergillus fumigatus Regulates Growth, Metabolism, and Stress Resistance in Response to Light

    OpenAIRE

    Fuller, Kevin K.; Ringelberg, Carol S.; Loros, Jennifer J.; Dunlap, Jay C

    2013-01-01

    ABSTRACT Light is a pervasive environmental factor that regulates development, stress resistance, and even virulence in numerous fungal species. Though much research has focused on signaling pathways in Aspergillus fumigatus, an understanding of how this pathogen responds to light is lacking. In this report, we demonstrate that the fungus does indeed respond to both blue and red portions of the visible spectrum. Included in the A. fumigatus light response is a reduction in conidial germinatio...

  20. FUNCTION OF HYDRAULIC AND CHEMICAL WATER STRESS SIGNALIZATION IN EVALUATION OF DROUGHT RESISTANCE OF JUVENILE PLANTS

    OpenAIRE

    OLŠOVSKÁ, K.; BRESTIČ, M.

    2002-01-01

    In laboratory hydroponic experiments with spring barley genotypes the juvenile plants with 5 leaves were tested for their physiological responses to osmotic stress evoked by blocking the water uptake in roots by polyethylenglycol (PEG-6000) and to exogenous abscisic acid (ABA) applied in the nutrient solution which inhibits the stomata opening. Results from the measurements of leaf diffusion resistance, relative water content, transpiration and leaf elongation rates show dominant role of chem...

  1. 2-deoxy-D-glucose-induced metabolic stress enhances resistance to Listeria monocytogenes infection in mice

    Science.gov (United States)

    Miller, E. S.; Bates, R. A.; Koebel, D. A.; Fuchs, B. B.; Sonnenfeld, G.

    1998-01-01

    Exposure to different forms of psychological and physiological stress can elicit a host stress response, which alters normal parameters of neuroendocrine homeostasis. The present study evaluated the influence of the metabolic stressor 2-deoxy-D-glucose (2-DG; a glucose analog, which when administered to rodents, induces acute periods of metabolic stress) on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were injected with 2-DG (500 mg/kg b. wt.) once every 48 h prior to, concurrent with, or after the onset of a sublethal dose of virulent L. monocytogenes. Kinetics of bacterial growth in mice were not altered if 2-DG was applied concurrently or after the start of the infection. In contrast, mice exposed to 2-DG prior to infection demonstrated an enhanced resistance to the listeria challenge. The enhanced bacterial clearance in vivo could not be explained by 2-DG exerting a toxic effect on the listeria, based on the results of two experiments. First, 2-DG did not inhibit listeria replication in trypticase soy broth. Second, replication of L. monocytogenes was not inhibited in bone marrow-derived macrophage cultures exposed to 2-DG. Production of neopterin and lysozyme, indicators of macrophage activation, were enhanced following exposure to 2-DG, which correlated with the increased resistance to L. monocytogenes. These results support the contention that the host response to 2-DG-induced metabolic stress can influence the capacity of the immune system to resist infection by certain classes of microbial pathogens.

  2. ENHANCEMENT OF CHLORIDE RESISTANCE OF PRE-STRESSED CONCRETE SHEET PILE BY BLAST FURNACE SLAG

    OpenAIRE

    Irmawaty, Rita

    2012-01-01

    Chloride-induced corrosion is one of the main mechanisms of deterioration affecting the long-term performance of concrete structures. In Japan, a large majority of structures are built either near the costal or indirect contact with seawater. The durability of reinforced or pre-stressed concrete structure depends on the resistance of concrete to chloride penetration. Naturally concrete provides physical and chemical protection to the reinforcing steel from chloride penetrating. The chloride ...

  3. Decreased skin-mediated detoxification contributes to oxidative stress and insulin resistance.

    Science.gov (United States)

    Liu, Xing-Xing; Sun, Chang-Bin; Yang, Ting-Tong; Li, Da; Li, Chun-Yan; Tian, Yan-Jie; Guo, Ming; Cao, Yu; Zhou, Shi-Sheng

    2012-01-01

    The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Rats received an intraperitoneal glucose injection (2 g/kg) with (sham-nicotinamide and burn-nicotinamide groups) or without (sham-operated and burn groups) coadministration of nicotinamide (100 mg/kg). The results showed that the mRNA of all detoxification-related enzymes tested was detected in sham-operated skin but not in burned skin. The clearance of nicotinamide and N(1)-methylnicotinamide in burned rats was significantly decreased compared with that in sham-operated rats. After glucose loading, burn group showed significantly higher plasma insulin levels with a lower muscle glycogen level than that of sham-operated and sham-nicotinamide groups, although there were no significant differences in blood glucose levels over time between groups. More profound changes in plasma H(2)O(2) and insulin levels were observed in burn-nicotinamide group. It may be concluded that decreased skin detoxification may increase the risk for oxidative stress and insulin resistance.

  4. Decreased Skin-Mediated Detoxification Contributes to Oxidative Stress and Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Xing-Xing Liu

    2012-01-01

    Full Text Available The skin, the body's largest organ, plays an important role in the biotransformation/detoxification and elimination of xenobiotics and endogenous toxic substances, but its role in oxidative stress and insulin resistance is unclear. We investigated the relationship between skin detoxification and oxidative stress/insulin resistance by examining burn-induced changes in nicotinamide degradation. Rats were divided into four groups: sham-operated, sham-nicotinamide, burn, and burn-nicotinamide. Rats received an intraperitoneal glucose injection (2 g/kg with (sham-nicotinamide and burn-nicotinamide groups or without (sham-operated and burn groups coadministration of nicotinamide (100 mg/kg. The results showed that the mRNA of all detoxification-related enzymes tested was detected in sham-operated skin but not in burned skin. The clearance of nicotinamide and N1-methylnicotinamide in burned rats was significantly decreased compared with that in sham-operated rats. After glucose loading, burn group showed significantly higher plasma insulin levels with a lower muscle glycogen level than that of sham-operated and sham-nicotinamide groups, although there were no significant differences in blood glucose levels over time between groups. More profound changes in plasma H2O2 and insulin levels were observed in burn-nicotinamide group. It may be concluded that decreased skin detoxification may increase the risk for oxidative stress and insulin resistance.

  5. Effect of Aging on Fracture Toughness and Stress Corrosion Cracking Resistance of Forged 7475 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    LI Hongying; GENG Jinfeng; DONG Xianjuan; WANG Changjian; ZHENG Feng

    2007-01-01

    The effects of two-stage aging and retrogression and reaging heat treatment on the fracture toughness and stress corrosion cracking resistance of 7475 alloy were studied. The fracture toughness, conductivity and strength of samples of nine groups under duplex aging conditions and three retrogression and reaging heat treatments were also measured. Incorporating the microstructure and property, we found that when the condition of the first order aging kept identical, the fracture toughness and stress corrosion cracking resistance increase with aging time and the second aging temperature. The optimal treatment conditions are (115℃×7h+185℃×13h) among all tested two-stage aging treatments.Although the 7475 alloy treated by RRA method shows the highest strength and its stress corrosion cracking resistance after twenty minutes retrogression can also reach the same level as those by the optimal treatment of (115℃×7h+185℃×13h),the fracture toughness is even low.

  6. No trade-off between growth rate and temperature stress resistance in four insect species.

    Directory of Open Access Journals (Sweden)

    Isabell Karl

    Full Text Available Although fast growth seems to be generally favored by natural selection, growth rates are rarely maximized in nature. Consequently, fast growth is predicted to carry costs resulting in intrinsic trade-offs. Disentangling such trade-offs is of great ecological importance in order to fully understand the prospects and limitations of growth rate variation. A recent study provided evidence for a hitherto unknown cost of fast growth, namely reduced cold stress resistance. Such relationships could be especially important under climate change. Against this background we here investigate the relationships between individual larval growth rate and adult heat as well as cold stress resistance, using eleven data sets from four different insect species (three butterfly species: Bicyclus anynana, Lycaena tityrus, Pieris napi; one Dipteran species: Protophormia terraenovae. Despite using different species (and partly different populations within species and an array of experimental manipulations (e.g. different temperatures, photoperiods, feeding regimes, inbreeding levels, we were not able to provide any consistent evidence for trade-offs between fast growth and temperature stress resistance in these four insect species.

  7. Local silencing controls the oxidative stress response and the multidrug resistance in Candida glabrata.

    Science.gov (United States)

    Orta-Zavalza, Emmanuel; Guerrero-Serrano, Gehenna; Gutiérrez-Escobedo, Guadalupe; Cañas-Villamar, Israel; Juárez-Cepeda, Jacqueline; Castaño, Irene; De Las Peñas, Alejandro

    2013-06-01

    In Candida glabrata, the sirtuins Sir2 and Hst1 control the expression of a wide number of genes including adhesins required for host colonization and niacin transporters needed for growth. Given that these sirtuins can be inactivated during infection, we asked if their inhibition could modify the response of C. glabrata to other stressful conditions. Here, we found that deletion of HST1 decreases susceptibility of C. glabrata to fluconazole and hydrogen peroxide. The transcription factor Pdr1 and the ABC transporter Cdr1 mediated the fluconazole resistance phenotype of the hst1Δ cells, whereas the transcriptional activator Msn4 and the catalase Cta1 are necessary to provide oxidative stress resistance. We show that the transcription factor Sum1 interacts with Hst1 and participate in the regulation of these genes. Interestingly, even though C. glabrata and Saccharomyces cerevisiae are closely related phylogenetically, deletion of HST1 decreased susceptibility to fluconazole and hydrogen peroxide only in C. glabrata but not in S. cerevisiae, indicating a different transcriptional control by two similar sirtuins. Our findings suggest that Hst1 acts as a regulator of stress resistance associated-genes. PMID:23651300

  8. Induction of Drought Stress Resistance by Multi-Functional PGPR Bacillus licheniformis K11 in Pepper.

    Science.gov (United States)

    Lim, Jong-Hui; Kim, Sang-Dal

    2013-06-01

    Drought stress is one of the major yield affecting factor for pepper plant. The effects of PGPRs were analyzed in relation with drought resistance. The PGPRs inoculated pepper plants tolerate the drought stress and survived as compared to non-inoculated pepper plants that died after 15 days of drought stress. Variations in protein and RNA accumulation patterns of inoculated and non-inoculated pepper plants subjected to drought conditions for 10 days were confirmed by two dimensional polyacrylamide gel electrophoresis (2D-PAGE) and differential display PCR (DD-PCR), respectively. A total of six differentially expressed stress proteins were identified in the treated pepper plants by 2D-PAGE. Among the stress proteins, specific genes of Cadhn, VA, sHSP and CaPR-10 showed more than a 1.5-fold expressed in amount in B. licheniformis K11-treated drought pepper compared to untreated drought pepper. The changes in proteins and gene expression patterns were attributed to the B. licheniformis K11. Accordingly, auxin and ACC deaminase producing PGPR B. licheniformis K11 could reduce drought stress in drought affected regions without the need for overusing agrochemicals and chemical fertilizer. These results will contribute to the development of a microbial agent for organic farming by PGPR. PMID:25288947

  9. Induction of Drought Stress Resistance by Multi-Functional PGPR Bacillus licheniformis K11 in Pepper

    Directory of Open Access Journals (Sweden)

    Jong-Hui Lim

    2013-06-01

    Full Text Available Drought stress is one of the major yield affecting factor for pepper plant. The effects of PGPRs were analyzed in relation with drought resistance. The PGPRs inoculated pepper plants tolerate the drought stress and survived as compared to non-inoculated pepper plants that died after 15 days of drought stress. Variations in protein and RNA accumulation patterns of inoculated and non-inoculated pepper plants subjected to drought conditions for 10 days were confirmed by two dimensional polyacrylamide gel electrophoresis (2D-PAGE and differential display PCR (DD-PCR, respectively. A total of six differentially expressed stress proteins were identified in the treated pepper plants by 2D-PAGE. Among the stress proteins, specific genes of Cadhn, VA, sHSP and CaPR-10 showed more than a 1.5-fold expressed in amount in B. licheniformis K11-treated drought pepper compared to untreated drought pepper. The changes in proteins and gene expression patterns were attributed to the B. licheniformis K11. Accordingly, auxin and ACC deaminase producing PGPR B. licheniformis K11 could reduce drought stress in drought affected regions without the need for overusing agrochemicals and chemical fertilizer. These results will contribute to the development of a microbial agent for organic farming by PGPR.

  10. Investigation into the resistance of lactoperoxidase tolerant Escherichia coli mutants to different forms of oxidative stress.

    Science.gov (United States)

    De Spiegeleer, Philipp; Vanoirbeek, Kristof; Lietaert, Annelies; Sermon, Jan; Aertsen, Abram; Michiels, Chris W

    2005-11-15

    Six lactoperoxidase tolerant Escherichia coli transposon mutants isolated and characterized in an earlier study, and some newly constructed double mutants, were subjected to peroxide, superoxide and hypochlorite stress, and their inactivation was compared to that of the wild type strain MG1655. Knock out mutants of waaQ and waaO, which owed their lactoperoxidase tolerance to an impaired outer membrane permeability due to a reduced porin content, also exhibited higher resistance to hypochlorite, as did a knock-out strain of lrp, encoding a regulatory protein affecting a wide range of cellular functions. Unlike the outer membrane mutants however, the lrp strain was also more resistant to t-butyl hydroperoxide, but more susceptible to the superoxide generating compound plumbagin. Finally, a lactoperoxidase tolerant knock-out strain of ulaA, involved in ascorbic acid uptake, did not show resistance to any of the other oxidants. The possible modes of action of these different oxidants are discussed.

  11. Influence of neighboring plants on shading stress resistance and recovery of eelgrass, Zostera marina L.

    Directory of Open Access Journals (Sweden)

    Camilla Gustafsson

    Full Text Available Stressful environments may enhance the occurrence of facilitative interspecific interactions between plants. In several regions, Zostera marina occurs in mixed assemblages. However, the potential effects of plant diversity on stress responses and stability properties of Z. marina are poorly understood. We investigated the resistance and recovery of Z. marina subjected to shading (1 mo in a field experiment lasting 2.5 mo. We shaded Z. marina planted in mono- and polycultures (Potamogeton perfoliatus, P. pectinatus, P. filiformis in a factorial design (Shading×Richness at 2 m depth. We estimated the resistance and recovery of Z. marina by measuring four response variables. Polyculture Z. marina lost proportionally less biomass than monocultures, thus having a greater resistance to shading. In contrast, after a 1 mo recovery period, monocultures exhibited higher biomass gain, and a faster recovery than polycultures. Our results suggest that plant species richness enhances the resistance of Z. marina through facilitative mechanisms, while the faster recovery in monocultures is possibly due to interspecific competition. Our results highlight the need of a much better understanding of the effects of interspecific interactions on ecosystem processes in mixed seagrass meadows, and the preservation of diverse plant assemblages to maintain ecosystem functioning.

  12. Enhanced stress resistance of Deinococcus radiodurans cells in the dried state

    Science.gov (United States)

    Bauermeister, Anja; Moeller, Ralf; Reitz, Guenther; Billi, Daniela; Rettberg, Petra

    Liquid water is often regarded as a pre-requisite for life as we know it. However, some organisms can survive prolonged periods in a desiccated state and seem to resist other environmental stres-sors even better when water is absent. We tested this observation in Deinococcus radiodurans, a non-sporeforming soil bacterium well-known for its outstanding resistance to DNA damaging stressors, including high doses of UV and ionizing radiation, oxidants, and desiccation. Due to its polyextremophilic characteristics it has been regarded as a model organism in astrobiological research. To determine if the cellular changes imposed by the removal of water have an effect on the stress resistance of D. radiodurans, we compared the survival capacity of dried cells with that of hydrated cells after exposure to mono-and polychromatic UV radiation, -radiation, and heat shock (85C). In all cases, resistance was enhanced in dried cells. It is suggested that these effects are mainly due to a reduced oxidative stress in dried cells, as the metabolism is shut down and radical diffusion is very limited. Hence, desiccating conditions as encountered in space vacuum or on arid planets such as Mars may be beneficial instead of detrimental to the survival of some polyextremophilic microbes. Ongoing experiments aim to evaluate damage at a subcellular level in dried and hydrated cells after exposure to irradiation or heat shock.

  13. Calculation of Local Stress and Fatigue Resistance due to Thermal Stratification on Pressurized Surge Line Pipe

    International Nuclear Information System (INIS)

    Thermal stratification introduces thermal shock effect which results in local stress and fatigue problems that must be considered in the design of nuclear power plant components. Local stress and fatigue calculation were performed on the Pressurize Surge Line piping system of the Pressurize Water Reactor of the Nuclear Power Plant. Analysis was done on the operating temperature between 177 to 343 deg. C and the operating pressure of 16 MPa (160 Bar). The stagnant and transient condition with two kinds of stratification model has been evaluated by the two dimensional finite elements method using the ANSYS program. Evaluation of fatigue resistance is developed based on the maximum local stress using the ASME standard Code formula. Maximum stress of 427 MPa occurred at the upper side of the top half of hot fluid pipe stratification model in the transient case condition. The evaluation of the fatigue resistance is performed on 500 operating cycles in the life time of 40 years and giving the usage value of 0,64 which met to the design requirement for class 1 of nuclear component. The out surge transient were the most significant case in the localized effects due to thermal stratification.

  14. A glycine betaine importer limits Salmonella stress resistance and tissue colonization by reducing trehalose production.

    Science.gov (United States)

    Pilonieta, M Carolina; Nagy, Toni A; Jorgensen, Dana R; Detweiler, Corrella S

    2012-04-01

    Mechanisms by which Salmonella establish chronic infections are not well understood. Microbes respond to stress by importing or producing compatible solutes, small molecules that stabilize proteins and lipids. The Salmonella locus opuABCD (also called OpuC) encodes a predicted importer of the compatible solute glycine betaine. Under stress conditions, if glycine betaine cannot be imported, Salmonella enterica produce the disaccharide trehalose, a highly effective compatible solute. We demonstrate that strains lacking opuABCD accumulate more trehalose under stress conditions than wild-type strains. ΔopuABCD mutant strains are more resistant to high-salt, low-pH and -hydrogen peroxide, conditions that mimic aspects of innate immunity, in a trehalose-dependent manner. In addition, ΔopuABCD mutant strains require the trehalose production genes to out-compete wild-type strains in mice and macrophages. These data suggest that in the absence of opuABCD, trehalose accumulation increases bacterial resistance to stress in broth and mice. Thus, opuABCD reduces bacterial colonization via a mechanism that limits trehalose production. Mechanisms by which microbes limit disease may reveal novel pathways as therapeutic targets.

  15. Effect of stress and strain on corrosion resistance of duplex stainless steel

    International Nuclear Information System (INIS)

    The interplay of the mechanical and electrochemical phenomena has been a subject of active research. In this paper, corrosion resistance studies about SAF2205 and SAF2507 duplex stainless steel were carried out under elastic stress applied (100 MPa, 300 MPa, 500 MPa) and pre-strain (5%, 10%, 15%) in 3.5% NaCl and 2 mol/L HCl solution. Potentiodynamic anodic polarization study revealed that corrosion resistance of SAF2205 duplex stainless steel decreases slightly with increasing of elastic stress level and noticeably with increasing of pre-strained level. Scanning electron microscopy investigation on surface of the electrochemical tested SAF2205 duplex stainless steel samples indicated that pitting is always located in austenite grains when pre-strain level is below 5% (including different elastic stress level) and located on intersection of ferrite and austenite grain when pre-strain level is above 5%. For SAF2507 duplex stainless steel, elastic stress and pre-strain have no effect on general corrosion and pitting corrosion. Based on deformation mechanism of duplex structure and the relationship of mechanical load and corrosion potential, Pitting corrosion behavior of duplex stainless steel is explained and discussed

  16. Monascus-fermented dioscorea enhances oxidative stress resistance via DAF-16/FOXO in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Yeu-Ching Shi

    Full Text Available BACKGROUND: Monascus-fermented products are mentioned in an ancient Chinese pharmacopoeia of medicinal food and herbs. Monascus-fermented products offer valuable therapeutic benefits and have been extensively used in East Asia for several centuries. Several biological activities of Monascus-fermented products were recently described, and the extract of Monascus-fermented products showed strong antioxidant activity of scavenging DPPH radicals. To evaluate whether Monascus-fermented dioscorea products have potential as nutritional supplements, Monascus-fermented dioscorea's modulation of oxidative-stress resistance and associated regulatory mechanisms in Caenorhabditis elegans were investigated. PRINCIPAL FINDINGS: We examined oxidative stress resistance of the ethanol extract of red mold dioscorea (RMDE in C. elegans, and found that RMDE-treated wild-type C. elegans showed an increased survival during juglone-induced oxidative stress compared to untreated controls, whereas the antioxidant phenotype was absent from a daf-16 mutant. In addition, the RMDE reduced the level of intracellular reactive oxygen species in C. elegans. Finally, the RMDE affected the subcellular distribution of the FOXO transcription factor, DAF-16, in C. elegans and induced the expression of the sod-3 antioxidative gene. CONCLUSIONS: These findings suggest that the RMDE acts as an antioxidative stress agent and thus may have potential as a nutritional supplement. Further studies in C. elegans suggest that the antioxidant effect of RMDE is mediated via regulation of the DAF-16/FOXO-dependent pathway.

  17. Enhancement of stress resistance of the guppy Poecilia reticulata through feeding with vitamin C supplement

    OpenAIRE

    Lim, L C; Dhert, P.; Chew, W.Y.; Dermaux, V.; Nelis, H.; Sorgeloos, P.

    2002-01-01

    This study investigated the use of vitamin C supplement in formulated diets and live Artemia juveniles to enhance the stress resistance of the guppy Poecilia reticulata. To evaluate the stress resistance, fish were subjected to osmotic shock in pre-aerated water containing 35 ppt sodium chloride. Ascorbyl acid-poly phosphate and ascorbyl palmitate were used as vitamin C sources for formulated diets and live Artemia juveniles, respectively. Results showed that guppies fed moist formulated diet...

  18. THE TSC COMPLEX IS REQUIRED FOR THE BENEFITS OF DIETARY PROTEIN RESTRICTION ON STRESS RESISTANCE IN VIVO

    OpenAIRE

    Eylul Harputlugil; Christopher Hine; Dorathy Vargas; Lauren Robertson; Brendan D. Manning; James R. Mitchell

    2014-01-01

    Protein restriction (PR) is important for the benefits of dietary restriction on longevity and stress resistance, but relevant nutrient sensors and downstream effectors in mammals remain poorly defined. We used PR-mediated protection from hepatic ischemia reperfusion injury to probe genetic requirements for the evolutionarily conserved nutrient sensors GCN2 and mTORC1 in stress resistance. One week of PR reduced free amino acids and circulating growth factors, activating GCN2 and mTORC1 repre...

  19. Methionine Metabolism Alters Oxidative Stress Resistance via the Pentose Phosphate Pathway.

    Science.gov (United States)

    Campbell, Kate; Vowinckel, Jakob; Keller, Markus A; Ralser, Markus

    2016-04-01

    Nutrient uptake and metabolism have a significant impact on the way cells respond to stress. The amino acid methionine is, in particular, a key player in the oxidative stress response, and acting as a reactive oxygen species scavenger, methionine is implicated in caloric restriction phenotypes and aging. We here provide evidence that some effects of methionine in stress situations are indirect and caused by altered activity of the nicotinamide adenine dinucleotide phosphate (NADPH) producing oxidative part of the pentose phosphate pathway (PPP). In Saccharomyces cerevisiae, both methionine prototrophic (MET15) and auxotrophic (met15Δ) cells supplemented with methionine showed an increase in PPP metabolite concentrations downstream of the NADPH producing enzyme, 6-phosphogluconate dehydrogenase. Proteomics revealed this enzyme to also increase in expression compared to methionine self-synthesizing cells. Oxidant tolerance was increased in cells preincubated with methionine; however, this effect was abolished when flux through the oxidative PPP was prevented by deletion of its rate limiting enzyme, ZWF1. Stress resistance phenotypes that follow methionine supplementation hence involve the oxidative PPP. Effects of methionine on oxidative metabolism, stress signaling, and aging have thus to be seen in the context of an altered activity of this NADP reducing pathway.

  20. EXPRESSION OF BACTERIAL PROTEIN-A IN TOBACCO LEADS TO ENHANCED RESISTANCE TO STRESS CONDITIONS

    Directory of Open Access Journals (Sweden)

    Chaitali Roy

    2014-08-01

    Full Text Available Tobacco is the most commonly used plant for expression of transgenes from a variety of organisms because it can be easily grown and transformed, it provides abundant amounts of fresh tissue and has a well-established cell culture system. As bacterial enzymes can be synthesized in tobacco, here we explore the possibility of in planta expression of staphylococcal protein-A(PA which is an antibody, an important group among biopharmaceuticals. In our study we have shown that the tobacco plants harboring PA gene could combat the crown gall infection and also effective in resisting abiotic stress conditions. Transgenic plants when subjected to interact with wild variety of Agrobacterium shows its enhanced capability to resist the gall formation. And when transgenic tobacco plants were grown in presence of 200mM NaCl and/or MG(Methylglyoxal solution, shows their increased tolerance towards salinity stress and high MG stress. So far transgenic tobacco plants are concerned, improvements in the expression of recombinant proteins and their recovery from tobacco may also enhance production and commercial use of this protein.

  1. Variation in adult life history and stress resistance across five species of Drosophila

    Indian Academy of Sciences (India)

    N. Sharmila Bharathi; N. G. Prasad; Mallikarjun Shakarad; Amitabh Joshi

    2003-12-01

    species. In terms of overall performance, the laboratory population of D. melanogaster was clearly superior, under laboratory conditions, to the other four species if adult lifespan, lifetime fecundity, average daily fecundity, and absolute starvation and desiccation resistance are considered. This finding is contrary to several recent reports of substantially higher adult lifespan and stress resistance in recently wild-caught flies, relative to flies maintained for a long time in discrete-generation laboratory cultures. Possible explanations for these apparent anomalies are discussed in the context of the differing selection pressures likely to be experienced by Drosophila populations in laboratory versus wild environments.

  2. Overexpression of an ABA biosynthesis gene using a stress-inducible promoter enhances drought resistance in petunia

    OpenAIRE

    Estrada-Melo, Alejandro C; Chao,; Reid, Michael S; Cai-Zhong Jiang

    2015-01-01

    The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations. Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development. We overexpressed the tomato NCED (LeNCED1) in petunia plants under the control of a stress-inducible promoter, rd29A. Under water stress...

  3. Compounds Triggering ER Stress Exert Anti-Melanoma Effects and Overcome BRAF Inhibitor Resistance.

    Science.gov (United States)

    Cerezo, Michaël; Lehraiki, Abdelali; Millet, Antoine; Rouaud, Florian; Plaisant, Magali; Jaune, Emilie; Botton, Thomas; Ronco, Cyril; Abbe, Patricia; Amdouni, Hella; Passeron, Thierry; Hofman, Veronique; Mograbi, Baharia; Dabert-Gay, Anne-Sophie; Debayle, Delphine; Alcor, Damien; Rabhi, Nabil; Annicotte, Jean-Sébastien; Héliot, Laurent; Gonzalez-Pisfil, Mariano; Robert, Caroline; Moréra, Solange; Virougoux, Armelle; Gual, Philippe; Ali, Maruf M U; Bertolotto, Corine; Hofman, Paul; Ballotti, Robert; Benhida, Rachid; Rocchi, Stéphane

    2016-06-13

    We have discovered and developed a series of molecules (thiazole benzenesulfonamides). HA15, the lead compound of this series, displayed anti-cancerous activity on all melanoma cells tested, including cells isolated from patients and cells that developed resistance to BRAF inhibitors. Our molecule displayed activity against other liquid and solid tumors. HA15 also exhibited strong efficacy in xenograft mouse models with melanoma cells either sensitive or resistant to BRAF inhibitors. Transcriptomic, proteomic, and biochemical studies identified the chaperone BiP/GRP78/HSPA5 as the specific target of HA15 and demonstrated that the interaction increases ER stress, leading to melanoma cell death by concomitant induction of autophagic and apoptotic mechanisms.

  4. FUNCTION OF HYDRAULIC AND CHEMICAL WATER STRESS SIGNALIZATION IN EVALUATION OF DROUGHT RESISTANCE OF JUVENILE PLANTS

    Directory of Open Access Journals (Sweden)

    K OLŠOVSKÁ

    2002-05-01

    Full Text Available In laboratory hydroponic experiments with spring barley genotypes the juvenile plants with 5 leaves were tested for their physiological responses to osmotic stress evoked by blocking the water uptake in roots by polyethylenglycol (PEG-6000 and to exogenous abscisic acid (ABA applied in the nutrient solution which inhibits the stomata opening. Results from the measurements of leaf diffusion resistance, relative water content, transpiration and leaf elongation rates show dominant role of chemical signalization drought from root environment and of stomata in the regulation of water loss as well as sensitiveness of leaf elongation to lowered water availability. Maintenance of water content and turgor in the leaf tissues resulted from expression of morphological and physiological mechanisms of resistance and tolerance to drought different from that in mature plants which might be useful in the screening genotypes with different level of drought tolerance.

  5. Acute exercise improves endothelial function despite increasing vascular resistance during stress in smokers and nonsmokers.

    Science.gov (United States)

    Rooks, Cherie R; McCully, Kevin K; Dishman, Rod K

    2011-09-01

    The present study examined the effect of acute exercise on flow mediated dilation (FMD) and reactivity to neurovascular challenges among female smokers and nonsmokers. FMD was determined by arterial diameter, velocity, and blood flow measured by Doppler ultrasonography after forearm occlusion. Those measures and blood pressure and heart rate were also assessed in response to forehead cold and the Stroop Color-Word Conflict Test (CWT) before and after 30 min of rest or an acute bout of cycling exercise (∼50% VO₂ peak). Baseline FMD and stress responses were not different between smokers and nonsmokers. Compared to passive rest, exercise increased FMD and decreased arterial velocity and blood flow responses during the Stroop CWT and forehead cold in both groups. Overall, acute exercise improved endothelial function among smokers and nonsmokers despite increasing vascular resistance and reducing limb blood flow during neurovascular stress. PMID:21457274

  6. Resistance of LaCl3 to Oxidative Stress Induced by 2, 4-Dichlorophenoxy

    Institute of Scientific and Technical Information of China (English)

    Jia Yanxia; Gao Yongsheng; Zeng Fuli

    2005-01-01

    Cucumber seedlings were sprayed with different concentrations of LaCl3 for 3 d continuously. After 7 d of this treatment, the plants were treated with 1200 mg·L-1 2,4-dichlorophennoxy(2,4-D) for 24 h. The leaves were harvested and rinsed with 5 mmol · L-1 EDTA. The concentrations of photosynthetic pigments, soluble protein and metabolites related to oxidative stress and the activities of antioxidant enzymes in leaves were assayed. The results show that the treatment with appropriate concentration of LaCl3 has resistant effect on oxidative stress induced by 2, 4-D. Proper concentration of LaCl3 promotes the activity of antioxidant system in plants and alleviates the damage caused by 2, 4-D.

  7. Flurbiprofen ameliorated obesity by attenuating leptin resistance induced by endoplasmic reticulum stress.

    Science.gov (United States)

    Hosoi, Toru; Yamaguchi, Rie; Noji, Kikuko; Matsuo, Suguru; Baba, Sachiko; Toyoda, Keisuke; Suezawa, Takahiro; Kayano, Takaaki; Tanaka, Shinpei; Ozawa, Koichiro

    2014-03-01

    Endoplasmic reticulum (ER) stress, caused by the accumulation of unfolded proteins, is involved in the development of obesity. We demonstrated that flurbiprofen, a nonsteroidal anti-inflammatory drug (NSAID), exhibited chaperone activity, which reduced protein aggregation and alleviated ER stress-induced leptin resistance, characterized by insensitivity to the actions of the anti-obesity hormone leptin. This result was further supported by flurbiprofen attenuating high-fat diet-induced obesity in mice. The other NSAIDs tested did not exhibit such effects, which suggested that this anti-obesity action is mediated independent of NSAIDs. Using ferriteglycidyl methacrylate beads, we identified aldehyde dehydrogenase as the target of flurbiprofen, but not of the other NSAIDs. These results suggest that flurbiprofen may have unique pharmacological properties that reduce the accumulation of unfolded proteins and may represent a new class of drug for the fundamental treatment of obesity.

  8. The Batten disease gene CLN3 confers resistance to endoplasmic reticulum stress induced by tunicamycin

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dan, E-mail: danw@bjmu.edu.cn [Department of Medical Genetics, Peking University Health Science Center, No 38 Xueyuan Road, Haidian district, Beijing 100191 (China); Liu, Jing; Wu, Baiyan [Department of Medical Genetics, Peking University Health Science Center, No 38 Xueyuan Road, Haidian district, Beijing 100191 (China); Tu, Bo; Zhu, Weiguo [Department of Biochemistry and Molecular Biology, Peking University Health Science Center, No 38 Xueyuan Road, Haidian district, Beijing 100191 (China); Luo, Jianyuan, E-mail: jluo@som.umaryland.edu [Department of Medical Genetics, Peking University Health Science Center, No 38 Xueyuan Road, Haidian district, Beijing 100191 (China); Department of Medical and Research Technology, School of Medicine, University of Maryland, Baltimore 21201 (United States)

    2014-04-25

    Highlights: • The work reveals a protective properties of CLN3 towards TM-induced apoptosis. • CLN3 regulates expression of the GRP78 and the CHOP in response to the ER stress. • CLN3 plays a specific role in the ERS response. - Abstract: Mutations in CLN3 gene cause juvenile neuronal ceroid lipofuscinosis (JNCL or Batten disease), an early-onset neurodegenerative disorder that is characterized by the accumulation of ceroid lipofuscin within lysosomes. The function of the CLN3 protein remains unclear and is presumed to be related to Endoplasmic reticulum (ER) stress. To investigate the function of CLN3 in the ER stress signaling pathway, we measured proliferation and apoptosis in cells transfected with normal and mutant CLN3 after treatment with the ER stress inducer tunicamycin (TM). We found that overexpression of CLN3 was sufficient in conferring increased resistance to ER stress. Wild-type CLN3 protected cells from TM-induced apoptosis and increased cell proliferation. Overexpression of wild-type CLN3 enhanced expression of the ER chaperone protein, glucose-regulated protein 78 (GRP78), and reduced expression of the proapoptotic protein CCAAT/-enhancer-binding protein homologous protein (CHOP). In contrast, overexpression of mutant CLN3 or siRNA knockdown of CLN3 produced the opposite effect. Together, our data suggest that the lack of CLN3 function in cells leads to a failure of management in the response to ER stress and this may be the key deficit in JNCL that causes neuronal degeneration.

  9. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

    Science.gov (United States)

    Vaziri, Nosratola D; Liu, Shu-Man; Lau, Wei Ling; Khazaeli, Mahyar; Nazertehrani, Sohrab; Farzaneh, Seyed H; Kieffer, Dorothy A; Adams, Sean H; Martin, Roy J

    2014-01-01

    Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control) or high fermentable fiber (amylose maize resistant starch, HAM-RS2) for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.

  10. High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Nosratola D Vaziri

    Full Text Available Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control or high fermentable fiber (amylose maize resistant starch, HAM-RS2 for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.

  11. Analysis of drought resistance HVA1 gene under drought stress in different Poa pratensis cultivars

    Institute of Scientific and Technical Information of China (English)

    WU Yanhua; CHEN Yajun; SHEN Fengjuan; SUN Xiaoyan

    2007-01-01

    Total RNA from leaves of Poa pratensis cultivars under drought stress was extracted for reversing transcription to cDNA and then cDNA as template for PCR reaction by designing primer of cds of Hordeum valgare HVA1 drought resistance gene from GenBank. The amplified products were positive recon identified by using procedures of recovery, connection, transformation and enzyme separation. The length of cloned gene sequence was 324 bp, identity reached 79.27% with Barley HVA1 gene that meaned the cloned gene sequence was the partial HVA1 gene of Poa pratensis.

  12. Osmoregulation Mechanism of Drought Stress and Genetic Engineering Strategies for Improving Drought Resistance in Plants

    Institute of Scientific and Technical Information of China (English)

    Du Jinyou; Chen Xiaoyang; Li Wei; Gao Qiong

    2004-01-01

    Drought, one of the main adverse environmental factors, obviously affected plant growth and development. Many adaptive strategies have been developed in plants for coping with drought or water stress, among which osmoregulation is one of the important factors of plant drought tolerance. Many substances play important roles in plant osmoregulation for drought resistance, including proline, glycine betaine, Lea proteins and soluble sugars such as levan, trehalose, sucrose, etc. The osmoregulation mechanism and the genetic engineering of plant drought-tolerance are reviewed in this paper.

  13. Contribution to surface physicochemical factors to stress corrosion resistance in stainless steels

    International Nuclear Information System (INIS)

    The author of this research thesis first presents and discusses the various aspects of stress corrosion cracking of Fe-Cr-Ni alloys of high purity: experimental conditions (alloy elaboration, sample preparation), corrosion results (Schaeffer diagram, crack morphology, intergranular corrosion), influence of addition elements in ferritic alloys. He reports an electrochemical study of stainless steels in magnesium chloride (experimental conditions, influence of metallurgic and environmental parameters on polarization resistance, current-voltage curves), and an analytical study of layers formed in the magnesium chloride

  14. 25-Hydroxyvitamin D3-deficiency enhances oxidative stress and corticosteroid resistance in severe asthma exacerbation.

    Directory of Open Access Journals (Sweden)

    Nan Lan

    Full Text Available Oxidative stress plays a significant role in exacerbation of asthma. The role of vitamin D in oxidative stress and asthma exacerbation remains unclear. We aimed to determine the relationship between vitamin D status and oxidative stress in asthma exacerbation. Severe asthma exacerbation patients with 25-hydroxyvitamin D3-deficiency (V-D deficiency or 25-hydroxyvitamin D-sufficiency (V-D sufficiency were enrolled. Severe asthma exacerbation with V-D-deficiency showed lower forced expiratory volume in one second (FEV1 compared to that with V-D-sufficiency. V-D-deficiency intensified ROS release and DNA damage and increased TNF-α, OGG1 and NFκB expression and NFκB phosphorylation in severe asthma exacerbation. Supplemental vitamin D3 significantly increased the rates of FEV1 change and decreased ROS and DNA damage in V-D-deficiency. Vitamin D3 inhibited LPS-induced ROS and DNA damage and were associated with a decline in TNF-α and NFκB in epithelial cells. H2O2 reduces nuclear translocation of glucocorticoid receptors in airway epithelial cell lines. V-D pretreatment enhanced the dexamethasone-induced nuclear translocation of glucocorticoid receptors in airway epithelial cell lines and monocytes from 25-hydroxyvitamin D3-deficiency asthma patients. These findings indicate that V-D deficiency aggravates oxidative stress and DNA damage, suggesting a possible mechanism for corticosteroid resistance in severe asthma exacerbation.

  15. 25-Hydroxyvitamin D3-deficiency enhances oxidative stress and corticosteroid resistance in severe asthma exacerbation.

    Science.gov (United States)

    Lan, Nan; Luo, Guangyan; Yang, Xiaoqiong; Cheng, Yuanyuan; Zhang, Yun; Wang, Xiaoyun; Wang, Xing; Xie, Tao; Li, Guoping; Liu, Zhigang; Zhong, Nanshan

    2014-01-01

    Oxidative stress plays a significant role in exacerbation of asthma. The role of vitamin D in oxidative stress and asthma exacerbation remains unclear. We aimed to determine the relationship between vitamin D status and oxidative stress in asthma exacerbation. Severe asthma exacerbation patients with 25-hydroxyvitamin D3-deficiency (V-D deficiency) or 25-hydroxyvitamin D-sufficiency (V-D sufficiency) were enrolled. Severe asthma exacerbation with V-D-deficiency showed lower forced expiratory volume in one second (FEV1) compared to that with V-D-sufficiency. V-D-deficiency intensified ROS release and DNA damage and increased TNF-α, OGG1 and NFκB expression and NFκB phosphorylation in severe asthma exacerbation. Supplemental vitamin D3 significantly increased the rates of FEV1 change and decreased ROS and DNA damage in V-D-deficiency. Vitamin D3 inhibited LPS-induced ROS and DNA damage and were associated with a decline in TNF-α and NFκB in epithelial cells. H2O2 reduces nuclear translocation of glucocorticoid receptors in airway epithelial cell lines. V-D pretreatment enhanced the dexamethasone-induced nuclear translocation of glucocorticoid receptors in airway epithelial cell lines and monocytes from 25-hydroxyvitamin D3-deficiency asthma patients. These findings indicate that V-D deficiency aggravates oxidative stress and DNA damage, suggesting a possible mechanism for corticosteroid resistance in severe asthma exacerbation.

  16. Relationship between calcium decoding elements and plant abiotic-stress resistance

    Directory of Open Access Journals (Sweden)

    Wei-Yi Song, Zheng-Bin Zhang, Hong-Bo Shao, Xiu-Lin Guo, Hong-Xing Cao, Hong-Bin Zhao, Zheng-Yan Fu, Xiao-Jun Hu

    2008-01-01

    Full Text Available Serving as an important second messenger, calcium ion has unique properties and universal ability to transmit diverse signals that trigger primary physiological actions in cells in response to hormones, pathogens, light, gravity, and stress factors. Being a second messenger of paramount significance, calcium is required at almost all stages of plant growth and development, playing a fundamental role in regulating polar growth of cells and tissues and participating in plant adaptation to various stress factors. Many researches showed that calcium signals decoding elements are involved in ABA-induced stomatal closure and plant adaptation to drought, cold, salt and other abiotic stresses. Calcium channel proteins like AtTPC1 and TaTPC1 can regulate stomatal closure. Recently some new studies show that Ca2+ is dissolved in water in the apoplast and transported primarily from root to shoot through the transpiration stream. The oscillating amplitudes of [Ca2+]o and [Ca2+]i are controlled by soil Ca2+ concentrations and transpiration rates. Because leaf water use efficiency (WUE is determined by stomatal closure and transpiration rate, so there may be a close relationship between Ca2+ transporters and stomatal closure as well as WUE, which needs to be studied. The selection of varieties with better drought resistance and high WUE plays an increasing role in bio-watersaving in arid and semi-arid areas on the globe. The current paper reviews the relationship between calcium signals decoding elements and plant drought resistance as well as other abiotic stresses for further study.

  17. Glucocorticoid Fast Feedback Inhibition of Stress-Induced ACTH Secretion in the Male Rat: Rate Independence and Stress-State Resistance.

    Science.gov (United States)

    Osterlund, Chad D; Rodriguez-Santiago, Mariana; Woodruff, Elizabeth R; Newsom, Ryan J; Chadayammuri, Anjali P; Spencer, Robert L

    2016-07-01

    Normal glucocorticoid secretion is critical for physiological and mental health. Glucocorticoid secretion is dynamically regulated by glucocorticoid-negative feedback; however, the mechanisms of that feedback process are poorly understood. We assessed the temporal characteristics of glucocorticoid-negative feedback in vivo using a procedure for drug infusions and serial blood collection in unanesthetized rats that produced a minimal disruption of basal ACTH plasma levels. We compared the negative feedback effectiveness present when stress onset coincides with corticosterone's (CORT) rapidly rising phase (30 sec pretreatment), high plateau phase (15 min pretreatment), or restored basal phase (60 min pretreatment) as well as effectiveness when CORT infusion occurs after the onset of stress (5 min poststress onset). CORT treatment prior to stress onset acted remarkably fast (within 30 sec) to suppress stress-induced ACTH secretion. Furthermore, fast feedback induction did not require rapid increases in CORT at the time of stress onset (hormone rate independent), and those feedback actions were relatively long lasting (≥15 min). In contrast, CORT elevation after stress onset produced limited and delayed ACTH suppression (stress state resistance). There was a parallel stress-state resistance for CORT inhibition of stress-induced Crh heteronuclear RNA in the paraventricular nucleus but not Pomc heteronuclear RNA in the anterior pituitary. CORT treatment did not suppress stress-induced prolactin secretion, suggesting that CORT feedback is restricted to the control of hypothalamic-pituitary-adrenal axis elements of a stress response. These temporal, stress-state, and system-level features of in vivo CORT feedback provide an important physiological context for ex vivo studies of molecular and cellular mechanisms of CORT-negative feedback. PMID:27145013

  18. Glucocorticoid Fast Feedback Inhibition of Stress-Induced ACTH Secretion in the Male Rat: Rate Independence and Stress-State Resistance.

    Science.gov (United States)

    Osterlund, Chad D; Rodriguez-Santiago, Mariana; Woodruff, Elizabeth R; Newsom, Ryan J; Chadayammuri, Anjali P; Spencer, Robert L

    2016-07-01

    Normal glucocorticoid secretion is critical for physiological and mental health. Glucocorticoid secretion is dynamically regulated by glucocorticoid-negative feedback; however, the mechanisms of that feedback process are poorly understood. We assessed the temporal characteristics of glucocorticoid-negative feedback in vivo using a procedure for drug infusions and serial blood collection in unanesthetized rats that produced a minimal disruption of basal ACTH plasma levels. We compared the negative feedback effectiveness present when stress onset coincides with corticosterone's (CORT) rapidly rising phase (30 sec pretreatment), high plateau phase (15 min pretreatment), or restored basal phase (60 min pretreatment) as well as effectiveness when CORT infusion occurs after the onset of stress (5 min poststress onset). CORT treatment prior to stress onset acted remarkably fast (within 30 sec) to suppress stress-induced ACTH secretion. Furthermore, fast feedback induction did not require rapid increases in CORT at the time of stress onset (hormone rate independent), and those feedback actions were relatively long lasting (≥15 min). In contrast, CORT elevation after stress onset produced limited and delayed ACTH suppression (stress state resistance). There was a parallel stress-state resistance for CORT inhibition of stress-induced Crh heteronuclear RNA in the paraventricular nucleus but not Pomc heteronuclear RNA in the anterior pituitary. CORT treatment did not suppress stress-induced prolactin secretion, suggesting that CORT feedback is restricted to the control of hypothalamic-pituitary-adrenal axis elements of a stress response. These temporal, stress-state, and system-level features of in vivo CORT feedback provide an important physiological context for ex vivo studies of molecular and cellular mechanisms of CORT-negative feedback.

  19. Amoxicillin/clavulanic acid-induced pemphigus vulgaris: case report.

    Science.gov (United States)

    Baroni, Adone; Russo, Teresa; Faccenda, Franco; Piccolo, Vincenzo

    2012-01-01

    Drug-induced pemphigus is a well-established variety of pemphigus, presenting with clinical and histopathologic features identical to idiopathic form. Medical history plays a fundamental role in the diagnosis of drug-induced pemphigus. A large variety of drugs have been implicated in its pathogenesis and they may induce acantholysis via biochemical and/or immune mechanism. We present a case of a 69-year-old woman affected by amoxicillin/clavulanic acid-induced pemphigus and discuss its pathogenetic mechanism.

  20. Folic acid induces salicylic acid-dependent immunity in Arabidopsis and enhances susceptibility to Alternaria brassicicola.

    Science.gov (United States)

    Wittek, Finni; Kanawati, Basem; Wenig, Marion; Hoffmann, Thomas; Franz-Oberdorf, Katrin; Schwab, Wilfried; Schmitt-Kopplin, Philippe; Vlot, A Corina

    2015-08-01

    Folates are essential for one-carbon transfer reactions in all organisms and contribute, for example, to de novo DNA synthesis. Here, we detected the folate precursors 7,8-dihydropteroate (DHP) and 4-amino-4-deoxychorismate (ADC) in extracts from Arabidopsis thaliana plants by Fourier transform ion cyclotron resonance-mass spectrometry. The accumulation of DHP, but not ADC, was induced after infection of plants with Pseudomonas syringae delivering the effector protein AvrRpm1. Application of folic acid or the DHP precursor 7,8-dihydroneopterin (DHN) enhanced resistance in Arabidopsis to P. syringae and elevated the transcript accumulation of the salicylic acid (SA) marker gene pathogenesis-related1 in both the treated and systemic untreated leaves. DHN- and folic acid-induced systemic resistance was dependent on SA biosynthesis and signalling. Similar to SA, folic acid application locally enhanced Arabidopsis susceptibility to the necrotrophic fungus Alternaria brassicicola. Together, the data associate the folic acid pathway with innate immunity in Arabidopsis, simultaneously activating local and systemic SA-dependent resistance to P. syringae and suppressing local resistance to A. brassicicola.

  1. Aluminium resistance requires resistance to acid stress: a case study with spinach that exudes oxalate rapidly when exposed to Al stress.

    Science.gov (United States)

    Yang, Jian Li; Zheng, Shao Jian; He, Yun Feng; Matsumoto, Hideaki

    2005-04-01

    Spinach is a vegetable with a high oxalate concentration in its tissues. Oxalate efflux from spinach (Spinacia oleracea L. cv. Quanneng) roots was rapidly stimulated (within 30 min) by aluminium (Al) treatment. The efflux was constant within 6 h, but increased with increasing Al concentration. The efflux was confined to the root tip (0-5 mm), which showed a 5-fold greater efflux than the root zone distal to the tip (5-10 mm). Oxalate efflux could not be triggered by treatment with the trivalent cation lanthanum or by phosphorus deficiency, indicating that the efflux was specific to the Al treatment. All this evidence suggested that spinach possesses Al-resistance mechanisms. However, spinach was found to be as sensitive to Al toxicity as the Al-sensitive wheat line ES8, which had no Al-dependent organic acids efflux. The Al accumulated in the apical 5 mm of the roots of spinach which was also similar to that in the Al-sensitive wheat after 24 h treatment with 50 microM AlCl(3), indicating a non-exclusion mechanism. In addition, root elongation in spinach was significantly inhibited at pH 4.5, compared with that at pH 6.5. Based on this evidence, it is concluded that the sensitivity to acid stress in spinach could mask the potential role for oxalate to protect the plant roots from Al toxicity.

  2. Biosynthesis of vitamin C by yeast leads to increased stress resistance.

    Directory of Open Access Journals (Sweden)

    Paola Branduardi

    Full Text Available BACKGROUND: In industrial large scale bio-reactions micro-organisms are generally exposed to a variety of environmental stresses, which might be detrimental for growth and productivity. Reactive oxygen species (ROS play a key role among the common stress factors--directly--through incomplete reduction of O(2 during respiration, or indirectly--caused by other stressing factors. Vitamin C or L-ascorbic acid acts as a scavenger of ROS, thereby potentially protecting cells from harmful oxidative products. While most eukaryotes synthesize ascorbic acid, yeast cells produce erythro-ascorbic acid instead. The actual importance of this antioxidant substance for the yeast is still a subject of scientific debate. METHODOLOGY/PRINCIPAL FINDINGS: We set out to enable Saccharomyces cerevisiae cells to produce ascorbic acid intracellularly to protect the cells from detrimental effects of environmental stresses. We report for the first time the biosynthesis of L-ascorbic acid from D-glucose by metabolically engineered yeast cells. The amount of L-ascorbic acid produced leads to an improved robustness of the recombinant cells when they are subjected to stress conditions as often met during industrial fermentations. Not only resistance against oxidative agents as H(2O(2 is increased, but also the tolerance to low pH and weak organic acids at low pH is increased. CONCLUSIONS/SIGNIFICANCE: This platform provides a new tool whose commercial applications may have a substantial impact on bio-industrial production of Vitamin C. Furthermore, we propose S. cerevisiae cells endogenously producing vitamin C as a cellular model to study the genesis/protection of ROS as well as genotoxicity.

  3. IbeR facilitates stress-resistance, invasion and pathogenicity of avian pathogenic Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Shaohui Wang

    Full Text Available Systemic infections by avian pathogenic Escherichia coli (APEC are economically devastating to poultry industries worldwide. IbeR, located on genomic island GimA, was shown to serve as an RpoS-like regulator in rpoS gene mutation neonatal meningitis E. coli (NMEC RS218. However, the role of IbeR in pathogenicity of APEC carrying active RpoS has not yet been investigated. We showed that the APEC IbeR could elicit antibodies in infected ducks, suggesting that IbeR might be involved in APEC pathogenicity. To investigate the function of IbeR in APEC pathogenesis, mutant and complementation strains were constructed and characterized. Inactivation of ibeR led to attenuated virulence and reduced invasion capacity towards DF-1 cells, brains and cerebrospinal fluid (CSF in vitro and in vivo. Bactericidal assays demonstrated that the mutant strain had impaired resistance to environmental stress and specific pathogen-free (SPF chicken serum. These virulence-related phenotypes were restored by genetic complementation. Quantitative real-time reverse transcription PCR revealed that IbeR controlled expression of stress-resistance genes and virulence genes, which might led to the associated virulence phenotype.

  4. Enhanced Locomotor Activity Is Required to Exert Dietary Restriction-Dependent Increase of Stress Resistance in Drosophila

    Directory of Open Access Journals (Sweden)

    Saurav Ghimire

    2015-01-01

    Full Text Available Dietary restriction (DR is known to be one of the most effective interventions to increase stress resistance, yet the mechanisms remain elusive. One of the most obvious DR-induced changes in phenotype is an increase in locomotor activity. Although it is conceptually perceivable that nutritional scarcity should prompt enhanced foraging behavior to garner additional dietary resources, the significance of enhanced movement activity has not been associated with the DR-dependent increase of stress resistance. In this study, we confirmed that flies raised on DR exhibited enhanced locomotive activity and increased stress resistance. Excision of fly wings minimized the DR-induced increase in locomotive activity, which resulted in attenuation of the DR-dependent increase of stress resistance. The possibility that wing clipping counteracts the DR by coercing flies to have more intake was ruled out since it did not induce any weight gain. Rather it was found that elimination of reactive oxygen species (ROS that is enhanced by DR-induced upregulation of expression of antioxidant genes was significantly reduced by wing clipping. Collectively, our data suggests that DR increased stress resistance by increasing the locomotor activity, which upregulated expression of protective genes including, but not limited to, ROS scavenger system.

  5. Enhanced Locomotor Activity Is Required to Exert Dietary Restriction-Dependent Increase of Stress Resistance in Drosophila.

    Science.gov (United States)

    Ghimire, Saurav; Kim, Man Su

    2015-01-01

    Dietary restriction (DR) is known to be one of the most effective interventions to increase stress resistance, yet the mechanisms remain elusive. One of the most obvious DR-induced changes in phenotype is an increase in locomotor activity. Although it is conceptually perceivable that nutritional scarcity should prompt enhanced foraging behavior to garner additional dietary resources, the significance of enhanced movement activity has not been associated with the DR-dependent increase of stress resistance. In this study, we confirmed that flies raised on DR exhibited enhanced locomotive activity and increased stress resistance. Excision of fly wings minimized the DR-induced increase in locomotive activity, which resulted in attenuation of the DR-dependent increase of stress resistance. The possibility that wing clipping counteracts the DR by coercing flies to have more intake was ruled out since it did not induce any weight gain. Rather it was found that elimination of reactive oxygen species (ROS) that is enhanced by DR-induced upregulation of expression of antioxidant genes was significantly reduced by wing clipping. Collectively, our data suggests that DR increased stress resistance by increasing the locomotor activity, which upregulated expression of protective genes including, but not limited to, ROS scavenger system.

  6. Saturated lipids decrease mitofusin 2 leading to endoplasmic reticulum stress activation and insulin resistance in hypothalamic cells.

    Science.gov (United States)

    Diaz, Brenda; Fuentes-Mera, Lizeth; Tovar, Armando; Montiel, Teresa; Massieu, Lourdes; Martínez-Rodríguez, Herminia Guadalupe; Camacho, Alberto

    2015-11-19

    Endoplasmic reticulum (ER) and mitochondria dysfunction contribute to insulin resistance generation during obesity and diabetes. ER and mitochondria interact through Mitofusin 2 (MTF2), which anchors in the outer mitochondrial and ER membranes regulating energy metabolism. Ablation of MTF2 leads to ER stress activation and insulin resistance. Here we determine whether lipotoxic insult induced by saturated lipids decreases MTF2 expression leading to ER stress response in hypothalamus and its effects on insulin sensitivity using in vitro and in vivo models. We found that lipotoxic stimulation induced by palmitic acid, but not the monounsaturated palmitoleic acid, decreases MTF2 protein levels in hypothalamic mHypoA-CLU192 cells. Also, palmitic acid incubation activates ER stress response evidenced by increase in the protein levels of GRP78/BIP marker at later stage than MTF2 downregulation. Additionally, we found that MTF2 alterations induced by palmitic, but not palmitoleic, stimulation exacerbate insulin resistance in hypothalamic cells. Insulin resistance induced by palmitic acid is prevented by pre-incubation of the anti-inflammatory and the ER stress release reagents, sodium salicylate and 4 phenylbutirate, respectively. Finally, we demonstrated that lipotoxic insult induced by high fat feeding to mice decreases MTF2 proteins levels in arcuate nucleus of hypothalamus. Our data indicate that saturated lipids modulate MTF2 expression in hypothalamus coordinating the ER stress response and the susceptibility to insulin resistance.

  7. Development of Modified 304 Stainless Steel Resistant to Stress Corrosion Cracking in Chloride Environment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This was a feasibility study for a modified 304 steel resistant to stress corrosion cracking (SCC) in aqueous environment containing chloride. SCC tests were conducted potentiostaticaly with spot-welded specimens, which had both crevice and residual stress, mainly in 3 % NaCl solution at various temperatures to determine the critical temperature for SCC at and below which the steel would not suffer from SCC. The effects of individual alloying element of silicon, manganese and copper on SCC of 18Cr-14Ni steels which phosphor content is 0.002 % and molybdenum content is 0.01 % were examined. Addition of 1 or 2 % of copper has beneficial effect on resistance to SCC, while increasing silicon or manganese content has no significant effect. Critical temperature of the steel with 0.002 % of phosphor and 2 % of copper is 150 ℃, which is markedly higher than 50 ℃ of 304L steel. However, the beneficial effect of copper is reduced with increasing phosphor content. From practical viewpoint, the modified steel with good SCC resistance should have 0.01 %-0.015 % of phosphor and 0.3 % or more of molybdenum, because it is very difficult to reduce phosphor content below 0.008 % industrially and such molybdenum content is inevitably introduced through cost-saving melting process using return steel. Aluminium is to be added as another alloying element and 3 % of aluminium combined with 2 % of copper has been found to negate the deleterious effects of increased phosphor and molybdenum content. As a candidate steel at this stage, 14Cr-16Ni-0.013P-2Cu-1Al-(0.3-1)Mo steel has critical temperature of 110 ℃.

  8. Maintenance of dominance status is necessary for resistance to social defeat stress in Syrian hamsters.

    Science.gov (United States)

    Morrison, Kathleen E; Bader, Lauren R; Clinard, Catherine T; Gerhard, Danielle M; Gross, Sonya E; Cooper, Matthew A

    2014-08-15

    Resilience is an active process that involves a discrete set of neural substrates and cellular mechanisms and enables individuals to avoid some of the negative consequences of extreme stress. We have previously shown that dominant individuals show less stress-induced changes in behavior compared to subordinates using a conditioned defeat model in male Syrian hamsters (Mesocricetus auratus). To rule out pre-existing differences between dominants and subordinates, we examined whether 14 days of dominance experience is required to reduce the conditioned defeat response and whether the development of conditioned defeat resistance correlates with defeat-induced neural activation in select brain regions. We paired hamsters in daily 5-min aggressive encounters for 1, 7, or 14 days and then exposed animals to 3, 5-min social defeat episodes. The next day animals received conditioned defeat testing which involved a 5-min social interaction test with a non-aggressive intruder. In separate animals brains were collected after social defeat for c-Fos immunohistochemistry. We found that 14-day dominants showed a decreased conditioned defeat response compared to 14-day subordinates and controls, while 1-day and 7-day dominants did not differ from their subordinate counterparts. Also, the duration of dominance relationship was associated with distinct patterns of defeat-induced neural activation such that only 14-day dominants showed elevated c-Fos immunoreactivity in the ventral medial prefrontal cortex, medial amygdala, and lateral portions of the ventral medial hypothalamus. Our data suggest that resistance to social stress develops during the maintenance of dominance relationships and is associated with experience-dependent neural plasticity in select brain regions.

  9. Numerical design and optimization of hydraulic resistance and wall shear stress inside pressure-driven microfluidic networks.

    Science.gov (United States)

    Damiri, Hazem Salim; Bardaweel, Hamzeh Khalid

    2015-11-01

    Microfluidic networks represent the milestone of microfluidic devices. Recent advancements in microfluidic technologies mandate complex designs where both hydraulic resistance and pressure drop across the microfluidic network are minimized, while wall shear stress is precisely mapped throughout the network. In this work, a combination of theoretical and modeling techniques is used to construct a microfluidic network that operates under minimum hydraulic resistance and minimum pressure drop while constraining wall shear stress throughout the network. The results show that in order to minimize the hydraulic resistance and pressure drop throughout the network while maintaining constant wall shear stress throughout the network, geometric and shape conditions related to the compactness and aspect ratio of the parent and daughter branches must be followed. Also, results suggest that while a "local" minimum hydraulic resistance can be achieved for a geometry with an arbitrary aspect ratio, a "global" minimum hydraulic resistance occurs only when the aspect ratio of that geometry is set to unity. Thus, it is concluded that square and equilateral triangular cross-sectional area microfluidic networks have the least resistance compared to all rectangular and isosceles triangular cross-sectional microfluidic networks, respectively. Precise control over wall shear stress through the bifurcations of the microfluidic network is demonstrated in this work. Three multi-generation microfluidic network designs are considered. In these three designs, wall shear stress in the microfluidic network is successfully kept constant, increased in the daughter-branch direction, or decreased in the daughter-branch direction, respectively. For the multi-generation microfluidic network with constant wall shear stress, the design guidelines presented in this work result in identical profiles of wall shear stresses not only within a single generation but also through all the generations of the

  10. Numerical design and optimization of hydraulic resistance and wall shear stress inside pressure-driven microfluidic networks.

    Science.gov (United States)

    Damiri, Hazem Salim; Bardaweel, Hamzeh Khalid

    2015-11-01

    Microfluidic networks represent the milestone of microfluidic devices. Recent advancements in microfluidic technologies mandate complex designs where both hydraulic resistance and pressure drop across the microfluidic network are minimized, while wall shear stress is precisely mapped throughout the network. In this work, a combination of theoretical and modeling techniques is used to construct a microfluidic network that operates under minimum hydraulic resistance and minimum pressure drop while constraining wall shear stress throughout the network. The results show that in order to minimize the hydraulic resistance and pressure drop throughout the network while maintaining constant wall shear stress throughout the network, geometric and shape conditions related to the compactness and aspect ratio of the parent and daughter branches must be followed. Also, results suggest that while a "local" minimum hydraulic resistance can be achieved for a geometry with an arbitrary aspect ratio, a "global" minimum hydraulic resistance occurs only when the aspect ratio of that geometry is set to unity. Thus, it is concluded that square and equilateral triangular cross-sectional area microfluidic networks have the least resistance compared to all rectangular and isosceles triangular cross-sectional microfluidic networks, respectively. Precise control over wall shear stress through the bifurcations of the microfluidic network is demonstrated in this work. Three multi-generation microfluidic network designs are considered. In these three designs, wall shear stress in the microfluidic network is successfully kept constant, increased in the daughter-branch direction, or decreased in the daughter-branch direction, respectively. For the multi-generation microfluidic network with constant wall shear stress, the design guidelines presented in this work result in identical profiles of wall shear stresses not only within a single generation but also through all the generations of the

  11. In vitro selection for stress-resistant mutants and survey on offspring characteristics of peanut

    International Nuclear Information System (INIS)

    Previous studies in our lab had established high frequency of plant regeneration system via somatic embryogenesis and determination of the optimum mutation concentration of pingyangmycin (PYM), in vitro mutagenesis and directed screening for stress-resistant mutants of peanut were carried out in this study. The embryonic leaflets of peanut cv. Huayu 20 were cultured on induction medium supplemented with 3 mg/L PYM for 4 weeks to induce mutation. Hydroxyproline (HYP) was added to medium to provide selection pressure; the concentration was 4 mg/L for somatic embryo germination and 8 mg/L for plantlet formation. Regenerated mutant plants were transplanted to the field after graft and acclimation, 13 of them produced pods. The seeds of these 13 strains were sown in the field, 12 out of them exhibited different plant type compared with their wild type parent during seedling stage and growth stages, and most of them showed remarkable segregation of characters. The rest seeds from 7 of 13 strains mentioned above were sown in the green house, and were treated with drought stress. Most of the plants grew normally, while the wild type parent showed growth retardation. POD and SOD activity were determined using leaves subjected to drought stress as material. The results showed that the SOD values of 5 out of 7 lines were higher than that of the parent; the POD values of these lines also higher than that of the parent expect No.42. (authors)

  12. [Perception, processing of visual information and resistance to emotional stresses in athletes of different ages].

    Science.gov (United States)

    Korobeĭnikova, L H; Makarchuk, M Iu

    2013-01-01

    Among the numerous studies devoted to the study of perception and information processing, no data available on the effects of age on these processes. In this paper we studied the influence of psycho-emotional stress and different levels of stress on the mental processes of perception and information processing in highly skilled athletes divided into two groups. The first group included the athletes aged 19-24 years (12 athletes, members of the Ukrainian team in Greco-Roman wrestling), the second group included the athletes aged 27-31 years (7 highly skilled athletes, members of the Ukrainian team in Greco-Roman wrestling). We revealed that the athletes of the first group had higher productivity and better visual perception and visual information processing efficiency, compared with athletes from the second group. This observation suggests a dependency of cognitive component of perception and information processing on the age of the athletes. Sportsmen from the second group had higher stress resistance compared to the older age group.

  13. Nisin resistance of Listeria monocytogenes is increased by exposure to salt stress and is mediated via LiaR.

    Science.gov (United States)

    Bergholz, Teresa M; Tang, Silin; Wiedmann, Martin; Boor, Kathryn J

    2013-09-01

    Growth of Listeria monocytogenes on refrigerated, ready-to-eat food is a significant food safety concern. Natural antimicrobials, such as nisin, can be used to control this pathogen on food, but little is known about how other food-related stresses may impact how the pathogen responds to these compounds. Prior work demonstrated that exposure of L. monocytogenes to salt stress at 7°C led to increased expression of genes involved in nisin resistance, including the response regulator liaR. We hypothesized that exposure to salt stress would increase subsequent resistance to nisin and that LiaR would contribute to increased nisin resistance. Isogenic deletion mutations in liaR were constructed in 7 strains of L. monocytogenes, and strains were exposed to 6% NaCl in brain heart infusion broth and then tested for resistance to nisin (2 mg/ml Nisaplin) at 7°C. For the wild-type strains, exposure to salt significantly increased subsequent nisin resistance (P salt-induced nisin resistance of wild-type strains, ΔliaR strains were significantly more sensitive to nisin (P monocytogenes against subsequent inactivation by nisin. Transcript levels of LiaR-regulated genes were induced by salt stress, and lmo1746 and telA were found to contribute to LiaR-mediated salt-induced nisin resistance. These data suggest that environmental stresses similar to those on foods can influence the resistance of L. monocytogenes to antimicrobials such as nisin, and potential cross-protective effects should be considered when selecting and applying control measures for this pathogen on ready-to-eat foods. PMID:23851083

  14. Nisin resistance of Listeria monocytogenes is increased by exposure to salt stress and is mediated via LiaR.

    Science.gov (United States)

    Bergholz, Teresa M; Tang, Silin; Wiedmann, Martin; Boor, Kathryn J

    2013-09-01

    Growth of Listeria monocytogenes on refrigerated, ready-to-eat food is a significant food safety concern. Natural antimicrobials, such as nisin, can be used to control this pathogen on food, but little is known about how other food-related stresses may impact how the pathogen responds to these compounds. Prior work demonstrated that exposure of L. monocytogenes to salt stress at 7°C led to increased expression of genes involved in nisin resistance, including the response regulator liaR. We hypothesized that exposure to salt stress would increase subsequent resistance to nisin and that LiaR would contribute to increased nisin resistance. Isogenic deletion mutations in liaR were constructed in 7 strains of L. monocytogenes, and strains were exposed to 6% NaCl in brain heart infusion broth and then tested for resistance to nisin (2 mg/ml Nisaplin) at 7°C. For the wild-type strains, exposure to salt significantly increased subsequent nisin resistance (P nisin resistance of wild-type strains, ΔliaR strains were significantly more sensitive to nisin (P nisin. Transcript levels of LiaR-regulated genes were induced by salt stress, and lmo1746 and telA were found to contribute to LiaR-mediated salt-induced nisin resistance. These data suggest that environmental stresses similar to those on foods can influence the resistance of L. monocytogenes to antimicrobials such as nisin, and potential cross-protective effects should be considered when selecting and applying control measures for this pathogen on ready-to-eat foods.

  15. The influence of pretreatment with ghrelin on the development of acetic-acid-induced colitis in rats.

    Science.gov (United States)

    Maduzia, D; Matuszyk, A; Ceranowicz, D; Warzecha, Z; Ceranowicz, P; Fyderek, K; Galazka, K; Dembinski, A

    2015-12-01

    Ghrelin has been primarily shown to exhibit protective and therapeutic effect in the gut. Pretreatment with ghrelin inhibits the development of acute pancreatitis and accelerates pancreatic recovery in the course of this disease. In the stomach, ghrelin reduces gastric mucosal damage induced by ethanol, stress or alendronate, as well as accelerates the healing of acetic acid-induced gastric and duodenal ulcer. The aim of present studies was to investigate the effect of pretreatment with ghrelin on the development of acetic acid-induced colitis. Studies have been performed on male Wistar rats. Animals were treated intraperitoneally with saline (control) or ghrelin (4, 8 or 16 nmol/kg/dose). Saline or ghrelin was given twice: 8 and 1 h before induction of colitis. Colitis was induced by a rectal enema with 1 ml of 4% solution of acetic acid and the severity of colitis was assessed 1 or 24 hours after induction of inflammation. Rectal administration of acetic acid induced colitis in all animals. Damage of colonic wall was seen at the macroscopic and microscopic level. This effect was accompanied by a reduction in colonic blood flow and mucosal DNA synthesis. Moreover, induction of colitis significantly increased mucosal concentration of pro-inflammatory interleukin-1β (IL-1β), activity of myeloperoxidase and concentration of malondialdehyde (MDA). Mucosal activity of superoxide dismutase (SOD) was reduced. Pretreatment with ghrelin reduced the area and grade of mucosal damage. This effect was accompanied by an improvement of blood flow, DNA synthesis and SOD activity in colonic mucosa. Moreover, ghrelin administration reduced mucosal concentration of IL-1β and MDA, as well as decreased mucosal activity of myeloperoxidase. Administration of ghrelin protects the large bowel against the development of the acetic acid-induced colitis and this effect seems to be related to the ghrelin-evoked anti-inflammatory and anti-oxidative effects.

  16. Molecular pathways associated with stress resilience and drug resistance in the chronic mild stress rat model of depression: a gene expression study

    DEFF Research Database (Denmark)

    Bergström, Anders; Jayatissa, Magdalena Niepsuj; Andersen, Thomas Thykjær;

    2007-01-01

    The current antidepressant drugs are ineffective in 30 to 40% of the treated patients; hence, the pathophysiology of the disease needs to be further elucidated. We used the chronic mild stress (CMS) paradigm to induce anhedonia, a core symptom of major depression, in rats. A fraction of the animals...... exposed to CMS is resistant to the development of anhedonia; they are CMS resilient. In the CMS-sensitive animals, the induced anhedonic state is reversed in 50% of the animals when treating with escitalopram, whereas the remaining animals are treatment resistant. We used the microarray and the real...... a significant upregulation of apoptotic pathways in the treatment-resistant animals and significantly increased expression levels of genes involved in hippocampal signaling in the CMS-resilient rats. We hypothesize that sensitivity to the stress-induced anhedonia in rats is correlated with the impairment...

  17. Oxidative stress biomarker responses to an acute session of hypertrophy-resistance traditional interval training and circuit training.

    Science.gov (United States)

    Deminice, Rafael; Sicchieri, Tiago; Mialich, Mirele S; Milani, Francine; Ovidio, Paula P; Jordao, Alceu A

    2011-03-01

    We have studied circuit resistance schemes with high loads as a time-effective alternative to hypertrophy-traditional resistance training. However, the oxidative stress biomarker responses to high-load circuit training are unknown. The aim of the present study was to compare oxidative stress biomarker response with an acute session of hypertrophy-resistance circuit training and traditional interval training. A week after the 1 repetition maximum (1RM) test, 11 healthy and well-trained male participants completed hypertrophy-resistance acute sessions of traditional interval training (3 × 10 repetitions at 75% of the 1RM, with 90-second passive rest) and circuit training (3 × 10 repetitions at 75% of the 1RM, in alternating performance of 2 exercises with different muscle groups) in a randomized and cross-over design. Venous blood samples were collected before (pre) and 10 minutes after (post) the resistance training sessions for oxidative stress biomarker assays. As expected, the time used to complete the circuit training (20.2 ± 1.6) was half of that needed to complete the traditional interval training (40.3 ± 1.8). Significant increases (p < 0.05) in thiobarbituric acid reactive substances (40%), creatine kinase (CK) (67%), glutathione (14%), and uric acid (25%) were detected posttraditional interval training session in relation to pre. In relation to circuit training, a significant increase in CK (33%) activity postsession in relation to pre was observed. Statistical analysis did not reveal any other change in the oxidative stress biomarker after circuit training. In conclusion, circuit resistance-hypertrophy training scheme proposed in the current study promoted lower oxidative stress biomarkers and antioxidant modulations compared with resistance traditional interval training.

  18. Ecologically relevant stress resistance: from microarrays and quantitative trait loci to candidate genes – A research plan and preliminary results using Drosophila as a model organism and climatic and genetic stress as model stresses

    Indian Academy of Sciences (India)

    Volker Loeschcke; Jesper G Sørensen; Torsten N Kristensen

    2004-12-01

    We aim at studying adaptation to genetic and environmental stress and its evolutionary implications at different levels of biological organization. Stress influences cellular processes, individual physiology, genetic variation at the population level, and the process of natural selection. To investigate these highly connected levels of stress effects, it is advisable – if not critical – to integrate approaches from ecology, evolution, physiology, molecular biology and genetics. To investigate the mechanisms of stress resistance, how resistance evolves, and what factors contribute to and constrain its evolution, we use the well-defined model systems of Drosophila species, representing both cosmopolitan species such as D. melanogaster with a known genome map, and more specialized and ecologically well described species such as the cactophilic D. buzzatii. Various climate-related stresses are used as model stresses including desiccation, starvation, cold and heat. Genetic stress or genetic load is modelled by studying the consequences of inbreeding, the accumulation of (slightly) deleterious mutations, hybridization or the loss of genetic variability. We present here a research plan and preliminary results combining various approaches: molecular techniques such as microarrays, quantitative trait loci (QTL) analyses, quantitative PCR, ELISA or Western blotting are combined with population studies of resistance to climatic and genetic stress in natural populations collected across climatic gradients as well as in selection lines maintained in the laboratory.

  19. Prenatal SSRI alters the hormonal and behavioral responses to stress in female mice: Possible role for glucocorticoid resistance.

    Science.gov (United States)

    Avitsur, Ronit; Grinshpahet, Rachel; Goren, Naama; Weinstein, Ido; Kirshenboim, Or; Chlebowski, Noa

    2016-08-01

    Life time prevalence of major depression disorder (MDD) is higher in women compared to men especially during the period surrounding childbirth. Women suffering from MDD during pregnancy use antidepressant medications, particularly Selective Serotonin Reuptake Inhibitors (SSRI). These drugs readily cross the placental barrier and impact the developing fetal brain. The present study assessed the effects of prenatal exposure to fluoxetine (FLX), an SSRI antidepressant drug, on corticosterone and behavioral responses to stress in female mice. In young females, prenatal FLX significantly elevated corticosterone response to continuous stress. In adults, prenatal FLX augmented corticosterone response to acute stress and suppressed the response to continuous stress. Additionally, prenatal FLX significantly augmented stress-induced increase in locomotion and reduced anxiety- and depressive-like behaviors in adult, but not young mice. The dexamethasone suppression test revealed that prenatal FLX induced a state of glucocorticoid resistance in adult females, indicating that the negative feedback control of the hypothalamic-pituitary-adrenal axis response to stress was disrupted. These findings provide the first indication of altered hormonal and behavioral responses to continuous stress and suggest a role for the development of glucocorticoid resistance in these effects. According to these findings, prenatal environment may have implications for stress sensitivity and responsiveness to life challenges. Furthermore, this study may assist in understanding the limitations and precautions that should be taken in the use of SSRIs during pregnancy. PMID:27283378

  20. Bacteria associated with highly drought resistant Pistacia terebinthus: the key to reduce drought stress in other plant species?

    OpenAIRE

    Van de Weyer, Inge

    2013-01-01

    Plant-associated bacteria can not only stimulate plant growth, but also play an important role in the adaptation of their host plant to stress-inducing environmental conditions such as extreme drought. In this project, the effect of inoculation with selected endophytic bacteria isolated from the highly drought resistant tree Pistacia terebinthus on the drought resistance of four different plant species was evaluated. The results show that drought had a strong negative impact on all plant spec...

  1. Influence of Two Various Durations of Resistance Exercise on Oxidative Stress in the Male Rat’s Hearts

    OpenAIRE

    Rafigheh Ghiasi; Mustafa Mohammadi; Javad Ashrafi Helan; Seied Razi Jafari Jozani; Shima Mohammadi; Akbar Ghiasi; Roya Naderi

    2015-01-01

    Introduction: The previous studies have suggested that alteration in oxidative stress and antioxidant defense depends on various factors, such as mode, intensity, frequency and duration of exercise. In this study, we compared the effects of two various durations of resistance exercise (1 month and 4 month) on oxidative stress and antioxidant status in cardiac tissue. Methods: Thirty Wistar male rats divided into 3 groups: control (sedentary), exercise-1 (regular exercise for 1 month) and exer...

  2. Life at the Limits: Capacities of Isolated and Cultured Lichen Symbionts to Resist Extreme Environmental Stresses

    Science.gov (United States)

    de Vera, J.-P.; Rettberg, P.; Ott, S.

    2008-10-01

    Lichens are described as a symbiosis formed by a myco- and photobiont, capable of colonizing habitats where their separate symbionts would not be able to survive. Space simulation studies on the separated symbionts of the lichen Xanthoria elegans have been performed to test their capacity to resist the most extreme conditions. The isolated cultured symbiont cells were exposed to different doses of the UV spectrum, and to vacuum. Cultures of both symbionts were analysed by specific vitality tests (LIVE/DEAD-staining detected by Confocal Laser Scanning Microscopy). Growth capacity of symbiont cultures on different media was analysed after exposure to extreme environmental stresses. The data obtained support the hypothesis that the symbiotic state considerably enhances the ability of the respective symbionts to survive exposure to extreme conditions, including the conditions of space simulation. Species such as X. elegans may, therefore, be suitable for use as model organisms in exobiological studies.

  3. Mechanical properties and environmental stress cracking resistance of rubber toughened polyester/kenaf composite

    Directory of Open Access Journals (Sweden)

    2010-02-01

    Full Text Available In this study rubber-toughened polyester-kenaf fibre composites were prepared by adding various percentages of kenaf fibre in unsaturated polyester resin and subsequently cross linked using a mixture of organic peroxide methyl ethyl ketone and cobalt octanoate. Three percent (3% of liquid natural rubber (LNR were added as a toughening agent. The mechanical properties of the composites were evaluated by impact and flexural testing. Environmental stress cracking resistance (ESCR of polyester-kenaf composite in acid and base medium was also studied. It was found that the addition of LNR increased impact strength by about 66% and flexural strength by 70%. Measurement of ESCR shows that the composite has the fastest diffusion rate in acid medium, followed by that in base medium and then without medium. Bonding mechanisms were assessed by scanning electron microscope and FTIR analysis.

  4. Association and Heritability Studies for Drought Resistance under Varied Moisture Stress Regimes in Backcross Inbred Population of Rice

    Institute of Scientific and Technical Information of China (English)

    R SELLAMMAL; S ROBIN; M RAVEENDRAN

    2014-01-01

    Drought stress is one of the major constraints affecting rice production and yield stability in the rainfed regions. To understand the physiological basis of drought resistance related component traits, we used a backcross inbred population of rice under three kinds of moisture regimes viz., non-stress, moderate (24.48%) and severe stress (73.97%) conditions which reflect the differential responses of the genotypes to varying stress intensities. The plot yield, 1000-grain weight, panicle exsertion and canopy air temperature difference exhibited high heritability under the control conditions, whereas spikelet sterility and single plant yield exhibited high heritability under the moderate stress conditions. Traits such as days to 50% flowering, plant height and osmotic potential showed high heritability under the severe stress conditions. Plot yield under stress was significantly and positively correlated with harvest index and 1000-grain weight, but negatively associated with leaf rolling score and days to 50% flowering. The drought susceptibility index and drought response index were negatively correlated between each other both under the moderate and severe stress conditions. The derived traits viz., difference in panicle length between the control and the severe stress was associated with osmotic adjustment measured under field conditions. Difference in plant height and panicle length was negatively associated with plot yield under stress.

  5. The mechanism of heterogeneous beta-lactam resistance in MRSA: key role of the stringent stress response.

    Directory of Open Access Journals (Sweden)

    Choonkeun Kim

    Full Text Available All methicillin resistant S. aureus (MRSA strains carry an acquired genetic determinant--mecA or mecC--which encode for a low affinity penicillin binding protein -PBP2A or PBP2A'--that can continue the catalysis of peptidoglycan transpeptidation in the presence of high concentrations of beta-lactam antibiotics which would inhibit the native PBPs normally involved with the synthesis of staphylococcal cell wall peptidoglycan. In contrast to this common genetic and biochemical mechanism carried by all MRSA strains, the level of beta-lactam antibiotic resistance shows a very wide strain to strain variation, the mechanism of which has remained poorly understood. The overwhelming majority of MRSA strains produce a unique--heterogeneous--phenotype in which the great majority of the bacteria exhibit very poor resistance often close to the MIC value of susceptible S. aureus strains. However, cultures of such heterogeneously resistant MRSA strains also contain subpopulations of bacteria with extremely high beta-lactam MIC values and the resistance level and frequency of the highly resistant cells in such strain is a characteristic of the particular MRSA clone. In the study described in this communication, we used a variety of experimental models to understand the mechanism of heterogeneous beta-lactam resistance. Methicillin-susceptible S. aureus (MSSA that received the mecA determinant in the laboratory either on a plasmid or in the form of a chromosomal SCCmec cassette, generated heterogeneously resistant cultures and the highly resistant subpopulations that emerged in these models had increased levels of PBP2A and were composed of bacteria in which the stringent stress response was induced. Each of the major heterogeneously resistant clones of MRSA clinical isolates could be converted to express high level and homogeneous resistance if the growth medium contained an inducer of the stringent stress response.

  6. A Novel Peptide from Soybean Protein Isolate Significantly Enhances Resistance of the Organism under Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Heran Ma

    Full Text Available Recent studies have indicated that protein hydrolysates have broad biological effects. In the current study we describe a novel antioxidative peptide, FDPAL, from soybean protein isolate (SPI. The aim of this study was to purify and characterize an antioxidative peptide from SPI and determine its antioxidative mechanism. LC-MS/MS was used to isolate and identify the peptide from SPI. The sequence of the peptide was determined to be Phe-Asp-Pro-Ala-Leu (FDPAL, 561 Da. FDPAL can cause significant enhancement of resistance to oxidative stress both in cells as well as simple organisms. In Caenorhabditis elegans (C. elegans, FDPAL can up-regulate the expression of certain genes associated with resistance. The antioxidant activity of this peptide can be attributed to the presence of a specific amino acid sequence. Results from our work suggest that FDPAL can facilitate potential applications of proteins carrying this sequence in the nutraceutical, bioactive material and clinical medicine areas, as well as in cosmetics and health care products.

  7. Breeding of lager yeast with Saccharomyces cerevisiae improves stress resistance and fermentation performance.

    Science.gov (United States)

    Garcia Sanchez, Rosa; Solodovnikova, Natalia; Wendland, Jürgen

    2012-08-01

    Lager beer brewing relies on strains collectively known as Saccharomyces carlsbergensis, which are hybrids between S. cerevisiae and S. eubayanus-like strains. Lager yeasts are particularly adapted to low-temperature fermentations. Selection of new yeast strains for improved traits or fermentation performance is laborious, due to the allotetraploid nature of lager yeasts. Initially, we have generated new F1 hybrids by classical genetics, using spore clones of lager yeast and S. cerevisiae and complementation of auxotrophies of the single strains upon mating. These hybrids were improved on several parameters, including growth at elevated temperature and resistance against high osmolarity or high ethanol concentrations. Due to the uncertainty of chromosomal make-up of lager yeast spore clones, we introduced molecular markers to analyse mating-type composition by PCR. Based on these results, new hybrids between a lager and an ale yeast strain were isolated by micromanipulation. These hybrids were not subject to genetic modification. We generated and verified 13 hybrid strains. All of these hybrid strains showed improved stress resistance as seen in the ale parent, including improved survival at the end of fermentation. Importantly, some of the strains showed improved fermentation rates using 18° Plato at 18-25°C. Uniparental mitochondrial DNA inheritance was observed mostly from the S. cerevisiae parent.

  8. fungal disease resistance in vicia faba in relation to water stress and gamma irradiation

    International Nuclear Information System (INIS)

    Induced systemic resistance (Isr), as a recent strategy, achieving biological control of plant disease through initiation to form natural antibiotic compounds, phytoalexin, that considered to be involved in the defense mechanism of plant to potential pathogen. Also, phytoalexin formed by leguminosae in response to infection play an extremely role in disease resistance. Indeed, wyerone acid (C14H12O4) has been clearfield as a phytoalexin formed by Vicia faba in response to infection stress. Therefore, the present study was outlined to clearify the feasibility to biocontrol of checolate spot disease caused by Botrytis fabae in faba bean, Vicia faba, plants under field condition. Pre. Sowing seed irradiated with low gamma ray were planted in: 1- Three pot experiments (salinity-Ni-Si) in complete randomized block design in three replicates. 2- Two field experiments in loam soil irrigated with river nile water (inducers-Isr)) in splite-plot design in three replicates. 3- Two field experiments in sandy soil irrigated with two saline water from 2 shallow-wells (inducers-Isr) in split-split plot design in three replicates

  9. Metallurgical and mechanical parameters controlling alloy 718 stress corrosion cracking resistance in PWR primary water

    International Nuclear Information System (INIS)

    Improving the performance and reliability of the fuel assemblies of the pressurized water reactors requires having a perfect knowledge of the operating margins of both the components and the materials. The choice of alloy 718 as reference material for this study is justified by the industrial will to identify the first order parameters controlling the excellent resistance of this alloy to Stress Corrosion Cracking (SCC). For this purpose, a specific slow strain rate (SSR) crack initiation test using tensile specimen with a V-shaped hump in the middle of the gauge length was developed and modeled. The selectivity of such SSR tests in simulated PWR primary water at 350 C was clearly established by characterizing the SCC resistance of nine alloy 718 thin strip heats. Regardless of their origin and in spite of a similar thermo-mechanical history, they did not exhibit the same susceptibility to SCC crack initiation. All the characterized alloy 718 heats develop oxide scale of similar nature for various exposure times to PWR primary medium in the temperature range [320 C - 360 C]. δ phase precipitation has no impact on alloy 718 SCC initiation behavior when exposed to PWR primary water, contrary to interstitial contents and the triggering of plastic instabilities (PLC phenomenon). (author)

  10. Plant resistance to cold stress: Mechanisms and environmental signals triggering frost hardening and dehardening

    Indian Academy of Sciences (India)

    Erwin H Beck; Richard Heim; Jens Hansen

    2004-12-01

    This introductory overview shows that cold, in particular frost, stresses a plant in manifold ways and that the plant’s response, being injurious or adaptive, must be considered a syndrome rather than a single reaction. In the course of the year perennial plants of the temperate climate zones undergo frost hardening in autumn and dehardening in spring. Using Scots pine (Pinus sylvestris L.) as a model plant the environmental signals inducing frost hardening and dehardening, respectively, were investigated. Over 2 years the changes in frost resistance of Scots pine needles were recorded together with the annual courses of day-length and ambient temperature. Both act as environmental signals for frost hardening and dehardening. Climate chamber experiments showed that short day-length as a signal triggering frost hardening could be replaced by irradiation with far red light, while red light inhibited hardening. The involvement of phytochrome as a signal receptor could be corroborated by respective night-break experiments. More rapid frost hardening than by short day or far red treatment was achieved by applying a short period (6 h) of mild frost which did not exceed the plant’s cold resistance. Both types of signals were independently effective but the rates of frost hardening were not additive. The maximal rate of hardening was – 0.93°C per day and frost tolerance of < – 72°C was achieved. For dehardening, temperature was an even more effective signal than day-length.

  11. Overexpression of a Drosophila homolog of apolipoprotein D leads to increased stress resistance and extended lifespan.

    Science.gov (United States)

    Walker, David W; Muffat, Julien; Rundel, Colin; Benzer, Seymour

    2006-04-01

    Increased Apolipoprotein D (ApoD) expression has been reported in various neurological disorders, including Alzheimer's disease, schizophrenia, and stroke, and in the aging brain . However, whether ApoD is toxic or a defense is unknown. In a screen to identify genes that protect Drosophila against acute oxidative stress, we isolated a fly homolog of ApoD, Glial Lazarillo (GLaz). In independent transgenic lines, overexpression of GLaz resulted in increased resistance to hyperoxia (100% O(2)) as well as a 29% extension of lifespan under normoxia. These flies also displayed marked improvements in climbing and walking ability after sublethal exposure to hyperoxia. Overexpression of Glaz also increased resistance to starvation without altering lipid or protein content. To determine whether GLaz might be important in protection against reperfusion injury, we subjected the flies to hypoxia, followed by recovery under normoxia. Overexpression of GLaz was protective against behavioral deficits caused in normal flies by this ischemia/reperfusion paradigm. This and the accompanying paper by Sanchez et al. (in this issue of Current Biology) are the first to manipulate the levels of an ApoD homolog in a model organism. Our data suggest that human ApoD may play a protective role and thus may constitute a therapeutic target to counteract certain neurological diseases.

  12. A Novel Peptide from Soybean Protein Isolate Significantly Enhances Resistance of the Organism under Oxidative Stress.

    Science.gov (United States)

    Ma, Heran; Liu, Rui; Zhao, Ziyuan; Zhang, Zhixian; Cao, Yue; Ma, Yudan; Guo, Yi; Xu, Li

    2016-01-01

    Recent studies have indicated that protein hydrolysates have broad biological effects. In the current study we describe a novel antioxidative peptide, FDPAL, from soybean protein isolate (SPI). The aim of this study was to purify and characterize an antioxidative peptide from SPI and determine its antioxidative mechanism. LC-MS/MS was used to isolate and identify the peptide from SPI. The sequence of the peptide was determined to be Phe-Asp-Pro-Ala-Leu (FDPAL, 561 Da). FDPAL can cause significant enhancement of resistance to oxidative stress both in cells as well as simple organisms. In Caenorhabditis elegans (C. elegans), FDPAL can up-regulate the expression of certain genes associated with resistance. The antioxidant activity of this peptide can be attributed to the presence of a specific amino acid sequence. Results from our work suggest that FDPAL can facilitate potential applications of proteins carrying this sequence in the nutraceutical, bioactive material and clinical medicine areas, as well as in cosmetics and health care products. PMID:27455060

  13. [Enhanced Resistance of Pea Plants to Oxidative: Stress Caused by Paraquat during Colonization by Aerobic Methylobacteria].

    Science.gov (United States)

    Agafonova, N V; Doronina, N Y; Trotsenko, Yu A

    2016-01-01

    The influence of colonization of the pea (Pisum sativum L.) by aerobic methylobacteria of five different species (Methylophilus flavus Ship, Methylobacterium extorquens G10, Methylobacillus arboreus Iva, Methylopila musalis MUSA, Methylopila turkiensis Sidel) on plant resistance to paraquat-induced stresses has been studied. The normal conditions of pea colonization by methylobacteria were characterized by a decrease in the activity of antioxidant enzymes (superoxide dismutase, catalase, and peroxidases) and in the concentrations of endogenous H2O2, proline, and malonic dialdehyde, which is a product of lipid peroxidation and indicator of damage to plant cell membranes, and an increase in the activity of the photosynthetic apparatus (the content of chlorophylls a, b and carotenoids). In the presence of paraquat, the colonized plants had higher activities of antioxidant enzymes, stable photosynthetic indices, and a less intensive accumulation of the products of lipid peroxidation as compared to noncolonized plants. Thus, colonization by methylobacteria considerably increased the adaptive protection of pea plants to the paraquat-induced oxidative stress.

  14. Insulin Resistance in PCOS Patients Enhances Oxidative Stress and Leukocyte Adhesion: Role of Myeloperoxidase.

    Science.gov (United States)

    Victor, Victor M; Rovira-Llopis, Susana; Bañuls, Celia; Diaz-Morales, Noelia; Martinez de Marañon, Arantxa; Rios-Navarro, Cesar; Alvarez, Angeles; Gomez, Marcelino; Rocha, Milagros; Hernández-Mijares, Antonio

    2016-01-01

    Cardiovascular diseases and oxidative stress are related to polycystic ovary syndrome (PCOS) and insulin resistance (IR). We have evaluated the relationship between myeloperoxidase (MPO) and leukocyte activation in PCOS patients according to homeostatic model assessment of IR (HOMA-IR), and have explored a possible correlation between these factors and endocrine and inflammatory parameters. This was a prospective controlled study conducted in an academic medical center. The study population consisted of 101 PCOS subjects and 105 control subjects. We divided PCOS subjects into PCOS non-IR (HOMA-IRPCOS IR (HOMA-IR>2.5). Metabolic and anthropometric parameters, total and mitochondrial reactive oxygen species (ROS) production, MPO levels, interactions between human umbilical vein endothelial cells and leukocytes, adhesion molecules (E-selectin, ICAM-1 and VCAM-1) and proinflammatory cytokines (IL-6 and TNF-α) were evaluated. Oxidative stress was observed in PCOS patients, in whom there was an increase in total and mitochondrial ROS production and MPO levels. Enhanced rolling flux and adhesion, and a decrease in polymorphonuclear cell rolling velocity were also detected in PCOS subjects. Increases in IL-6 and TNF-α and adhesion molecules (E-selectin, ICAM-1 and VCAM-1) were also observed, particularly in the PCOS IR group, providing evidence that inflammation and oxidative stress are related in PCOS patients. HOMA-IR was positively correlated with hsCRP (pPCOS patients in general, and particularly in those with IR. Inflammation in PCOS induces leukocyte-endothelium interactions and a simultaneous increase in IL-6, TNF-α, E-selectin, ICAM-1 and VCAM-1. These conditions are aggravated by the presence of IR.

  15. Loss of glial lazarillo, a homolog of apolipoprotein D, reduces lifespan and stress resistance in Drosophila.

    Science.gov (United States)

    Sanchez, Diego; López-Arias, Begoña; Torroja, Laura; Canal, Inmaculada; Wang, Xiaohui; Bastiani, Michael J; Ganfornina, Maria D

    2006-04-01

    The vertebrate Apolipoprotein D (ApoD) is a lipocalin secreted from subsets of neurons and glia during neural development and aging . A strong correlation exists between ApoD overexpression and numerous nervous system pathologies as well as obesity, diabetes, and many forms of cancer . However, the exact relationship between the function of ApoD and the pathophysiology of these diseases is still unknown. We have generated loss-of-function Drosophila mutants for the Glial Lazarillo (GLaz) gene , a homolog of ApoD in the fruit fly, mainly expressed in subsets of adult glial cells. The absence of GLaz reduces the organism's resistance to oxidative stress and starvation and shortens male lifespan. The mutant flies exhibit a smaller body mass due to a lower amount of neutral lipids stored in the fat body. Apoptotic neural cell death increases in aged flies or upon paraquat treatment, which also impairs neural function as assessed by behavioral tests. The higher sensitivity to oxidative stress and starvation and the reduced fat storage revert to control levels when a GFP-GLaz fusion protein is expressed under the control of the GLaz natural promoter. Finally, GLaz mutants have a higher concentration of lipid peroxidation products, pointing to a lipid peroxidation protection or scavenging as the mechanism of action for this lipocalin. In agreement with Walker et al. (, in this issue of Current Biology), who analyze the effects of overexpressing GLaz, we conclude that GLaz has a protective role in stress situations and that its absence reduces lifespan and accelerates neurodegeneration.

  16. Induction of multixenobiotic defense mechanisms in resistant Daphnia magna clones as a general cellular response to stress.

    Science.gov (United States)

    Jordão, Rita; Campos, Bruno; Lemos, Marco F L; Soares, Amadeu M V M; Tauler, Romà; Barata, Carlos

    2016-06-01

    Multixenobiotic resistance mechanisms (MXR) were recently identified in Daphnia magna. Previous results characterized gene transcripts of genes encoding and efflux activities of four putative ABCB1 and ABCC transporters that were chemically induced but showed low specificity against model transporter substrates and inhibitors, thus preventing us from distinguishing between activities of different efflux transporter types. In this study we report on the specificity of induction of ABC transporters and of the stress protein hsp70 in clones selected to be genetically resistant to ABCB1 chemical substrates. Clones resistant to mitoxantrone, ivermectin and pentachlorophenol showed distinctive transcriptional responses of transporter protein coding genes and of putative transporter dye activities. Expression of hsp70 proteins also varied across resistant clones. Clones resistant to mitoxantrone and pentachlorophenol showed high constitutive levels of hsp70. Transcriptional levels of the abcb1 gene transporter and of putative dye transporter activity were also induced to a greater extent in the pentachlorophenol resistant clone. Observed higher dye transporter activities in individuals from clones resistant to mitoxantrone and ivermectin were unrelated with transcriptional levels of the studied four abcc and abcb1 transporter genes. These findings suggest that Abcb1 induction in D. magna may be a part of a general cellular stress response. PMID:27039215

  17. ZmNAC55, a maize stress-responsive NAC transcription factor, confers drought resistance in transgenic Arabidopsis.

    Science.gov (United States)

    Mao, Hude; Yu, Lijuan; Han, Ran; Li, Zhanjie; Liu, Hui

    2016-08-01

    Abiotic stress has been shown to significantly limit the growth and productivity of crops. NAC transcription factors play essential roles in response to various abiotic stresses. However, only little information regarding stress-related NAC genes is available in maize. Here, we cloned a maize NAC transcription factor ZmNAC55 and identified its function in drought stress. Transient expression and transactivation assay demonstrated that ZmNAC55 was localized in the nucleus and had transactivation activity. Expression analysis of ZmNAC55 in maize showed that this gene was induced by drought, high salinity and cold stresses and by abscisic acid (ABA). Promoter analysis demonstrated that multiple stress-related cis-acting elements exist in promoter region of ZmNAC55. Overexpression of ZmNAC55 in Arabidopsis led to hypersensitivity to ABA at the germination stage, but enhanced drought resistence compared to wild-type seedlings. Transcriptome analysis identified a number of differentially expressed genes between 35S::ZmNAC55 transgenic and wild-type plants, and many of which are involved in stress response, including twelve qRT-PCR confirmed well-known drought-responsive genes. These results highlight the important role of ZmNAC55 in positive regulates of drought resistence, and may have potential applications in transgenic breeding of drought-tolerant crops. PMID:27085597

  18. Systematic identification of genes involved in metabolic acid stress resistance in yeast and their potential as cancer targets

    Directory of Open Access Journals (Sweden)

    John J. Shin

    2016-09-01

    Full Text Available A hallmark of all primary and metastatic tumours is their high rate of glucose uptake and glycolysis. A consequence of the glycolytic phenotype is the accumulation of metabolic acid; hence, tumour cells experience considerable intracellular acid stress. To compensate, tumour cells upregulate acid pumps, which expel the metabolic acid into the surrounding tumour environment, resulting in alkalization of intracellular pH and acidification of the tumour microenvironment. Nevertheless, we have only a limited understanding of the consequences of altered intracellular pH on cell physiology, or of the genes and pathways that respond to metabolic acid stress. We have used yeast as a genetic model for metabolic acid stress with the rationale that the metabolic changes that occur in cancer that lead to intracellular acid stress are likely fundamental. Using a quantitative systems biology approach we identified 129 genes required for optimal growth under conditions of metabolic acid stress. We identified six highly conserved protein complexes with functions related to oxidative phosphorylation (mitochondrial respiratory chain complex III and IV, mitochondrial tRNA biosynthesis [glutamyl-tRNA(Gln amidotransferase complex], histone methylation (Set1C–COMPASS, lysosome biogenesis (AP-3 adapter complex, and mRNA processing and P-body formation (PAN complex. We tested roles for two of these, AP-3 adapter complex and PAN deadenylase complex, in resistance to acid stress using a myeloid leukaemia-derived human cell line that we determined to be acid stress resistant. Loss of either complex inhibited growth of Hap1 cells at neutral pH and caused sensitivity to acid stress, indicating that AP-3 and PAN complexes are promising new targets in the treatment of cancer. Additionally, our data suggests that tumours may be genetically sensitized to acid stress and hence susceptible to acid stress-directed therapies, as many tumours accumulate mutations in mitochondrial

  19. Systematic identification of genes involved in metabolic acid stress resistance in yeast and their potential as cancer targets.

    Science.gov (United States)

    Shin, John J; Aftab, Qurratulain; Austin, Pamela; McQueen, Jennifer A; Poon, Tak; Li, Shu Chen; Young, Barry P; Roskelley, Calvin D; Loewen, Christopher J R

    2016-09-01

    A hallmark of all primary and metastatic tumours is their high rate of glucose uptake and glycolysis. A consequence of the glycolytic phenotype is the accumulation of metabolic acid; hence, tumour cells experience considerable intracellular acid stress. To compensate, tumour cells upregulate acid pumps, which expel the metabolic acid into the surrounding tumour environment, resulting in alkalization of intracellular pH and acidification of the tumour microenvironment. Nevertheless, we have only a limited understanding of the consequences of altered intracellular pH on cell physiology, or of the genes and pathways that respond to metabolic acid stress. We have used yeast as a genetic model for metabolic acid stress with the rationale that the metabolic changes that occur in cancer that lead to intracellular acid stress are likely fundamental. Using a quantitative systems biology approach we identified 129 genes required for optimal growth under conditions of metabolic acid stress. We identified six highly conserved protein complexes with functions related to oxidative phosphorylation (mitochondrial respiratory chain complex III and IV), mitochondrial tRNA biosynthesis [glutamyl-tRNA(Gln) amidotransferase complex], histone methylation (Set1C-COMPASS), lysosome biogenesis (AP-3 adapter complex), and mRNA processing and P-body formation (PAN complex). We tested roles for two of these, AP-3 adapter complex and PAN deadenylase complex, in resistance to acid stress using a myeloid leukaemia-derived human cell line that we determined to be acid stress resistant. Loss of either complex inhibited growth of Hap1 cells at neutral pH and caused sensitivity to acid stress, indicating that AP-3 and PAN complexes are promising new targets in the treatment of cancer. Additionally, our data suggests that tumours may be genetically sensitized to acid stress and hence susceptible to acid stress-directed therapies, as many tumours accumulate mutations in mitochondrial respiratory chain

  20. Cortisol Response to a Crowding Stress: Heritability and Association with Disease Resistance to Yersinia ruckeri in Rainbow Trout

    Science.gov (United States)

    A breeding program to develop improved germplasm for the US rainbow trout aquaculture industry is being conducted at the USDA-ARS National Center for Cool and Cold Water Aquaculture. Current selection efforts are focused on growth and disease resistance, but stress response is also a concern. Usin...

  1. Oxidative stress responses to a graded maximal exercise test in older adults following explosive-type resistance training

    DEFF Research Database (Denmark)

    Ceci, R.; Beltran Valls, M.R.; Duranti, G.;

    2014-01-01

    We recently demonstrated that low frequency, moderate intensity, explosive-type resistance training (EMRT) is highly beneficial in elderly subjects towards muscle strength and power, with a systemic adaptive response of anti-oxidant and stress-induced markers. In the present study, we aimed to ev...

  2. A peroxiredoxin, PRDX-2, is required for insulin secretion and insulin/IIS-dependent regulation of stress resistance and longevity.

    Science.gov (United States)

    Oláhová, Monika; Veal, Elizabeth A

    2015-08-01

    Peroxiredoxins (Prx) are abundant thiol peroxidases with a conserved anti-ageing role. In contrast to most animals, the nematode worm, Caenorhabditis elegans, encodes a single cytosolic 2-Cys Prx, PRDX-2, rendering it an excellent model for examining how peroxiredoxins affect animal physiology and ageing. Our previous work revealed that, although PRDX-2 protects against the toxicity of peroxides, enigmatically, prdx-2-mutant animals are hyper-resistant to other forms of oxidative stress. Here, we have investigated the basis for this increased resistance. Mammalian FOXO and Nrf2 transcription factors directly promote the expression of a range of detoxification enzymes. We show that the FOXO orthologue, DAF-16, and the Nrf2 orthologue, SKN-1, are required for the increased stress resistance of prdx-2-mutant worms. Our data suggest that PRDX-2 is required for normal levels of insulin secretion and hence the inhibition of DAF-16 and SKN-1 by insulin/IGF-1-like signalling (IIS) under nutrient-rich conditions. Intriguingly, loss of PRDX-2 increases DAF-16 and SKN-1 activities sufficiently to increase arsenite resistance without initiating other IIS-inhibited processes. Together, these data suggest that loss of peroxiredoxin function may increase stress resistance by reducing insulin secretion, but that further changes in insulin signalling are required for the reprogramming of development and fat metabolism. In addition, we reveal that the temperature-dependent prolongevity function of PRDX-2 is required for the extended lifespan associated with several pathways, including further reductions in IIS. PMID:25808059

  3. Green Synthesis of Oxovanadium(IV)/chitosan Nanocomposites and Its Ameliorative Effect on Hyperglycemia, Insulin Resistance, and Oxidative Stress.

    Science.gov (United States)

    Liu, Yanjun; Jie, Xu; Guo, Yongli; Zhang, Xin; Wang, Jingfeng; Xue, Changhu

    2016-02-01

    In this paper, the preparation, characterization, and ameliorative effect on high-fat high-sucrose diet-induced hyperglycemia, insulin resistance, oxidative stress in mice of novel oxovanadium(IV)/chitosan (OV/CS) nanocomposites were investigated. The nanobiocomposite was produced by chemical reduction by chitosan and L-ascorbic acid using microwave heating, under environment-friendly conditions, using aqueous solutions, and notably, by using both mediators as reducing and stabilizing agents. In addition, OV/CS nanocomposites were characterized by transmission electron microscopy, energy dispersive spectroscopy, particle size, and zeta potential measurements. In vivo experiments were designed to examine whether the OV/CS nanocomposites would provide additional benefits on oxidative stress, hyperglycemia, and insulin resistance in mice with type 2 diabetes. The results rendered insulin resistant by treating with OV/CS nanocomposites alleviate insulin resistance and improve oxidative stress. Such nanocomposite seem to be a valuable therapy to achieve and/or maintain glycemic control and therapeutic agents in the treatment arsenal for insulin resistance and type 2 diabetes. PMID:26144273

  4. Differential gene expression profiling of Listeria monocytogenes in Cacciatore and Felino salami to reveal potential stress resistance biomarkers.

    Science.gov (United States)

    Mataragas, M; Rovetto, F; Bellio, A; Alessandria, V; Rantsiou, K; Decastelli, L; Cocolin, L

    2015-04-01

    The current study reports a) the in situ transcriptional profiles of Listeria monocytogenes in response to fermented sausage stress and b) an approach in which in situ RT-qPCR data have been combined with advanced statistical techniques to discover potential stress resistance or cell viability biomarkers. Gene expression profiling of the pathogen has been investigated using RT-qPCR to understand how L. monocytogenes responds to the conditions encountered during the fermentation and ripening of sausages. A cocktail of five L. monocytogenes strains was inoculated into the batter of Cacciatore and Felino sausages. The RT-qPCR data showed that the acidic and osmotic stress-related genes were up-regulated. The transcripts of the lmo0669 gene increased during the fermentation and ripening of Cacciatore, whereas gbuA and lmo1421 were up-regulated during the ripening of Felino and Cacciatore, respectively. sigB expression was induced in both sausages throughout the whole process. Finally, the virulence-related gene prfA was down-regulated during the fermentation of Cacciatore. The multivariate gene expression profiling analysis suggested that sigB and lmo1421 or sigB and gbuA could be used as different types of stress resistance biomarkers to track, for example, stress resistance or cell viability in fermented sausages with short (Cacciatore) or long (Felino) maturation times, respectively. PMID:25475310

  5. Overexpression of an ABA biosynthesis gene using a stress-inducible promoter enhances drought resistance in petunia.

    Science.gov (United States)

    Estrada-Melo, Alejandro C; Chao; Reid, Michael S; Jiang, Cai-Zhong

    2015-01-01

    The response of plants to drought stress includes reduced transpiration as stomates close in response to increased abscisic acid (ABA) concentrations. Constitutive overexpression of 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in ABA biosynthesis, increases drought resistance, but causes negative pleiotropic effects on plant growth and development. We overexpressed the tomato NCED (LeNCED1) in petunia plants under the control of a stress-inducible promoter, rd29A. Under water stress, the transgenic plants had increased transcripts of NCED mRNA, elevated leaf ABA concentrations, increased concentrations of proline, and a significant increase in drought resistance. The transgenic plants also displayed the expected decreases in stomatal conductance, transpiration, and photosynthesis. After 14 days without water, the control plants were dead, but the transgenic plants, though wilted, recovered fully when re-watered. Well-watered transgenic plants grew like non-transformed control plants and there was no effect of the transgene on seed dormancy. PMID:26504568

  6. Induction of a stress response in Lactococcus lactis is associated with a resistance to ribosomally active antibiotics.

    Science.gov (United States)

    Dorrian, James M; Briggs, Deborah A; Ridley, Michael L; Layfield, Robert; Kerr, Ian D

    2011-11-01

    The acquisition of multidrug resistance in bacteria underlies the failure of antimicrobial therapy, and the emergence of pathogens that are resistant to almost the entire armoury of antibiotics. Among the proteins that can mediate or contribute to the drug-resistance profile in Gram-positive bacteria is a subset of ATP-binding cassette proteins that are comprised of a tandem-repeated nucleotide-binding domain. In this study, we expressed one of these NBD(2) proteins, LmrC, in an antibiotic-sensitive Gram-positive host strain (Lactococcus lactis) and demonstrated the acquisition of resistance to ribosomally active antibiotics. Mutation of key catalytic residues suggested that the resistance profile was the result of a cellular response, rather than being a function of the NBD(2) protein itself. This observation was confirmed by 2D SDS/PAGE, which demonstrated that the expression of the NBD(2) protein induced a stress response in L. lactis. A model combining this stress response induction and the acquisition of antibiotic resistance is proposed. PMID:21848804

  7. The overexpression of an Amaranthus hypochondriacus NF-YC gene modifies growth and confers water deficit stress resistance in Arabidopsis.

    Science.gov (United States)

    Palmeros-Suárez, Paola A; Massange-Sánchez, Julio A; Martínez-Gallardo, Norma A; Montero-Vargas, Josaphat M; Gómez-Leyva, Juan F; Délano-Frier, John P

    2015-11-01

    Nuclear factor-Y (NF-Y), is a plant heterotrimeric transcription factor constituted by NF-YA, NF-YB and NF-YC subunits. The function of many NF-Y subunits, mostly of the A and B type, has been studied in plants, but knowledge regarding the C subunit remains fragmentary. Here, a water stress-induced NF-YC gene from Amaranthus hypochondriacus (AhNF-YC) was further characterized by its overexpression in transgenic Arabidospis thaliana plants. A role in development was inferred from modified growth rates in root, rosettes and inflorescences recorded in AhNF-YC overexpressing Arabidopsis plants, in addition to a delayed onset of flowering. Also, the overexpression of AhNF-YC caused increased seedling sensitivity to abscisic acid (ABA), and influenced the expression of several genes involved in secondary metabolism, development and ABA-related responses. An altered expression of the latter in water stressed and recovered transgenic plants, together with the observed increase in ABA sensitivity, suggested that their increased water stress resistance was partly ABA-dependent. An untargeted metabolomic analysis also revealed an altered metabolite pattern, both in normal and water stress/recovery conditions. These results suggest that AhNF-YC may play an important regulatory role in both development and stress, and represents a candidate gene for the engineering of abiotic stress resistance in commercial crops. PMID:26475185

  8. Artemisia annua increases resistance to heat and oxidative stresses, but has no effect on lifespan in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Seung-Il OH

    2016-01-01

    Full Text Available Abstract It is suggested that oxidative stress induced by cellular reactive oxygen species is one of the major causal factors of aging. The effect of dietary supplementation of anti-oxidants on response to environmental stressors and lifespan has been studied in various model organisms. In the present study, we examine the effect of Artemisia annua extract on resistance to oxidative, heat, and ultraviolet stresses in the nematode Caenorhabditis elegans. Artemisia annua significantly increases survival under oxidative and heat stresses, however has no effects in response to ultraviolet stress. Then, we measured the in vivo changes in expression of stress-responsive genes by Artemisia annua using green fluorescence protein. The expression of hsp-16.2, known to be involved in response to heat stress, is significantly increased by Artemisia annua supplementation. An anti-oxidant gene, sod-3, was also up-regulated by Artemisia annua. However, both mean and maximum lifespan of Caenorhabditis elegans was not altered by dietary supplementation of Artemisia annua. These findings indicate that Artemisia annua confers health-promoting effects through increasing the resistance to environmental stressors and has no effect on lifespan in C. elegans. Our study suggests that Artemisia annua can be used for the development of novel natural therapeutics for diseases caused by environmental stressors.

  9. Gene-related strain variation of Staphylococcus aureus for homologous resistance response to acid stress.

    Science.gov (United States)

    Lee, Soomin; Ahn, Sooyeon; Lee, Heeyoung; Kim, Won-Il; Kim, Hwang-Yong; Ryu, Jae-Gee; Kim, Se-Ri; Choi, Kyoung-Hee; Yoon, Yohan

    2014-10-01

    This study investigated the effect of adaptation of Staphylococcus aureus strains to the acidic condition of tomato in response to environmental stresses, such as heat and acid. S. aureus ATCC 13565, ATCC 14458, ATCC 23235, ATCC 27664, and NCCP10826 habituated in tomato extract at 35°C for 24 h were inoculated in tryptic soy broth. The culture suspensions were then subjected to heat challenge or acid challenge at 60°C and pH 3.0, respectively, for 60 min. In addition, transcriptional analysis using quantitative real-time PCR was performed to evaluate the expression level of acid-shock genes, such as clpB, zwf, nuoF, and gnd, from five S. aureus strains after the acid habituation of strains in tomato at 35°C for 15 min and 60 min in comparison with that of the nonhabituated strains. In comparison with the nonhabituated strains, the five tomato-habituated S. aureus strains did not show cross protection to heat, but tomato-habituated S. aureus ATCC 23235 showed acid resistance. In quantitative real-time-PCR analysis, the relative expression levels of acid-shock genes (clpB, zwf, nuoF, and gnd) were increased the most in S. aureus ATCC 23235 after 60 min of tomato habituation, but there was little difference in the expression levels among the five S. aureus strains after 15 min of tomato habituation. These results indicate that the variation of acid resistance of S. aureus is related to the expression of acid-shock genes during acid habituation. PMID:25285500

  10. Supplementing dietary sugar promotes endoplasmic reticulum stress-independent insulin resistance and fatty liver in goose.

    Science.gov (United States)

    Geng, Tuoyu; Zhao, Xing; Xia, Lili; Liu, Long; Li, Fuyuan; Yang, Biao; Wang, Qianqian; Montgomery, Sean; Cui, Hengmi; Gong, Daoqing

    2016-08-01

    It is known that endoplasmic reticulum stress (ERS) contributes to insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) in mammals. However, we recently demonstrated that overfeeding with a traditional diet (mainly consisting of cooked maize) does not induce ERS in goose. As cellular studies show that high glucose and palmitate can trigger ERS in mammalian cells, we hypothesized that supplementing sugar to the traditional diet could induce ERS, thus promoting insulin resistance and fatty liver. To test the hypothesis, we first treated goose primary hepatocytes with high glucose (25 mM and 50 mM) and palmitate (0.5 mM) supplemented with or without 0.25 mM oleate. Data indicated that, as in mammalian cells, high glucose and palmitate indeed induced ERS in goose primary hepatocytes, and palmitate-induced ERS was suppressed by supplemental 0.25 mM oleate. We then tested the hypothesis with an in vivo study, in which Landes geese overfed with traditional or novel diets (i.e., the traditional diet supplemented with sugar) were compared with control geese (normally fed with cooked maize) for ERS, IR and fatty liver. The differences in glucose tolerance, insulin tolerance and postprandial blood glucose between the geese overfed with traditional and novel diets suggested that supplementing dietary sugar promoted IR. This promotion was accompanied with an increasing trend of liver weight and abdominal fat weight relative to body weight. Surprisingly, compared to overfeeding with the traditional diet, overfeeding with the novel diet did not induce ERS, even further suppressed ERS in goose fatty liver. Together, our findings suggest that supplementing dietary sugar promotes ERS-independent IR and fatty liver in goose. It is intriguing to discover the factor(s) protecting goose liver from ERS as well as the non-ERS mechanism underlying IR. PMID:27246737

  11. Repeated exposure to heat stress results in a diaphragm phenotype that resists ventilator-induced diaphragm dysfunction.

    Science.gov (United States)

    Yoshihara, Toshinori; Ichinoseki-Sekine, Noriko; Kakigi, Ryo; Tsuzuki, Takamasa; Sugiura, Takao; Powers, Scott K; Naito, Hisashi

    2015-11-01

    Controlled mechanical ventilation (CMV) is a life-saving intervention for patients in respiratory failure. Unfortunately, prolonged mechanical ventilation (MV) results in diaphragmatic atrophy and contractile dysfunction, both of which are predicted to contribute to problems in weaning patients from the ventilator. Therefore, developing a strategy to protect the diaphragm against ventilator-induced weakness is important. We tested the hypothesis that repeated bouts of heat stress result in diaphragm resistance against CMV-induced atrophy and contractile dysfunction. Male Wistar rats were randomly divided into six experimental groups: 1) control; 2) single bout of whole body heat stress; 3) repeated bouts of whole body heat stress; 4) 12 h CMV; 5) single bout of whole body heat stress 24 h before CMV; and 6) repeated bouts of whole body heat stress 1, 3, and 5 days before 12 h of CMV. Our results revealed that repeated bouts of heat stress resulted in increased levels of heat shock protein 72 in the diaphragm and protection against both CMV-induced diaphragmatic atrophy and contractile dysfunction at submaximal stimulation frequencies. The specific mechanisms responsible for this protection remain unclear: this heat stress-induced protection against CMV-induced diaphragmatic atrophy and weakness may be partially due to reduced diaphragmatic oxidative stress, diminished activation of signal transducer/transcriptional activator-3, lower caspase-3 activation, and decreased autophagy in the diaphragm.

  12. Glutamate Dehydrogenase Is Required by Mycobacterium bovis BCG for Resistance to Cellular Stress.

    Directory of Open Access Journals (Sweden)

    James L Gallant

    Full Text Available We recently reported on our success to generate deletion mutants of the genes encoding glutamate dehydrogenase (GDH and glutamine oxoglutarate aminotransferase (GOGAT in M. bovis BCG, despite their in vitro essentiality in M. tuberculosis. We could use these mutants to delineate the roles of GDH and GOGAT in mycobacterial nitrogen metabolism by using M. bovis BCG as a model for M. tuberculosis specifically. Here, we extended our investigation towards the involvement of GDH and GOGAT in other aspects of M. bovis BCG physiology, including the use of glutamate as a carbon source and resistance to known phagosomal stresses, as well as in survival inside macrophages. We find that gdh is indispensable for the utilization of glutamate as a major carbon source, in low pH environments and when challenged with nitric oxide. On the other hand, the gltBD mutant had increased viability under low pH conditions and was unaffected by a challenge with nitric oxide. Strikingly, GDH was required to sustain M. bovis BCG during infection of both murine RAW 264.7 and bone-marrow derived and macrophages, while GOGAT was not. We conclude that the catabolism of glutamate in slow growing mycobacteria may be a crucial function during infection of macrophage cells and demonstrate a novel requirement for M. bovis BCG GDH in the protection against acidic and nitrosative stress. These results provide strong clues on the role of GDH in intracellular survival of M. tuberculosis, in which the essentiality of the gdh gene complicates knock out studies making the study of the role of this enzyme in pathogenesis difficult.

  13. Metformin protects rat hepatocytes against bile acid-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Titia E Woudenberg-Vrenken

    Full Text Available BACKGROUND: Metformin is used in the treatment of Diabetes Mellitus type II and improves liver function in patients with non-alcoholic fatty liver disease (NAFLD. Metformin activates AMP-activated protein kinase (AMPK, the cellular energy sensor that is sensitive to changes in the AMP/ATP-ratio. AMPK is an inhibitor of mammalian target of rapamycin (mTOR. Both AMPK and mTOR are able to modulate cell death. AIM: To evaluate the effects of metformin on hepatocyte cell death. METHODS: Apoptotic cell death was induced in primary rat hepatocytes using either the bile acid glycochenodeoxycholic acid (GCDCA or TNFα in combination with actinomycin D (actD. AMPK, mTOR and phosphoinositide-3 kinase (PI3K/Akt were inhibited using pharmacological inhibitors. Apoptosis and necrosis were quantified by caspase activation, acridine orange staining and Sytox green staining respectively. RESULTS: Metformin dose-dependently reduces GCDCA-induced apoptosis, even when added 2 hours after GCDCA, without increasing necrotic cell death. Metformin does not protect against TNFα/ActD-induced apoptosis. The protective effect of metformin is dependent on an intact PI3-kinase/Akt pathway, but does not require AMPK/mTOR-signaling. Metformin does not inhibit NF-κB activation. CONCLUSION: Metformin protects against bile acid-induced apoptosis and could be considered in the treatment of chronic liver diseases accompanied by inflammation.

  14. Mutations in mmpL and in the cell wall stress stimulon contribute to resistance to oxadiazole antibiotics in methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Xiao, Qiaobin; Vakulenko, Sergei; Chang, Mayland; Mobashery, Shahriar

    2014-10-01

    Staphylococcus aureus is a leading cause of hospital- and community-acquired infections, which exhibit broad resistance to various antibiotics. We recently disclosed the discovery of the oxadiazole class of antibiotics, which has in vitro and in vivo activities against methicillin-resistant S. aureus (MRSA). We report herein that MmpL, a putative member of the resistance, nodulation, and cell division (RND) family of proteins, contributes to oxadiazole resistance in the S. aureus strain COL. Through serial passages, we generated two S. aureus COL variants that showed diminished susceptibilities to an oxadiazole antibiotic. The MICs for the oxadiazole against one strain (designated S. aureus COL(I)) increased reproducibly 2-fold (to 4 μg/ml), while against the other strain (S. aureus COL(R)), they increased >4-fold (to >8 μg/ml, the limit of solubility). The COL(R) strain was derived from the COL(I) strain. Whole-genome sequencing revealed 31 mutations in S. aureus COL(R), of which 29 were shared with COL(I). Consistent with our previous finding that oxadiazole antibiotics inhibit cell wall biosynthesis, we found 13 mutations that occurred either in structural genes or in promoters of the genes of the cell wall stress stimulon. Two unique mutations in S. aureus COL(R) were substitutions in two genes that encode the putative thioredoxin (SACOL1794) and MmpL (SACOL2566). A role for mmpL in resistance to oxadiazoles was discerned from gene deletion and complementation experiments. To our knowledge, this is the first report that a cell wall-acting antibiotic selects for mutations in the cell wall stress stimulon and the first to implicate MmpL in resistance to antibiotics in S. aureus.

  15. Development of a stress inducer for the test of radiation resistivity of organic materials used under the strain

    Energy Technology Data Exchange (ETDEWEB)

    Nunome, Keichi; Okazaki, Masaharu; Tai, Yutaka (Government Industrial Research Inst., Nagoya (Japan))

    1991-06-01

    A stress inducer for testing the radiation resistivity of organic materials under the strain was developed. The apparatus consists of, (1) stepping motor control system, which is set outside the radiation room, (2) stepping motor protected from radiation in a lead box inside the radiation room, and (3) stress inducing head which is set near the radiation source of {sup 60}Co. Two kinds of stresses, due to either bending or twisting of the sample, can be generated in the test piece during the simultaneous irradiation. As a test run of the apparatus, low density polyethylene rods were irradiated under the stress due to bending to the sample. Changes in the 'hardness' of the material were evaluated by {sup 13}C spin relaxation using high resolution solid state MMR technique. (author).

  16. Transcriptome Profiling Revealed Stress-Induced and Disease Resistance Genes Up-Regulated in PRSV Resistant Transgenic Papaya

    OpenAIRE

    Fang, Jingping; Lin, Aiting; Qiu, Weijing; Cai, Hanyang; Umar, Muhammad; Chen, Rukai; Ming, Ray

    2016-01-01

    Papaya is a productive and nutritious tropical fruit. Papaya Ringspot Virus (PRSV) is the most devastating pathogen threatening papaya production worldwide. Development of transgenic resistant varieties is the most effective strategy to control this disease. However, little is known about the genome-wide functional changes induced by particle bombardment transformation. We conducted transcriptome sequencing of PRSV resistant transgenic papaya SunUp and its PRSV susceptible progenitor Sunset t...

  17. Farmers' perceptions and knowledge of cattle adaptation to heat stress and tick resistance in the eastern cape, South Africa.

    Science.gov (United States)

    Katiyatiya, C L F; Muchenje, V; Mushunje, A

    2014-11-01

    The objective of this study was to determine the perceptions and knowledge of farmers of heat stress and tick resistance in cattle. A cross-sectional survey was conducted and 110 farmers in four villages in the sour and sweet velds of the Eastern Cape Province, South Africa were interviewed. The associations among area (municipality), gender, age, level of education, employment and religion were computed using Chi-square tests. The majority of the respondents had on average 4 bulls, 4 cows, 4 heifers, 4 calves, and 4 oxen. Milk was considered as the major (28.3%) reason for keeping cattle. Most farmers owned non-descript (72.6%), and Nguni (45.3%) cattle because of their heat tolerance (54.7%), tick resistance (54.7%), and milking ability (28.2%) traits. Excessive panting (56.6%) and disease transmission (76%) were regarded as the major effects of heat stress and tick infestation in cattle, respectively. About 50% of the respondents agreed that hair length influences tick resistance and 47.17% considered coat colour when acquiring cattle. In the sampled areas, ticks were prevalent in the summer season (93%), and 77.36% of the respondents use acaricides every fortnight. Gall sickness was reported to be a major problem in the cattle herds by 36.79% of the respondents. Our results showed that farmers in the two municipalities had knowledge of cattle adaptation to heat stress and tick resistance. PMID:25358328

  18. Benefits of thread rolling process to the stress corrosion cracking and fatigue resistance of high strength fasteners

    Energy Technology Data Exchange (ETDEWEB)

    Kephart, A.R.; Hayden, S.Z.

    1993-05-01

    Stress corrosion cracking (SCC) behavior of cut (machined) vice thread rolled Alloy X-750 and Alloy 625 fasteners in a simulated high temperature primary water environment has been evaluated. SCC testing at 360 and 338C included 157 small and 40 large 60{degree} Vee thread studs. Thread rolled fasteners had improved resistance relative to cut fasteners. Tests of fatigue resistance in air at room temperature and both air and primary water at 315C were conducted on smaller studs with both cut and rolled threads. Results showed rolled threads can have significantly improved fatigue lives over those of cut threads in both air and primary water. Fasteners produced by two different thread rolling methods, in-feed (radial) and through-feed (axial), revealed similar SCC initiation test results. Testing of thread rolled fasteners revealed no significant SCC or fatigue growth of rolling induced thread crest laps typical of the thread rolling process. While fatigue resistance differed between the two rolled thread supplier`s studs, neither of the suppliers studs showed SCC initiation at exposure times beyond that of cut threads with SCC. In contrast to rolling at room temperature, warm rolled (427C) threads showed no improvement over cut threads in terms of fatigue resistance. The observed improved SCC and fatigue performance of rolled threads is postulated to be due to interactive factors, including beneficial residual stresses in critically stressed thread root region, reduction of plastic strains during loading and formation of favorable microstructure.

  19. Carbohydrate concentrations and freezing stress resistance of silver birch buds grown under elevated temperature and ozone.

    Science.gov (United States)

    Riikonen, Johanna; Kontunen-Soppela, Sari; Vapaavuori, Elina; Tervahauta, Arja; Tuomainen, Marjo; Oksanen, Elina

    2013-03-01

    The effects of slightly elevated temperature (+0.8 °C), ozone (O3) concentration (1.3 × ambient O3 concentration) and their combination on over-wintering buds of Betula pendula Roth were studied after two growing seasons of exposure in the field. Carbohydrate concentrations, freezing stress resistance (FSR), bud dry weight to fresh weight ratio, and transcript levels of cytochrome oxidase (COX), alternative oxidase (AOX) and dehydrin (LTI36) genes were studied in two clones (clones 12 and 25) in December. Elevated temperature increased the bud dry weight to fresh weight ratio and the ratio of raffinose family oligosaccharides to sucrose and the transcript levels of the dehydrin (LTI36) gene (in clone 12 only), but did not alter the FSR of the buds. Genotype-specific alterations in carbohydrate metabolism were found in the buds grown under elevated O3. The treatments did not significantly affect the transcript level of the COX or AOX genes. No clear pattern of an interactive effect between elevated temperature and O3 concentration was found. According to these data, the increase in autumnal temperatures and slightly increasing O3 concentrations do not increase the risk for freeze-induced damage in winter in silver birch buds, although some alterations in bud physiology occur.

  20. Meiotic chromosome mobility in fission yeast is resistant to environmental stress.

    Science.gov (United States)

    Illner, Doris; Lorenz, Alexander; Scherthan, Harry

    2016-01-01

    The formation of healthy gametes requires pairing of homologous chromosomes (homologs) as a prerequisite for their correct segregation during meiosis. Initially, homolog alignment is promoted by meiotic chromosome movements feeding into intimate homolog pairing by homologous recombination and/or synaptonemal complex formation. Meiotic chromosome movements in the fission yeast, Schizosaccharomyces pombe, depend on astral microtubule dynamics that drag the nucleus through the zygote; known as horsetail movement. The response of microtubule-led meiotic chromosome movements to environmental stresses such as ionizing irradiation (IR) and associated reactive oxygen species (ROS) is not known. Here, we show that, in contrast to budding yeast, the horsetail movement is largely radiation-resistant, which is likely mediated by a potent antioxidant defense. IR exposure of sporulating S. pombe cells induced misrepair and irreparable DNA double strand breaks causing chromosome fragmentation, missegregation and gamete death. Comparing radiation outcome in fission and budding yeast, and studying meiosis with poisoned microtubules indicates that the increased gamete death after IR is innate to fission yeast. Inhibition of meiotic chromosome mobility in the face of IR failed to influence the course of DSB repair, indicating that paralysis of meiotic chromosome mobility in a genotoxic environment is not a universal response among species. PMID:27074839

  1. Jatropha curcas L., a multipurpose stress resistant plant with a potential for ethnomedicine and renewable energy.

    Science.gov (United States)

    Debnath, Mousumi; Bisen, P S

    2008-08-01

    Jatropha curcas is a stress--resistant perennial plant growing on marginal soils. This plant is widespread throughout arid and semiarid tropical regions of the world and has been used as a traditional folk medicine in many countries. J.curcas is a source of several secondary metabolites of medicinal importance. The leaf, fruits, latex and bark contain glycosides, tannins, phytosterols, flavonoids and steroidal sapogenins that exhibit wide ranging medicinal properties. The plant products exhibit anti-bacterial and anti-fungal activities. The paper highlights the ability of various metabolites present in the plant to act as therapeutic agents and plant protectants. The plant is designated as an energy plant and use of J.curcas oil as biodiesel is a promising and commercially viable alternative to diesel oil. The seeds of the plant are not only a source of biodiesel but also contain several metabolites of pharmaceutical importance. Commercial exploitation for biopharmaceuticals and bio-energy production are some of the prospective future potential of this plant. Further reclamation of wastelands and dry lands is also possible with J.curcas cultivation.

  2. Effects of ginger (Zingiber officinale Roscoe supplementation and resistance training on some blood oxidative stress markers in obese men

    Directory of Open Access Journals (Sweden)

    Sirvan Atashak

    2014-06-01

    Full Text Available Excessive adiposity increases oxidative stress, and thus may play a critical role in the pathogenesis and development of obesity-associated comorbidities, in particular atherosclerosis, diabetes mellitus, and arterial hypertension. Improved body composition, through exercise training and diet, may therefore significantly contribute to a reduction in oxidative stress. Further, some foods high in antioxidants (e.g., ginger provide additional defense against oxidation. This study was conducted to assess the effects of ginger (Zingiber officinale Roscoe supplementation and progressive resistance training (PRT on some nonenzymatic blood [total antioxidant capacity (TAC and malondialdehyde (MDA] oxidative stress markers in obese men. Thirty-two obese males (body mass index ≥30, aged 18–30 years were randomized to one of the following four groups: a placebo (PL; n = 8; resistance training plus placebo (RTPL; n = 8; resistance training plus ginger supplementation (RTGI; n = 8; and ginger supplementation only (GI; n = 8. Participants in the RTGI and GI groups consumed 1 g ginger/day for 10 weeks. At the same time, PRT was undertaken by the RTPL and RTGI groups three times/week. Resting blood samples were collected at baseline and at 10 weeks, and analyzed for plasma nonenzymatic TAC and MDA concentration. After the 10-week intervention, we observed significant training × ginger supplementation × resistance training interaction for TAC (p = 0.043 and significant interactions for training × resistance training and training × ginger supplementation for MDA levels (p < 0.05. The results of this study show that 10 weeks of either ginger supplementation or PRT protects against oxidative stress and therefore both of these interventions can be beneficial for obese individuals; however, when combined, the effects cancel each other out.

  3. Adenylate cyclase and the cyclic AMP receptor protein modulate stress resistance and virulence capacity of uropathogenic Escherichia coli.

    Science.gov (United States)

    Donovan, Grant T; Norton, J Paul; Bower, Jean M; Mulvey, Matthew A

    2013-01-01

    In many bacteria, the second messenger cyclic AMP (cAMP) interacts with the transcription factor cAMP receptor protein (CRP), forming active cAMP-CRP complexes that can control a multitude of cellular activities, including expanded carbon source utilization, stress response pathways, and virulence. Here, we assessed the role of cAMP-CRP as a regulator of stress resistance and virulence in uropathogenic Escherichia coli (UPEC), the principal cause of urinary tract infections worldwide. Deletion of genes encoding either CRP or CyaA, the enzyme responsible for cAMP synthesis, attenuates the ability of UPEC to colonize the bladder in a mouse infection model, dependent on intact innate host defenses. UPEC mutants lacking cAMP-CRP grow normally in the presence of glucose but are unable to utilize alternate carbon sources like amino acids, the primary nutrients available to UPEC within the urinary tract. Relative to the wild-type UPEC isolate, the cyaA and crp deletion mutants are sensitive to nitrosative stress and the superoxide generator methyl viologen but remarkably resistant to hydrogen peroxide (H(2)O(2)) and acid stress. In the mutant strains, H(2)O(2) resistance correlates with elevated catalase activity attributable in part to enhanced translation of the alternate sigma factor RpoS. Acid resistance was promoted by both RpoS-independent and RpoS-dependent mechanisms, including expression of the RpoS-regulated DNA-binding ferritin-like protein Dps. We conclude that balanced input from many cAMP-CRP-responsive elements, including RpoS, is critical to the ability of UPEC to handle the nutrient limitations and severe environmental stresses present within the mammalian urinary tract.

  4. Differing endoplasmic reticulum stress response to excess lipogenesis versus lipid oversupply in relation to hepatic steatosis and insulin resistance.

    Directory of Open Access Journals (Sweden)

    Lu-Ping Ren

    Full Text Available Mitochondrial dysfunction and endoplasmic reticulum (ER stress have been implicated in hepatic steatosis and insulin resistance. The present study investigated their roles in the development of hepatic steatosis and insulin resistance during de novo lipogenesis (DNL compared to extrahepatic lipid oversupply. Male C57BL/6J mice were fed either a high fructose (HFru or high fat (HFat diet to induce DNL or lipid oversupply in/to the liver. Both HFru and HFat feeding increased hepatic triglyceride within 3 days (by 3.5 and 2.4 fold and the steatosis remained persistent from 1 week onwards (p<0.01 vs Con. Glucose intolerance (iAUC increased by ∼60% and blunted insulin-stimulated hepatic Akt and GSK3β phosphorylation (∼40-60% were found in both feeding conditions (p<0.01 vs Con, assessed after 1 week. No impairment of mitochondrial function was found (oxidation capacity, expression of PGC1α, CPT1, respiratory complexes, enzymatic activity of citrate synthase & β-HAD. As expected, DNL was increased (∼60% in HFru-fed mice and decreased (32% in HFat-fed mice (all p<0.05. Interestingly, associated with the upregulated lipogenic enzymes (ACC, FAS and SCD1, two (PERK/eIF2α and IRE1/XBP1 of three ER stress pathways were significantly activated in HFru-fed mice. However, no significant ER stress was observed in HFat-fed mice during the development of hepatic steatosis. Our findings indicate that HFru and HFat diets can result in hepatic steatosis and insulin resistance without obvious mitochondrial defects via different lipid metabolic pathways. The fact that ER stress is apparent only with HFru feeding suggests that ER stress is involved in DNL per se rather than resulting from hepatic steatosis or insulin resistance.

  5. HORMONAL PROFILE AND NONSPECIFIC RESISTANCE IN BOAR UNDER PRE-SLAUGHTER STRESS

    Directory of Open Access Journals (Sweden)

    S.S. Grabovskyi

    2016-03-01

    . The insulin concentration of І experimental and control groups boars was higher after transportation with comparing beforetransportation to meat plant. All nonspecific body resistance parameters significantly increased in boars blood, which in addition to food received spleen extract, compared with the control group animals after transportation before slaughter: phagocytic activity increased at 12 %, phagocytic index — 13 % and phagocytic number — 14 %. On the boars’ feeding final stage is necessary to consider a pre-slaughter stress and to apply of natural origin biologically active substances. The results can be used on other farm animals for resistance increasing, correction and avoid their pre-slaughter stress and improve the product quality.

  6. Resistance to Aspergillus flavus in maize and peanut:Molecular biology, breeding, environmental stress,and future perspectives

    Institute of Scientific and Technical Information of China (English)

    Jake; C.Fountain; Pawan; Khera; Liming; Yang; Spurthi; N.Nayak; Brian; T.Scully; Robert; D.Lee; Zhi-Yuan; Chen; Robert; C.Kemerait; Rajeev; K.Varshney; Baozhu; Guo

    2015-01-01

    The colonization of maize(Zea mays L.) and peanut(Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species(ROS) within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A.flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

  7. Resistance to Aspergillus flavus in maize and peanut:Molecular biology, breeding, environmental stress, and future perspectives

    Institute of Scientific and Technical Information of China (English)

    Jake C. Fountain; Baozhu Guo; Pawan Khera; Liming Yang; Spurthi N. Nayak; Brian T. Scully; Robert D. Lee; Zhi-Yuan Chen; Robert C. Kemerait; Rajeev K. Varshney

    2015-01-01

    The colonization of maize (Zea mays L.) and peanut (Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species (ROS) within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A. flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

  8. Resilience to stress and disturbance, and resistance to Bromus tectorum l. invasion in cold desert shrublands of western North America

    Science.gov (United States)

    Chambers, Jeanne C.; Bradley, Bethany A.; Brown, Cynthia S.; D'Antonio, Carla; Germino, Matthew J.; Grace, James B.; Hardegree, Stuart P.; Miller, Richard F.; Pyke, David A.

    2013-01-01

    Alien grass invasions in arid and semi-arid ecosystems are resulting in grass–fire cycles and ecosystem-level transformations that severely diminish ecosystem services. Our capacity to address the rapid and complex changes occurring in these ecosystems can be enhanced by developing an understanding of the environmental factors and ecosystem attributes that determine resilience of native ecosystems to stress and disturbance, and resistance to invasion. Cold desert shrublands occur over strong environmental gradients and exhibit significant differences in resilience and resistance. They provide an excellent opportunity to increase our understanding of these concepts. Herein, we examine a series of linked questions about (a) ecosystem attributes that determine resilience and resistance along environmental gradients, (b) effects of disturbances like livestock grazing and altered fire regimes and of stressors like rapid climate change, rising CO2, and N deposition on resilience and resistance, and (c) interacting effects of resilience and resistance on ecosystems with different environmental conditions. We conclude by providing strategies for the use of resilience and resistance concepts in a management context. At ecological site scales, state and transition models are used to illustrate how differences in resilience and resistance influence potential alternative vegetation states, transitions among states, and thresholds. At landscape scales management strategies based on resilience and resistance—protection, prevention, restoration, and monitoring and adaptive management—are used to determine priority management areas and appropriate actions.

  9. Verification of the resistance of a LEA gene from Tamarix expression in Saccharomyces cerevisiae to abiotic stresses

    Institute of Scientific and Technical Information of China (English)

    WANG Bing-feng; WANG Yu-cheng; ZHANG Da-wei; LI Hong-yan; YANG Chuan-ping

    2008-01-01

    The role of late embryogenesis abundant (LEA) proteins in stress tolerance was examined by using a yeast expression system. LEA protein tolerance to the abotic stresses in plants involved in salt, drought and freezing stresses and additional tolerance to heat, NaHCO3 (salt-alkali) and ultraviolet radiation was also investigated. The transgenic yeast harboring the Tamarix LEA gene (DQ663481) was generated under the control of inducible GAL promoter (pYES2 vector), yeast cells transformed with pYES2 empty vector were also generated as a control. Stress tolerance tests showed that LEA yeast transformants exhibited a higher survival rates than the control transformants under high temperature, NaHCO3, ultraviolet radiation, salt (NaCl), drought and freezing, indicating that the LEA gene is tolerant to these abiotic stresses. These results suggest that the LEA gene is resistant to a wider repertoire of stresses and may play a common role in plant acclimation to the examined stress conditions.

  10. Stress-induced resistance to the fear memory labilization/reconsolidation process. Involvement of the basolateral amygdala complex.

    Science.gov (United States)

    Espejo, Pablo Javier; Ortiz, Vanesa; Martijena, Irene Delia; Molina, Victor Alejandro

    2016-10-01

    Consolidated memories can enter into a labile state after reactivation followed by a restabilization process defined as reconsolidation. This process can be interfered with Midazolam (MDZ), a positive allosteric modulator of the GABA-A receptor. The present study has evaluated the influence of prior stress on MDZ's interfering effect. We also assessed the influence of both systemic and intra-basolateral amygdala (BLA) infusion of d-cycloserine (DCS), a partial agonist of the NMDA receptors, on the MDZ effect in previously stressed rats. Furthermore, we analyzed the effect of stress on the expression of Zif-268 and the GluN2B sites, two molecular markers of the labilization/reconsolidation process, following reactivation. The results revealed that prior stress resulted into a memory trace that was insensitive to the MDZ impairing effect. Both systemic and intra-BLA DCS administration previous to reactivation restored MDZ's disruptive effect on memory reconsolidation in stressed animals. Further, reactivation enhanced Zif-268 expression in the BLA in control unstressed rats, whereas no elevation was observed in stressed animals. In agreement with the behavioral findings, DCS restored the increased level of Zif-268 expression in the BLA in stressed animals. Moreover, memory reactivation in unstressed animals elevated GluN2B expression in the BLA, thus suggesting that this effect is involved in memory destabilization, whereas stressed animals did not reveal any changes. These findings are consistent with resistance to the MDZ effect in these rats, indicating that stress exposure prevents the onset of destabilization following reactivation. In summary, prior stress limited both the occurrence of the reactivation-induced destabilization and restabilization. PMID:27378335

  11. Nisin Resistance of Listeria monocytogenes Is Increased by Exposure to Salt Stress and Is Mediated via LiaR

    OpenAIRE

    Bergholz, Teresa M.; Tang, Silin; Wiedmann, Martin; Boor, Kathryn J.

    2013-01-01

    Growth of Listeria monocytogenes on refrigerated, ready-to-eat food is a significant food safety concern. Natural antimicrobials, such as nisin, can be used to control this pathogen on food, but little is known about how other food-related stresses may impact how the pathogen responds to these compounds. Prior work demonstrated that exposure of L. monocytogenes to salt stress at 7°C led to increased expression of genes involved in nisin resistance, including the response regulator liaR. We hy...

  12. A Key ABA Catabolic Gene, OsABA8ox3, Is Involved in Drought Stress Resistance in Rice

    OpenAIRE

    Shanlan Cai; Guobin Jiang; Nenghui Ye; Zhizhan Chu; Xuezhong Xu; Jianhua Zhang; Guohui Zhu

    2015-01-01

    Expressions of ABA biosynthesis genes and catabolism genes are generally co-regulated in plant development and responses to environmental stress. Up-regulation of OsNCED3 gene, a key gene in ABA biosynthesis, has been suggested as a way to enhance plant drought resistance but little is known for the role of ABA catabolic genes during drought stress. In this study, we found that OsABA8ox3 was the most highly expressed gene of the OsABA8ox family in rice leaves. Expression of OsABA8ox3 was prom...

  13. Effects of simulated microgravity on surfactant and water balance of lung in animals with different resistance to stress

    Science.gov (United States)

    Bryndina, Irina; Vasilieva, Natalia

    Weightlessness is accompanied by redistribution of blood flow in lung, changes of lung volumes and gas exchange (Prisk et al., 2002; Grigoriev, Baranov, 2003). On the other hand, it is known that microgravity is considered as a kind of moderate stress (Grigoriev et al., 2004). Stress response may differ in animals resistant or vulnerable to stress (Sudakov, 2007). To study the effects of simulated microgravity upon lung, we used 20 male albino rats tested for behavior in the "open field" and than divided into active (stress resistant - SR ) and passive (stress vulnerable - CV) groups. Two mouse lines were used with similar goal - C57Bl/6 and BALB/c mice (n=16). According to data obtained earlier, BALB/c mice referred as more stress vulnerable, in contrast to C57BL/6 mice, which are considered to be relatively stress resistant (Flint et al., 2007). We have previously shown that changes in lung surfactant system after psychosocial stress or long-term immobilization are less pronounced in stress resistant rats (Vasilieva, Bryndina, 2012). The aim of this work is to study the properties and biochemical composition of pulmonary surfactant and lung water balance in rats and mice with different stress resistance in antiorthostatic suspension (AOS) of short and long duration. Simulated microgravity was reproduced according to procedure of Ilyin-Novikov in modification of Morey-Holton. The duration of exposure was 10 days for rats and 30 days for mice. The properties of pulmonary surfactant were assessed by the evaluation of surface activity (surface tension - ST), the content of total phospholipids (PL) and their fractions. Simultaneously we calculated the gravimetric water balance indices: lung coefficient, "dry residue" and wet-to-dry ratio. Total and extravascular lung fluid and pulmonary blood supply were estimated as well. The experiments demonstrated that there was a decrease of surface tension of surfactant films after 10-day AOS in both groups of rats (to a greater

  14. Mitochondrial DNA damage and dysfunction, and oxidative stress are associated with endoplasmic reticulum stress, protein degradation and apoptosis in high fat diet-induced insulin resistance mice.

    Directory of Open Access Journals (Sweden)

    Larysa V Yuzefovych

    Full Text Available BACKGROUND: Recent studies showed a link between a high fat diet (HFD-induced obesity and lipid accumulation in non-adipose tissues, such as skeletal muscle and liver, and insulin resistance (IR. Although the mechanisms responsible for IR in those tissues are different, oxidative stress and mitochondrial dysfunction have been implicated in the disease process. We tested the hypothesis that HFD induced mitochondrial DNA (mtDNA damage and that this damage is associated with mitochondrial dysfunction, oxidative stress, and induction of markers of endoplasmic reticulum (ER stress, protein degradation and apoptosis in skeletal muscle and liver in a mouse model of obesity-induced IR. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6J male mice were fed either a HFD (60% fat or normal chow (NC (10% fat for 16 weeks. We found that HFD-induced IR correlated with increased mtDNA damage, mitochondrial dysfunction and markers of oxidative stress in skeletal muscle and liver. Also, a HFD causes a change in the expression level of DNA repair enzymes in both nuclei and mitochondria in skeletal muscle and liver. Furthermore, a HFD leads to activation of ER stress, protein degradation and apoptosis in skeletal muscle and liver, and significantly reduced the content of two major proteins involved in insulin signaling, Akt and IRS-1 in skeletal muscle, and Akt in liver. Basal p-Akt level was not significantly influenced by HFD feeding in skeletal muscle and liver. CONCLUSIONS/SIGNIFICANCE: This study provides new evidence that HFD-induced mtDNA damage correlates with mitochondrial dysfunction and increased oxidative stress in skeletal muscle and liver, which is associated with the induction of markers of ER stress, protein degradation and apoptosis.

  15. Rapid growth reduces cold resistance: evidence from latitudinal variation in growth rate, cold resistance and stress proteins.

    Directory of Open Access Journals (Sweden)

    Robby Stoks

    Full Text Available BACKGROUND: Physiological costs of rapid growth may contribute to the observation that organisms typically grow at submaximal rates. Although, it has been hypothesized that faster growing individuals would do worse in dealing with suboptimal temperatures, this type of cost has never been explored empirically. Furthermore, the mechanistic basis of the physiological costs of rapid growth is largely unexplored. METHODOLOGY/PRINCIPAL FINDING: Larvae of the damselfly Ischnura elegans from two univoltine northern and two multivoltine southern populations were reared at three temperatures and after emergence given a cold shock. Cold resistance, measured by chill coma recovery times in the adult stage, was lower in the southern populations. The faster larval growth rates in the southern populations contributed to this latitudinal pattern in cold resistance. In accordance with their assumed role in cold resistance, Hsp70 levels were lower in the southern populations, and faster growing larvae had lower Hsp70 levels. Yet, individual variation in Hsp70 levels did not explain variation in cold resistance. CONCLUSIONS/SIGNIFICANCE: WE PROVIDE EVIDENCE FOR A NOVEL COST OF RAPID GROWTH: reduced cold resistance. Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates. This also illustrates that stressors imposed in the larval stage may carry over and shape fitness in the adult stage and highlights the importance of physiological costs in the evolution of life-histories at macro-scales.

  16. A key ABA catabolic gene, OsABA8ox3, is involved in drought stress resistance in rice.

    Directory of Open Access Journals (Sweden)

    Shanlan Cai

    Full Text Available Expressions of ABA biosynthesis genes and catabolism genes are generally co-regulated in plant development and responses to environmental stress. Up-regulation of OsNCED3 gene, a key gene in ABA biosynthesis, has been suggested as a way to enhance plant drought resistance but little is known for the role of ABA catabolic genes during drought stress. In this study, we found that OsABA8ox3 was the most highly expressed gene of the OsABA8ox family in rice leaves. Expression of OsABA8ox3 was promptly induced by rehydration after PEG-mimic dehydration, a tendency opposite to the changes of ABA level. We therefore constructed rice OsABA8ox3 silencing (RNA interference, RNAi and overexpression plants. There were no obvious phenotype differences between the transgenic seedlings and wild type under normal condition. However, OsABA8ox3 RNAi lines showed significant improvement in drought stress tolerance while the overexpression seedlings were hypersensitive to drought stress when compared with wild type in terms of plant survival rates after 10 days of unwatering. Enzyme activity analysis indicated that OsABA8ox3 RNAi plants had higher superoxide dismutase (SOD and catalase (CAT activities and less malondialdehyde (MDA content than those of wild type when the plants were exposed to dehydration treatment, indicating a better anti-oxidative stress capability and less membrane damage. DNA microarray and real-time PCR analysis under dehydration treatment revealed that expressions of a group of stress/drought-related genes, i.e. LEA genes, were enhanced with higher transcript levels in OsABA8ox3 RNAi transgenic seedlings. We therefore conclude that that OsABA8ox3 gene plays an important role in controlling ABA level and drought stress resistance in rice.

  17. A key ABA catabolic gene, OsABA8ox3, is involved in drought stress resistance in rice.

    Science.gov (United States)

    Cai, Shanlan; Jiang, Guobin; Ye, Nenghui; Chu, Zhizhan; Xu, Xuezhong; Zhang, Jianhua; Zhu, Guohui

    2015-01-01

    Expressions of ABA biosynthesis genes and catabolism genes are generally co-regulated in plant development and responses to environmental stress. Up-regulation of OsNCED3 gene, a key gene in ABA biosynthesis, has been suggested as a way to enhance plant drought resistance but little is known for the role of ABA catabolic genes during drought stress. In this study, we found that OsABA8ox3 was the most highly expressed gene of the OsABA8ox family in rice leaves. Expression of OsABA8ox3 was promptly induced by rehydration after PEG-mimic dehydration, a tendency opposite to the changes of ABA level. We therefore constructed rice OsABA8ox3 silencing (RNA interference, RNAi) and overexpression plants. There were no obvious phenotype differences between the transgenic seedlings and wild type under normal condition. However, OsABA8ox3 RNAi lines showed significant improvement in drought stress tolerance while the overexpression seedlings were hypersensitive to drought stress when compared with wild type in terms of plant survival rates after 10 days of unwatering. Enzyme activity analysis indicated that OsABA8ox3 RNAi plants had higher superoxide dismutase (SOD) and catalase (CAT) activities and less malondialdehyde (MDA) content than those of wild type when the plants were exposed to dehydration treatment, indicating a better anti-oxidative stress capability and less membrane damage. DNA microarray and real-time PCR analysis under dehydration treatment revealed that expressions of a group of stress/drought-related genes, i.e. LEA genes, were enhanced with higher transcript levels in OsABA8ox3 RNAi transgenic seedlings. We therefore conclude that that OsABA8ox3 gene plays an important role in controlling ABA level and drought stress resistance in rice. PMID:25647508

  18. EPs7630(®) from Pelargonium sidoides increases stress resistance in Caenorhabditis elegans probably via the DAF-16/FOXO pathway.

    Science.gov (United States)

    Rezaizadehnajafi, Leila; Wink, Michael

    2014-03-15

    EPs7630(®) a water alcohol extract of the roots from Pelargonium sidoides contains several secondary metabolites including highly oxygenated coumarins, various phenolics and polyphenols. Using the DPPH assay to measure antioxidant activity a free radical scavenging activity of 14.7±0.85μg/ml (IC50) was determined. As an in vivo model Caenorhabditis elegans was applied to study the effect of EPs7630(®) on stress resistance. EPs7630(®) treatment reduces intracellular hsp-16.2::GFP expression (induced by the pro-oxidant juglone) indicating that the secondary metabolites of EPs7630(®) are bioavailable and exhibit antioxidant activities in vivo. Application of EPs7630(®) (50μg/ml) to the transgenic mutant TJ356 induced the migration of the transcription factor DAF-16 from cytosol to the nucleus, suggesting a prominent role of DAF-16/FOXO in the daf-2 pathway for stress resistance. PMID:24252337

  19. EPs7630(®) from Pelargonium sidoides increases stress resistance in Caenorhabditis elegans probably via the DAF-16/FOXO pathway.

    Science.gov (United States)

    Rezaizadehnajafi, Leila; Wink, Michael

    2014-03-15

    EPs7630(®) a water alcohol extract of the roots from Pelargonium sidoides contains several secondary metabolites including highly oxygenated coumarins, various phenolics and polyphenols. Using the DPPH assay to measure antioxidant activity a free radical scavenging activity of 14.7±0.85μg/ml (IC50) was determined. As an in vivo model Caenorhabditis elegans was applied to study the effect of EPs7630(®) on stress resistance. EPs7630(®) treatment reduces intracellular hsp-16.2::GFP expression (induced by the pro-oxidant juglone) indicating that the secondary metabolites of EPs7630(®) are bioavailable and exhibit antioxidant activities in vivo. Application of EPs7630(®) (50μg/ml) to the transgenic mutant TJ356 induced the migration of the transcription factor DAF-16 from cytosol to the nucleus, suggesting a prominent role of DAF-16/FOXO in the daf-2 pathway for stress resistance.

  20. Farmers’ Perceptions and Knowledge of Cattle Adaptation to Heat Stress and Tick Resistance in the Eastern Cape, South Africa

    OpenAIRE

    Katiyatiya, C. L. F.; V. Muchenje; Mushunje, A.

    2014-01-01

    The objective of this study was to determine the perceptions and knowledge of farmers of heat stress and tick resistance in cattle. A cross-sectional survey was conducted and 110 farmers in four villages in the sour and sweet velds of the Eastern Cape Province, South Africa were interviewed. The associations among area (municipality), gender, age, level of education, employment and religion were computed using Chi-square tests. The majority of the respondents had on average 4 bulls, 4 cows, 4...

  1. Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillside*

    OpenAIRE

    Chen, Xin; Yang, Yi-song; Tang, Jian-Jun

    2004-01-01

    Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized com...

  2. Copper-resistant bacteria reduces oxidative stress and uptake of copper in lentil plants: potential for bacterial bioremediation.

    Science.gov (United States)

    Islam, Faisal; Yasmeen, Tahira; Ali, Qasim; Mubin, Muhammad; Ali, Shafaqat; Arif, Muhammad Saleem; Hussain, Sabir; Riaz, Muhammad; Abbas, Farhat

    2016-01-01

    For effective microbe-assisted bioremediation, metal-resistant plant growth-promoting bacteria (PGPB) must facilitate plant growth by restricting excess metal uptake in plants, leading to prevent its bio-amplification in the ecosystem. The aims of our study were to isolate and characterize copper (Cu)-resistant PGPB from waste water receiving contaminated soil. In addition, we investigated the phytotoxic effect of copper on the lentil plants inoculated with copper-resistant bacteria Providencia vermicola, grown in copper-contaminated soil. Copper-resistant P. vermicola showed multiple plant growth promoting characteristics, when used as a seed inoculant. It protected the lentil plants from copper toxicity with a considerable increase in root and shoot length, plant dry weight and leaf area. A notable increase in different gas exchange characteristics such as A, E, C i , g s , and A/E, as well as increase in N and P accumulation were also recorded in inoculated plants as compared to un-inoculated copper stressed plants. In addition, leaf chlorophyll content, root nodulation, number of pods, 1,000 seed weight were also higher in inoculated plants as compared with non-inoculated ones. Anti-oxidative defense mechanism improved significantly via elevated expression of reactive oxygen species -scavenging enzymes including ascorbate peroxidase, superoxide dismutase, catalase, and guaiacol peroxidase with alternate decrease in malondialdehyde and H2O2 contents, reduced electrolyte leakage, proline, and total phenolic contents suggesting that inoculation of P. vermicola triggered heavy metals stress-related defense pathways under copper stress. Overall, the results demonstrated that the P. vermicola seed inoculation confer heavy metal stress tolerance in lentil plant which can be used as a potent biotechnological tool to cope with the problems of copper pollution in crop plants for better yield. PMID:26387695

  3. Copper-resistant bacteria reduces oxidative stress and uptake of copper in lentil plants: potential for bacterial bioremediation.

    Science.gov (United States)

    Islam, Faisal; Yasmeen, Tahira; Ali, Qasim; Mubin, Muhammad; Ali, Shafaqat; Arif, Muhammad Saleem; Hussain, Sabir; Riaz, Muhammad; Abbas, Farhat

    2016-01-01

    For effective microbe-assisted bioremediation, metal-resistant plant growth-promoting bacteria (PGPB) must facilitate plant growth by restricting excess metal uptake in plants, leading to prevent its bio-amplification in the ecosystem. The aims of our study were to isolate and characterize copper (Cu)-resistant PGPB from waste water receiving contaminated soil. In addition, we investigated the phytotoxic effect of copper on the lentil plants inoculated with copper-resistant bacteria Providencia vermicola, grown in copper-contaminated soil. Copper-resistant P. vermicola showed multiple plant growth promoting characteristics, when used as a seed inoculant. It protected the lentil plants from copper toxicity with a considerable increase in root and shoot length, plant dry weight and leaf area. A notable increase in different gas exchange characteristics such as A, E, C i , g s , and A/E, as well as increase in N and P accumulation were also recorded in inoculated plants as compared to un-inoculated copper stressed plants. In addition, leaf chlorophyll content, root nodulation, number of pods, 1,000 seed weight were also higher in inoculated plants as compared with non-inoculated ones. Anti-oxidative defense mechanism improved significantly via elevated expression of reactive oxygen species -scavenging enzymes including ascorbate peroxidase, superoxide dismutase, catalase, and guaiacol peroxidase with alternate decrease in malondialdehyde and H2O2 contents, reduced electrolyte leakage, proline, and total phenolic contents suggesting that inoculation of P. vermicola triggered heavy metals stress-related defense pathways under copper stress. Overall, the results demonstrated that the P. vermicola seed inoculation confer heavy metal stress tolerance in lentil plant which can be used as a potent biotechnological tool to cope with the problems of copper pollution in crop plants for better yield.

  4. Genetic parameters for rennet- and acid-induced coagulation properties in milk from Swedish Red dairy cows.

    Science.gov (United States)

    Gustavsson, F; Glantz, M; Poulsen, N A; Wadsö, L; Stålhammar, H; Andrén, A; Lindmark Månsson, H; Larsen, L B; Paulsson, M; Fikse, W F

    2014-01-01

    Milk coagulation is an important processing trait, being the basis for production of both cheese and fermented products. There is interest in including technological properties of these products in the breeding goal for dairy cattle. The aim of the present study was therefore to estimate genetic parameters for milk coagulation properties, including both rennet- and acid-induced coagulation, in Swedish Red dairy cattle using genomic relationships. Morning milk samples and blood samples were collected from 395 Swedish Red cows that were selected to be as genetically unrelated as possible. Using a rheometer, milk samples were analyzed for rennet- and acid-induced coagulation properties, including gel strength (G'), coagulation time, and yield stress (YS). In addition to the technological traits, milk composition was analyzed. A binary trait was created to reflect that milk samples that had not coagulated 40min after rennet addition were considered noncoagulating milk. The cows were genotyped by using the Illumina BovineHD BeadChip (Illumina Inc., San Diego, CA). Almost 600,000 markers remained after quality control and were used to construct a matrix of genomic relationships among the cows. Multivariate models including fixed effects of herd, lactation stage, and parity were fitted using the ASReml software to obtain estimates of heritabilities and genetic and phenotypic correlations. Heritability estimates (h(2)) for G' and YS in rennet and acid gels were found to be high (h(2)=0.38-0.62) and the genetic correlations between rennet-induced and acid-induced coagulation properties were weak but favorable, with the exception of YSrennet with G'acid and YSacid, both of which were strong. The high heritability (h(2)=0.45) for milk coagulating ability expressed as a binary trait suggests that noncoagulation could be eliminated through breeding. Additionally, the results indicated that the current breeding objective could increase the frequency of noncoagulating milk and

  5. Improved stress corrosion cracking resistance of a novel biodegradable EW62 magnesium alloy by rapid solidification, in simulated electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Hakimi, O.; Aghion, E. [Department of Materials Engineering, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105 (Israel); Goldman, J., E-mail: jgoldman@mtu.edu [Biomedical Engineering Department, Michigan Technological University, Houghton, MI, 49931 (United States)

    2015-06-01

    The high corrosion rate of magnesium (Mg) and Mg-alloys precludes their widespread acceptance as implantable biomaterials. Here, we investigated the potential for rapid solidification (RS) to increase the stress corrosion cracking (SCC) resistance of a novel Mg alloy, Mg–6%Nd–2%Y–0.5%Zr (EW62), in comparison to its conventionally cast (CC) counterpart. RS ribbons were extrusion consolidated in order to generate bioimplant-relevant geometries for testing and practical use. Microstructural characteristics were examined by SEM. Corrosion rates were calculated based upon hydrogen evolution during immersion testing. The surface layer of the tested alloys was analyzed by X-ray photoelectron spectroscopy (XPS). Stress corrosion resistance was assessed by slow strain rate testing and fractography. The results indicate that the corrosion resistance of the RS alloy is significantly improved relative to the CC alloy due to a supersaturated Nd enrichment that increases the Nd{sub 2}O{sub 3} content in the external oxide layer, as well as a more homogeneous structure and reduced grain size. These improvements contributed to the reduced formation of hydrogen gas and hydrogen embrittlement, which reduced the SCC sensitivity relative to the CC alloy. Therefore, EW62 in the form of a rapidly solidified extruded structure may serve as a biodegradable implant for biomedical applications. - Highlights: • Here we have evaluated the corrosion resistance of a novel Mg alloy (EW62). • Rapid solidification reduces the hydrogen gas evolution and hydrogen embrittlement. • Rapid solidification increases the stress corrosion cracking resistance of EW62. • Improvement is due to enrichment with supersaturated Nd in the external oxide film. • Rapidly solidified and extruded EW62 may serve as a biodegradable medical implant.

  6. Endurance exercise training ameliorates insulin resistance and reticulum stress in adipose and hepatic tissue in obese rats.

    Science.gov (United States)

    da Luz, Gabrielle; Frederico, Marisa J S; da Silva, Sabrina; Vitto, Marcelo F; Cesconetto, Patricia A; de Pinho, Ricardo A; Pauli, José R; Silva, Adelino S R; Cintra, Dennys E; Ropelle, Eduardo R; De Souza, Cláudio T

    2011-09-01

    Obesity-induced endoplasmatic reticulum (ER) stress has been demonstrated to underlie the induction of obesity-induced JNK and NF-κB activation inflammatory responses, and generation of peripheral insulin resistance. On the other hand, exercise has been used as a crucial tool in obese and diabetic patients, and may reduce inflammatory pathway stimulation. However, the ability of exercise training to reverse endoplasmatic reticulum stress in adipose and hepatic tissue in obesity has not been investigated in the literature. Here, we demonstrate that exercise training ameliorates ER stress and insulin resistance in DIO-induced rats. Rats were fed with standard rodent chow (3,948 kcal kg(-1)) or high-fat diet (5,358 kcal kg(-1)) for 2 months. After that rats were submitted to swimming training (1 h per day, 5 days for week with 5% overload of the body weight for 8 weeks). Samples from epididymal fat and liver were obtained and western blot analysis was performed. Our results showed that swimming protocol reduces pro-inflammatory molecules (JNK, IκB and NF-κB) in adipose and hepatic tissues. In addition, exercise leads to reduction in ER stress, by reducing PERK and eIF2α phosphorylation in these tissues. In parallel, an increase in insulin pathway signaling was observed, as confirmed by increases in IR, IRSs and Akt phosphorylation following exercise training in DIO rats. Thus, results suggest that exercise can reduce ER stress, improving insulin resistance in adipose and hepatic tissue. PMID:21249392

  7. Impact of biotic and abiotic stresses on the competitive ability of multiple herbicide resistant wild oat (Avena fatua.

    Directory of Open Access Journals (Sweden)

    Erik A Lehnhoff

    Full Text Available Ecological theory predicts that fitness costs of herbicide resistance should lead to the reduced relative abundance of resistant populations upon the cessation of herbicide use. This greenhouse research investigated the potential fitness costs of two multiple herbicide resistant (MHR wild oat (Avena fatua populations, an economically important weed that affects cereal and pulse crop production in the Northern Great Plains of North America. We compared the competitive ability of two MHR and two herbicide susceptible (HS A. fatua populations along a gradient of biotic and abiotic stresses The biotic stress was imposed by three levels of wheat (Triticum aestivum competition (0, 4, and 8 individuals pot(-1 and an abiotic stress by three nitrogen (N fertilization rates (0, 50 and 100 kg N ha(-1. Data were analyzed with linear mixed-effects models and results showed that the biomass of all A. fatua populations decreased with increasing T. aestivum competition at all N rates. Similarly, A. fatua relative growth rate (RGR decreased with increasing T. aestivum competition at the medium and high N rates but there was no response with 0 N. There were no differences between the levels of biomass or RGR of HS and MHR populations in response to T. aestivum competition. Overall, the results indicate that MHR does not confer growth-related fitness costs in these A. fatua populations, and that their relative abundance will not be diminished with respect to HS populations in the absence of herbicide treatment.

  8. Baicalein modulates stress-resistance and life span in C. elegans via SKN-1 but not DAF-16.

    Science.gov (United States)

    Havermann, Susannah; Humpf, Hans-Ulrich; Wätjen, Wim

    2016-09-01

    The flavonoid baicalein has been demonstrated to be an activator of the transcription factor Nrf2 in mammalian cell lines. We show that it further modulates the Nrf2 homolog SKN-1 in Caenorhabditis elegans and by this pathway mediates beneficial effects in the nematode: baicalein enhances the resistance of C. elegans against lethal thermal and sodium arsenite stress and dose-dependently prolongs the life span of the nematode. Using RNA interference against SKN-1 we were able to show that the induction of longevity and the enhanced stress-resistance were dependent on this transcription factor. DAF-16 (homolog to mammalian FOXO) is another pivotal aging-related transcription factor in the nematode. We demonstrate that DAF-16 does not participate in the beneficial effects of baicalein: since baicalein causes no increase in the nuclear translocation of DAF-16 (DAF-16::GFP expressing strain, incubation time: 1h) and it still induces longevity even in a DAF-16 loss-of-function strain, we conclude, that baicalein increases stress-resistance and life span in C. elegans via SKN-1 but not DAF-16. PMID:27370100

  9. Impact of biotic and abiotic stresses on the competitive ability of multiple herbicide resistant wild oat (Avena fatua).

    Science.gov (United States)

    Lehnhoff, Erik A; Keith, Barbara K; Dyer, William E; Menalled, Fabian D

    2013-01-01

    Ecological theory predicts that fitness costs of herbicide resistance should lead to the reduced relative abundance of resistant populations upon the cessation of herbicide use. This greenhouse research investigated the potential fitness costs of two multiple herbicide resistant (MHR) wild oat (Avena fatua) populations, an economically important weed that affects cereal and pulse crop production in the Northern Great Plains of North America. We compared the competitive ability of two MHR and two herbicide susceptible (HS) A. fatua populations along a gradient of biotic and abiotic stresses The biotic stress was imposed by three levels of wheat (Triticum aestivum) competition (0, 4, and 8 individuals pot(-1)) and an abiotic stress by three nitrogen (N) fertilization rates (0, 50 and 100 kg N ha(-1)). Data were analyzed with linear mixed-effects models and results showed that the biomass of all A. fatua populations decreased with increasing T. aestivum competition at all N rates. Similarly, A. fatua relative growth rate (RGR) decreased with increasing T. aestivum competition at the medium and high N rates but there was no response with 0 N. There were no differences between the levels of biomass or RGR of HS and MHR populations in response to T. aestivum competition. Overall, the results indicate that MHR does not confer growth-related fitness costs in these A. fatua populations, and that their relative abundance will not be diminished with respect to HS populations in the absence of herbicide treatment.

  10. Sarcolemmal dependence of cardiac protection and stress-resistance: roles in aged or diseased hearts.

    Science.gov (United States)

    See Hoe, Louise E; May, Lauren T; Headrick, John P; Peart, Jason N

    2016-10-01

    Disruption of the sarcolemmal membrane is a defining feature of oncotic death in cardiac ischaemia-reperfusion (I-R), and its molecular makeup not only fundamentally governs this process but also affects multiple determinants of both myocardial I-R injury and responsiveness to cardioprotective stimuli. Beyond the influences of membrane lipids on the cytoprotective (and death) receptors intimately embedded within this bilayer, myocardial ionic homeostasis, substrate metabolism, intercellular communication and electrical conduction are all sensitive to sarcolemmal makeup, and critical to outcomes from I-R. As will be outlined in this review, these crucial sarcolemmal dependencies may underlie not only the negative effects of age and common co-morbidities on myocardial ischaemic tolerance but also the on-going challenge of implementing efficacious cardioprotection in patients suffering accidental or surgically induced I-R. We review evidence for the involvement of sarcolemmal makeup changes in the impairment of stress-resistance and cardioprotection observed with ageing and highly prevalent co-morbid conditions including diabetes and hypercholesterolaemia. A greater understanding of membrane changes with age/disease, and the inter-dependences of ischaemic tolerance and cardioprotection on sarcolemmal makeup, can facilitate the development of strategies to preserve membrane integrity and cell viability, and advance the challenging goal of implementing efficacious 'cardioprotection' in clinically relevant patient cohorts. Linked Articles This article is part of a themed section on Molecular Pharmacology of G Protein-Coupled Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.20/issuetoc.

  11. Sida rhomboidea.Roxb extract alleviates pathophysiological changes in experimental in vivo and in vitro models of high fat diet/fatty acid induced non-alcoholic steatohepatitis.

    Science.gov (United States)

    Thounaojam, Menaka C; Jadeja, Ravirajsinh N; Dandekar, Deven S; Devkar, Ranjitsinh V; Ramachandran, A V

    2012-03-01

    The present study was aim to evaluate protective role of Sida rhomboidea.Roxb (SR) extract against high fat diet/fatty acid induced pathophysiological alterations in experimental model of non-alcoholic steatohepatitis (NASH). Effect of SR extract on plasma levels of markers of hepatic damage, plasma and hepatic lipids, mitochondrial oxidative stress, status of enzymatic and non-enzymatic antioxidants and histopathological changes in liver tissue were evaluated in high fat diet fed C57BL/6J mice. Also, the effect of SR supplementation on lipid accumulation, lipid peroxidation, cytotoxicity and cell viability were evaluated in oleic acid treated HepG2 cells. Supplementation of NASH mice with SR extract prevented high fat diet induced elevation in plasma marker enzymes of liver damage, plasma and hepatic lipids, mitochondrial oxidative stress and compromised enzymatic and non-enzymatic antioxidant status. Further, addition of SR extract to in vitro HepG2 cells minimized oleic acid induced lipid accumulation, higher lipid peroxidation, cytotoxicity and reduced cell viability. These in vivo and in vitro studies suggest that SR extract has the potential of preventing high fat/fatty acid induced NASH mainly due to its hypolipidemic and antioxidant activities.

  12. Resistência ao Estresse Calórico em Frangos de Corte de Pescoço Pelado Resistance to Heat Stress of Naked Neck Broilers

    Directory of Open Access Journals (Sweden)

    MAN Silva

    2001-01-01

    Full Text Available Aves de duas linhagens, sendo uma portadora do gene pescoço pelado (Na_ que determina redução no empenamento, e outra não portadora, com empenamento normal (nana, foram submetidas a estresse térmico gradativo (38, 40 e 42ºC, em câmara climática, nas idades de 28, 35 e 42 dias, com o intuito de se verificar a resistência ao estresse térmico. Foram verificadas diferenças significativas entre a temperatura retal média e a taxa respiratória média da linhagem de empenamento normal quando comparada com a linhagem de pescoço pelado, em todas as idades e períodos de estresse. Foram verificados valores mais altos das aves de empenamento normal, demonstrando a influência do conjunto temperatura de estresse térmico e idade. Pôde-se constatar que houve diferença significativa entre as linhagens para as médias de perda de peso apenas aos 35 dias de idade. Os resultados obtidos sugerem que a linhagem de pescoço pelado (Na_ possui maior resistência ao estresse térmico em relação à linhagem de empenamento normal (nana.Birds of two lineages, a carrier of the Naked Neck gene (Na_ that determines reduction in the feathering and other non-carrier (normal feathering, nana, were submitted to thermal stress (38, 40 and 42ºC in climatic chambers at 28, 35 and 42 days of age to verify the resistance to the thermal stress. Significant differences were verified among the mean rectal temperature of the normal feathered lineage when compared with the naked neck lineage, in all the ages and stress periods, with higher values in the normal feathered birds. The same result was found for mean respiratory rate. Significant difference was found for weight loss between the two lineages only at the age of 35 days. The results obtained suggest that the Naked Neck lineage possesses higher resistance to the thermal stress in relation to the normal feathered lineage.

  13. Effect of tensile stress on the in-plane resistivity anisotropy in BaFe2As2

    International Nuclear Information System (INIS)

    The effect of uniaxial tensile stress and the resultant strain on the structural/magnetic transition in the parent compound of the iron arsenide superconductor BaFe2As2 is characterized by temperature-dependent electrical resistivity, x-ray diffraction, and quantitative polarized light imaging. We show that strain induces a measurable uniaxial structural distortion above the first-order magnetic transition and significantly smears the structural transition. This response is different from that found in another parent compound, SrFe2As2, where the coupled structural and magnetic transitions are strongly first order. This difference in the structural responses explains the in-plane resistivity anisotropy above the transition in BaFe2As2. This conclusion is supported by the Ginzburg-Landau-type phenomenological model for the effect of the uniaxial strain on the resistivity anisotropy.

  14. Theoretical Research on Thermal Shock Resistance of Ultra-High Temperature Ceramics Focusing on the Adjustment of Stress Reduction Factor

    Directory of Open Access Journals (Sweden)

    Daining Fang

    2013-02-01

    Full Text Available The thermal shock resistance of ceramics depends on not only the mechanical and thermal properties of materials, but also the external constraint and thermal condition. So, in order to study the actual situation in its service process, a temperature-dependent thermal shock resistance model for ultra-high temperature ceramics considering the effects of the thermal environment and external constraint was established based on the existing theory. The present work mainly focused on the adjustment of the stress reduction factor according to different thermal shock situations. The influences of external constraint on both critical rupture temperature difference and the second thermal shock resistance parameter in either case of rapid heating or cooling conditions had been studied based on this model. The results show the necessity of adjustment of the stress reduction factor in different thermal shock situations and the limitations of the applicable range of the second thermal shock resistance parameter. Furthermore, the model was validated by the finite element method.

  15. Loss of Oca2 disrupts the unfolded protein response and increases resistance to endoplasmic reticulum stress in melanocytes.

    Science.gov (United States)

    Cheng, Tsing; Orlow, Seth J; Manga, Prashiela

    2013-11-01

    Accumulation of proteins in the endoplasmic reticulum (ER) typically induces stress and initiates the unfolded protein response (UPR) to facilitate recovery. If homeostasis is not restored, apoptosis is induced. However, adaptation to chronic UPR activation can increase resistance to subsequent acute ER stress. We therefore investigated adaptive mechanisms in Oculocutaneous albinism type 2 (Oca2)-null melanocytes where UPR signaling is arrested despite continued tyrosinase accumulation leading to resistance to the chemical ER stressor thapsigargin. Although thapsigargin triggers UPR activation, instead of Perk-mediated phosphorylation of eIF2α, in Oca2-null melanocytes, eIF2α was rapidly dephosphorylated upon treatment. Dephosphorylation was mediated by the Gadd34-PP1α phosphatase complex. Gadd34-complex inhibition blocked eIF2α dephosphorylation and significantly increased Oca2-null melanocyte sensitivity to thapsigargin. Thus, Oca2-null melanocytes adapt to acute ER stress by disruption of pro-apoptotic Perk signaling, which promotes cell survival. This is the first study to demonstrate rapid eIF2α dephosphorylation as an adaptive mechanism to ER stress.

  16. Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Woolbright, Benjamin L.; Dorko, Kenneth [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Antoine, Daniel J.; Clarke, Joanna I. [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Gholami, Parviz [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Li, Feng [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Kumer, Sean C.; Schmitt, Timothy M.; Forster, Jameson [Department of Surgery, University of Kansas Medical Center, Kansas City, KS (United States); Fan, Fang [Department of Pathology, University of Kansas Medical Center, Kansas City, KS (United States); Jenkins, Rosalind E.; Park, B. Kevin [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Hagenbuch, Bruno [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Olyaee, Mojtaba [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2015-03-15

    Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models. - Highlights: • Cholestatic liver injury is due to cytoplasmic bile acid accumulation in hepatocytes. • Primary human hepatocytes are resistant to BA-induced injury

  17. Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis

    International Nuclear Information System (INIS)

    Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models. - Highlights: • Cholestatic liver injury is due to cytoplasmic bile acid accumulation in hepatocytes. • Primary human hepatocytes are resistant to BA-induced injury

  18. The Multifunctional PE_PGRS11 Protein from Mycobacterium tuberculosis Plays a Role in Regulating Resistance to Oxidative Stress*

    Science.gov (United States)

    Chaturvedi, Rashmi; Bansal, Kushagra; Narayana, Yeddula; Kapoor, Nisha; Sukumar, Namineni; Togarsimalemath, Shambhuprasad Kotresh; Chandra, Nagasuma; Mishra, Saurabh; Ajitkumar, Parthasarathi; Joshi, Beenu; Katoch, Vishwa Mohan; Patil, Shripad A.; Balaji, Kithiganahalli N.

    2010-01-01

    Mycobacterium tuberculosis utilizes unique strategies to survive amid the hostile environment of infected host cells. Infection-specific expression of a unique mycobacterial cell surface antigen that could modulate key signaling cascades can act as a key survival strategy in curtailing host effector responses like oxidative stress. We demonstrate here that hypothetical PE_PGRS11 ORF encodes a functional phosphoglycerate mutase. The transcriptional analysis revealed that PE_PGRS11 is a hypoxia-responsive gene, and enforced expression of PE_PGRS11 by recombinant adenovirus or Mycobacterium smegmatis imparted resistance to alveolar epithelial cells against oxidative stress. PE_PGRS11-induced resistance to oxidative stress necessitated the modulation of genetic signatures like induced expression of Bcl2 or COX-2. This modulation of specific antiapoptotic molecular signatures involved recognition of PE_PGRS11 by TLR2 and subsequent activation of the PI3K-ERK1/2-NF-κB signaling axis. Furthermore, PE_PGRS11 markedly diminished H2O2-induced p38 MAPK activation. Interestingly, PE_PGRS11 protein was exposed at the mycobacterial cell surface and was involved in survival of mycobacteria under oxidative stress. Furthermore, PE_PGRS11 displayed differential B cell responses during tuberculosis infection. Taken together, our investigation identified PE_PGRS11 as an in vivo expressed immunodominant antigen that plays a crucial role in modulating cellular life span restrictions imposed during oxidative stress by triggering TLR2-dependent expression of COX-2 and Bcl2. These observations clearly provide a mechanistic basis for the rescue of pathogenic Mycobacterium-infected lung epithelial cells from oxidative stress. PMID:20558725

  19. Activation of PPARα ameliorates hepatic insulin resistance and steatosis in high fructose-fed mice despite increased endoplasmic reticulum stress.

    Science.gov (United States)

    Chan, Stanley M H; Sun, Ruo-Qiong; Zeng, Xiao-Yi; Choong, Zi-Heng; Wang, Hao; Watt, Matthew J; Ye, Ji-Ming

    2013-06-01

    Endoplasmic reticulum (ER) stress is suggested to cause hepatic insulin resistance by increasing de novo lipogenesis (DNL) and directly interfering with insulin signaling through the activation of the c-Jun N-terminal kinase (JNK) and IκB kinase (IKK) pathway. The current study interrogated these two proposed mechanisms in a mouse model of hepatic insulin resistance induced by a high fructose (HFru) diet with the treatment of fenofibrate (FB) 100 mg/kg/day, a peroxisome proliferator-activated receptor α (PPARα) agonist known to reduce lipid accumulation while maintaining elevated DNL in the liver. FB administration completely corrected HFru-induced glucose intolerance, hepatic steatosis, and the impaired hepatic insulin signaling (pAkt and pGSK3β). Of note, both the IRE1/XBP1 and PERK/eIF2α arms of unfolded protein response (UPR) signaling were activated. While retaining the elevated DNL (indicated by the upregulation of SREBP1c, ACC, FAS, and SCD1 and [3H]H2O incorporation into lipids), FB treatment markedly increased fatty acid oxidation (indicated by induction of ACOX1, p-ACC, β-HAD activity, and [14C]palmitate oxidation) and eliminated the accumulation of diacylglycerols (DAGs), which is known to have an impact on insulin signaling. Despite the marked activation of UPR signaling, neither JNK nor IKK appeared to be activated. These findings suggest that lipid accumulation (mainly DAGs), rather than the activation of JNK or IKK, is pivotal for ER stress to cause hepatic insulin resistance. Therefore, by reducing the accumulation of deleterious lipids, activation of PPARα can ameliorate hepatic insulin resistance against increased ER stress.

  20. An experimental approach to assess Corbicula fluminea (Müller, 1774) resistance to osmotic stress in estuarine habitats

    Science.gov (United States)

    Ferreira-Rodríguez, Noé; Pardo, Isabel

    2016-07-01

    Corbicula fluminea arrived in the Miño Estuary in 1989 and, from there, colonized more than 150 km upstream. Our aim was to test the capacity of C. fluminea to cope with osmotic stress conditions previously to invade new freshwater habitats through estuaries. Based on previously collected information, the experiment aims to study the response of the species to marine osmotic stress, evaluated by survival and behaviour. Experiments determined the resistance by the species to various levels of osmotic stress, and recovery time after exposure to high salinity levels, representative of the temporal and spatial salinity variation existing in the estuary. Under osmotic stress the semi-maximum response was reached after 19 days exposure. The species tolerance range, measured by individual maintained activity, was at salinity ∼20 when exposed to winter temperatures, while when animals were exposed to summer ones its tolerance was reduced to salinity lower than 15. C. fluminea show a large physiological flexibility to cope with salinity variations in estuaries. In summer, the temperature increases the metabolic rate thus making the species more vulnerable to osmotic stress exposure. These findings are relevant to preventing new invasions through ship ballast waters ensuring complete mortality if individuals are retained for >26 days.

  1. On Residual Stresses in Resistance Spot-Welded Aluminum Alloy 6061-T6: Experimental and Numerical Analysis

    Science.gov (United States)

    Afshari, D.; Sedighi, M.; Karimi, M. R.; Barsoum, Z.

    2013-12-01

    In this study, an electro-thermal-structural-coupled finite element (FE) model and x-ray diffraction residual stress measurements have been utilized to analyze distribution of residual stresses in an aluminum alloy 6061-T6 resistance spot-welded joint with 2-mm-thickness sheet. Increasing the aluminum sheet thickness to more than 1 mm leads to creating difficulty in spot-welding process and increases the complexity of the FE model. The electrical and thermal contact conductances, as mandatory factors are applied in contact areas of electrode-workpiece and workpiece-workpiece to resolve the complexity of the FE model. The physical and mechanical properties of the material are defined as thermal dependent to improve the accuracy of the model. Furthermore, the electrodes are removed after the holding cycle using the birth-and-death elements method. The results have a good agreement with experimental data obtained from x-ray diffraction residual stress measurements. However, the highest internal tensile residual stress occurs in the center of the nugget zone and decreases toward nugget edge; surface residual stress increases toward the edge of the welding zone and afterward, the area decreases slightly.

  2. Constitutive production of nitric oxide leads to enhanced drought stress resistance and extensive transcriptional reprogramming in Arabidopsis.

    Science.gov (United States)

    Shi, Haitao; Ye, Tiantian; Zhu, Jian-Kang; Chan, Zhulong

    2014-08-01

    Nitric oxide (NO) is involved in plant responses to many environmental stresses. Transgenic Arabidopsis lines that constitutively express rat neuronal NO synthase (nNOS) were described recently. In this study, it is reported that the nNOS transgenic Arabidopsis plants displayed high levels of osmolytes and increased antioxidant enzyme activities. Transcriptomic analysis identified 601 or 510 genes that were differentially expressed as a consequence of drought stress or nNOS transformation, respectively. Pathway and gene ontology (GO) term enrichment analyses revealed that genes involved in photosynthesis, redox, stress, and phytohormone and secondary metabolism were greatly affected by the nNOS transgene. Several CBF genes and members of zinc finger gene families, which are known to regulate transcription in the stress response, were changed by the nNOS transgene. Genes regulated by both the nNOS transgene and abscisic acid (ABA) treatments were compared and identified, including those for two ABA receptors (AtPYL4 and AtPYL5). Moreover, overexpression of AtPYL4 and AtPYL5 enhanced drought resistance, antioxidant enzyme activity, and osmolyte levels. These observations increase our understanding of the role of NO in drought stress response in Arabidopsis. PMID:24868034

  3. Analysis of Salicylic Acid Induced Proteins in Rice

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    An analysis using SDS-PAGE of acidic and basic protein fractions extracted from rice seedling treated with salicylic acid (SA) yielded several new proteins, some of which are similar in relative molecular mass to PR-1a,c, PR-2, 2e and PR-3d, 3e of tobacco.Direct assays for peroxidases and β-1,3-glucanases demonstrated that the activities of the two enzymes in the rice seedlings increased rapidly with time after SA treatment, reaching a maximum 6 days after treatment.Disease resistance tests showed that SA treated rice seedlings stunted the development of blight lesions and displayed higher resistance to rice blight pathogen (Xanthomonas oryzea pv.oryzea).The data suggest that the treatment with SA, even for plants with high endogenous SA levels such as rice, may induce the appearance of new proteins and the formation of disease resistance.The results contribute to the analysis of the SA role in rice systemic acquired resistance.

  4. Advances in plant proteomics towards improvement of crop productivity and stress resistance

    Directory of Open Access Journals (Sweden)

    Junjie eHu

    2015-04-01

    Full Text Available Abiotic and biotic stresses constrain plant growth and development negatively impacting crop production. Plants have developed stress-specific adaptations as well as simultaneous responses to a combination of various abiotic stresses with pathogen infection. The efficiency of stress-induced adaptive responses is dependent on activation of molecular signaling pathways and intracellular networks by modulating expression, or abundance, and/or posttranslational modification of proteins primarily associated with defense mechanisms. In this review, we summarize and evaluate the contribution of proteomic studies to our understanding of stress response mechanisms in different plant organs and tissues. Advanced quantitative proteomic techniques have improved the coverage of total proteomes and sub-proteomes from small amounts of starting material, and characterized post-translational modifications as well as protein–protein interactions at the cellular level, providing detailed information on organ- and tissue-specific regulatory mechanisms responding to a variety of individual stresses or stress combinations during plant life cycle. In particular, we address the tissue-specific signaling networks localized to various organelles that participate in stress-related physiological plasticity and adaptive mechanisms, such as photosynthetic efficiency, symbiotic nitrogen fixation, plant growth, tolerance and common responses to environmental stresses. We also provide an update on the progress of proteomics with major crop species and discuss the current challenges and limitations inherent to proteomics techniques and data interpretation for non-model organisms. Future directions in proteomics research towards crop improvement are further discussed.

  5. The Role of Oxidative Stress in the Longevity and Insecticide Resistance Phenotype of the Major Malaria Vectors Anopheles arabiensis and Anopheles funestus.

    Directory of Open Access Journals (Sweden)

    Shüné V Oliver

    Full Text Available Oxidative stress plays numerous biological roles, both functional and pathological. The role of oxidative stress in various epidemiologically relevant biological traits in Anopheles mosquitoes is not well established. In this study, the effects of oxidative stress on the longevity and insecticide resistance phenotype in the major malaria vector species An. arabiensis and An. funestus were examined. Responses to dietary copper sulphate and hydrogen peroxide were used as proxies for the oxidative stress phenotype by determining the effect of copper on longevity and hydrogen peroxide lethal dose. Glutathione peroxidase and catalase activities were determined colorimetrically. Oxidative burden was quantified as protein carbonyl content. Changes in insecticide resistance phenotype were monitored by WHO bioassay. Insecticide resistant individuals showed an increased capacity for coping with oxidative stress, mediated by increased glutathione peroxidase and catalase activity. This effect was observed in both species, as well as in laboratory strains and F1 individuals derived from wild-caught An. funestus mothers. Phenotypic capacity for coping with oxidative stress was greatest in strains with elevated Cytochrome P450 activity. Synergism of oxidative stress defence enzymes by dietary supplementation with haematin, 3-Amino-1, 2, 4-triazole and Sodium diethyldithiocarbamate significantly increased pyrethroid-induced mortality in An. arabiensis and An. funestus. It is therefore concluded that defence against oxidative stress underlies the augmentation of the insecticide resistance phenotype associated with multiple blood-feeding. This is because multiple blood-feeding ultimately leads to a reduction of oxidative stress in insecticide resistant females, and also reduces the oxidative burden induced by DDT and pyrethroids, by inducing increased glutathione peroxidase activity. This study highlights the importance of oxidative stress in the longevity and

  6. Alpha-lipoic acid attenuates endoplasmic reticulum stress-induced insulin resistance by improving mitochondrial function in HepG2 cells.

    Science.gov (United States)

    Lei, Lin; Zhu, Yiwei; Gao, Wenwen; Du, Xiliang; Zhang, Min; Peng, Zhicheng; Fu, Shoupeng; Li, Xiaobing; Zhe, Wang; Li, Xinwei; Liu, Guowen

    2016-10-01

    Alpha-lipoic acid (ALA) has been reported to have beneficial effects for improving insulin sensitivity. However, the underlying molecular mechanism of the beneficial effects remains poorly understood. Endoplasmic reticulum (ER) stress and mitochondrial dysfunction are considered causal factors that induce insulin resistance. In this study, we investigated the effect of ALA on the modulation of insulin resistance in ER-stressed HepG2 cells, and we explored the potential mechanism of this effect. HepG2 cells were incubated with tunicamycin (Tun) for 6h to establish an ER stress cell model. Tun treatment induced ER stress, mitochondrial dysfunction and insulin resistance. Interestingly, ALA had no significant effect on ER stress signals. Pretreatment of the ER stress cell model with ALA for 24h improved insulin sensitivity, restored the expression levels of mitochondrial oxidative phosphorylation (OXPHOS) complexes and increased intracellular ATP production. Moreover, ALA augmented the β-oxidation capacity of the mitochondria. Importantly, ALA treatment could decrease oligomycin-induced mitochondrial dysfunction and then improved insulin resistance. Taken together, our data suggest that ALA prevents ER stress-induced insulin resistance by enhancing mitochondrial function. PMID:27377964

  7. Improved stress corrosion cracking resistance of a novel biodegradable EW62 magnesium alloy by rapid solidification, in simulated electrolytes.

    Science.gov (United States)

    Hakimi, O; Aghion, E; Goldman, J

    2015-06-01

    The high corrosion rate of magnesium (Mg) and Mg-alloys precludes their widespread acceptance as implantable biomaterials. Here, we investigated the potential for rapid solidification (RS) to increase the stress corrosion cracking (SCC) resistance of a novel Mg alloy, Mg-6%Nd-2%Y-0.5%Zr (EW62), in comparison to its conventionally cast (CC) counterpart. RS ribbons were extrusion consolidated in order to generate bioimplant-relevant geometries for testing and practical use. Microstructural characteristics were examined by SEM. Corrosion rates were calculated based upon hydrogen evolution during immersion testing. The surface layer of the tested alloys was analyzed by X-ray photoelectron spectroscopy (XPS). Stress corrosion resistance was assessed by slow strain rate testing and fractography. The results indicate that the corrosion resistance of the RS alloy is significantly improved relative to the CC alloy due to a supersaturated Nd enrichment that increases the Nd2O3 content in the external oxide layer, as well as a more homogeneous structure and reduced grain size. These improvements contributed to the reduced formation of hydrogen gas and hydrogen embrittlement, which reduced the SCC sensitivity relative to the CC alloy. Therefore, EW62 in the form of a rapidly solidified extruded structure may serve as a biodegradable implant for biomedical applications.

  8. A role for sigma factor SigE in Corynebacterium pseudotuberculosis resistance to nitric oxide/ peroxide stress

    Directory of Open Access Journals (Sweden)

    Luis G. C. Pacheco

    2012-04-01

    Full Text Available Pathogenic intracellular bacteria can respond to antimicrobial mechanisms of the host cell through transient activation of stress-responsive genes by alternative sigma (σ factors of the RNA polymerase. We evaluated the contribution of the extracytoplasmic function sigma factor σE for Corynebacterium pseudotuberculosis resistance to stress conditions resembling those found intracellularly during infection. A sigE null mutant strain (delta-sigE of this bacterium was more susceptible in vitro to acidic pH, cell surface stressors, and biologically relevant concentrations of nitric oxide (NO. The same mutant strain was unable to persist in C57BL/6 mice but remained infective in mice lacking inducible nitric oxide synthase (iNOS, confirming the significance of σE for resistance to nitric oxide/peroxide stress in vivo. High-throughput proteomic analysis identified NO-responsive extracellular proteins of C. pseudotuberculosis and demonstrated the participation of σE in composition of this bacterium´s exoproteome.

  9. A novel role for the SMG-1 kinase in lifespan and oxidative stress resistance in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Ingrid Masse

    Full Text Available The PTEN tumour suppressor encodes a phosphatase, and its daf-18 orthologue in Caenorhabditis elegans negatively regulates the insulin/IGF-1 DAF-2 receptor pathway that influences lifespan in worms and other species. In order to identify new DAF-18 regulated pathways involved in aging, we initiated a candidate RNAi feeding screen for clones that lengthen lifespan. Here, we report that smg-1 inactivation increases average lifespan in a daf-18 dependent manner. Genetic analysis is consistent with SMG-1 acting at least in part in parallel to the canonical DAF-2 receptor pathway, but converging on the transcription factor DAF-16/FOXO. SMG-1 is a serine-threonine kinase which plays a conserved role in nonsense-mediated mRNA decay (NMD in worms and mammals. In addition, human SMG-1 has also been implicated in the p53-mediated response to genotoxic stress. The effect of smg-1 inactivation on lifespan appears to be unrelated to its NMD function, but requires the p53 tumour suppressor orthologue cep-1. Furthermore, smg-1 inactivation confers a resistance to oxidative stress in a daf-18-, daf-16- and cep-1-dependent manner. We propose that the role of SMG-1 in lifespan regulation is at least partly dependent on its function in oxidative stress resistance. Taken together, our results unveil a novel role for SMG-1 in lifespan regulation.

  10. Nitric Oxide Involved in the Abscisic Acid Induced Proline Accumulation in Wheat Seedling Leaves Under Salt Stress%一氧化氮参与调节盐胁迫下脱落酸诱导的小麦幼苗叶片脯氨酸的累积

    Institute of Scientific and Technical Information of China (English)

    阮海华; 沈文飚; 徐朗莱

    2004-01-01

    Exogenous nitric oxide (NO) releaser sodium nitroprusside (SNP) with different concentrations from 0.01 to 5.00 mmol/L induced proline accumulation in wheat ( Triticum aestivum L. cv. Yangmai 158) seedling leaves under 150 mmol/L salt stress in a dose-dependent manner. It was most effective at 0.1 mmol/L SNP, and the combination treatments with two NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) and hemoglobin, separately reverted the 0.1 mmol/L SNP induced proline accumulation. Meanwhile, the proline accumulation induced by NO might be of benefit to the water retention in wheat seedling leaves when subjected to salinity, and exogenous 0.1 mmol/L SNP treatment also dramatically activated the synthesis of endogenous abscisic acid (ABA), and the employment of hemoglobin further indicated that NO might be downstream of the ABA induced proline accumulation in wheat seedling leaves under 150 mmol/L salt stress, but there did not exist synergism between NO and ABA signaling toward proline accumulation. Detection of proline synthesis and degradation demonstrated that exogenous NO induced proline accumulation in a phase dependent manner, mainly by enhancing the activities of △1-pyrroline-5-carboxylate synthetase (PSCS) within the first 4 d of treatment and inhibiting activities of proline dehydrogenase (ProDH) 4 d later up to 8 d. And ABA showed a weak effect on PSCS and ProDH activities in comparison with NO treatment. Additionally, Ca2+ was confirmed as the important intermediates during the NO signaling pathway in proline accumulation under salinity conditions.%不同浓度(0.01~5.00mmol/L)的外源一氧化氮(NO)供体硝普钠(SNP)以浓度依赖性的性式诱导150mmol/LNaCl胁迫下小麦(Triticum aestivum L.cv.Yangmai 158)幼苗叶片脯氨酸的累积.其中0.1 mmol/L的SNP效果最明显,而结合采用NO清除剂c-PTIO和血红蛋白的处理均分别逆转了该效应.研究结果还发现:0.1 mmol/L SNP诱导的

  11. Staphylococcus aureus ClpC is required for stress resistance, aconitase activity, growth recovery, and death

    NARCIS (Netherlands)

    Chatterjee, Indranil; Becker, Petra; Grundmeier, Matthias; Bischoff, Markus; Somerville, Greg A; Peters, Georg; Sinha, Bhanu; Harraghy, Niamh; Proctor, Richard A; Herrmann, Mathias

    2005-01-01

    The ability of Staphylococcus aureus to adapt to various conditions of stress is the result of a complex regulatory response. Previously, it has been demonstrated that Clp homologues are important for a variety of stress conditions, and our laboratory has shown that a clpC homologue was highly expre

  12. Stress

    Science.gov (United States)

    ... Some people experience digestive symptoms. Others may have headaches, sleeplessness, depressed mood, anger, and irritability. People under chronic stress get more frequent and severe viral infections, such ...

  13. Low Temperature-Induced 30 (LTI30 positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation

    Directory of Open Access Journals (Sweden)

    Haitao eShi

    2015-10-01

    Full Text Available As a dehydrin belonging to group II late embryogenesis abundant protein (LEA family, Arabidopsis Low Temperature-Induced 30 (LTI30/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT. Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2 accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation.

  14. Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation.

    Science.gov (United States)

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible involvement of AtLTI30 in ABA and drought stress responses. AtLTI30 knockout mutants were less sensitive to ABA-mediated seed germination, while AtLTI30 overexpressing plants were more sensitive to ABA compared with wild type (WT). Consistently, the AtLTI30 knockout mutants displayed decreased drought stress resistance, while the AtLTI30 overexpressing plants showed improved drought stress resistance compared with WT, as evidenced by a higher survival rate and lower leaf water loss than WT after drought stress. Moreover, manipulation of AtLTI30 expression positively regulated the activities of catalases (CATs) and endogenous proline content, as a result, negatively regulated drought stress-triggered hydrogen peroxide (H2O2) accumulation. All these results indicate that AtLTI30 is a positive regulator of plant drought stress resistance, partially through the modulation of ABA sensitivity, H2O2 and proline accumulation. PMID:26539205

  15. Valproic acid induces antimicrobial compound production in Doratomyces microspores.

    Directory of Open Access Journals (Sweden)

    Christoph eZutz

    2016-04-01

    Full Text Available One of the biggest challenges in public health is the rising number of antibiotic resistant pathogens and the lack of novel antibiotics. In recent years there is a rising focus on fungi as sources of antimicrobial compounds due to their ability to produce a large variety of bioactive compounds and the observation that virtually every fungus may still contain yet unknown so called cryptic, often silenced, compounds. These putative metabolites could include novel bioactive compounds. Considerable effort is spent on methods to induce production of these cryptic metabolites. One approach is the use of small molecule effectors, potentially influencing chromatin landscape in fungi. We observed that the supernatant of the fungus Doratomyces (D. microsporus treated with valproic acid (VPA displayed antimicrobial activity against Staphylococcus (S. aureus and two methicillin resistant clinical S. aureus isolates. VPA treatment resulted in enhanced production of seven antimicrobial compounds: cyclo-(L-proline-L-methionine (cPM, p-hydroxybenzaldehyde, cyclo-(phenylalanine-proline (cFP, indole-3-carboxylic acid, phenylacetic acid (PAA and indole-3-acetic acid. The production of the antimicrobial compound phenyllactic acid was exclusively detectable after VPA treatment. Furthermore three compounds, cPM, cFP and PAA, were able to boost the antimicrobial activity of other antimicrobial compounds. cPM, for the first time isolated from fungi, and to a lesser extent PAA, are even able to decrease the minimal inhibitory concentration of ampicillin in MRSA strains. In conclusion we could show in this study that VPA treatment is a potent tool for induction of cryptic antimicrobial compound production in fungi, and that the induced compounds are not exclusively linked to the secondary metabolism. Furthermore this is the first discovery of the rare diketopiperazine cPM in fungi. Additionally we could demonstrate that cPM and PAA boost antibiotic activity against

  16. Valproic Acid Induces Antimicrobial Compound Production in Doratomyces microspores

    Science.gov (United States)

    Zutz, Christoph; Bacher, Markus; Parich, Alexandra; Kluger, Bernhard; Gacek-Matthews, Agnieszka; Schuhmacher, Rainer; Wagner, Martin; Rychli, Kathrin; Strauss, Joseph

    2016-01-01

    One of the biggest challenges in public health is the rising number of antibiotic resistant pathogens and the lack of novel antibiotics. In recent years there is a rising focus on fungi as sources of antimicrobial compounds due to their ability to produce a large variety of bioactive compounds and the observation that virtually every fungus may still contain yet unknown so called “cryptic,” often silenced, compounds. These putative metabolites could include novel bioactive compounds. Considerable effort is spent on methods to induce production of these “cryptic” metabolites. One approach is the use of small molecule effectors, potentially influencing chromatin landscape in fungi. We observed that the supernatant of the fungus Doratomyces (D.) microsporus treated with valproic acid (VPA) displayed antimicrobial activity against Staphylococcus (S.) aureus and two methicillin resistant clinical S. aureus isolates. VPA treatment resulted in enhanced production of seven antimicrobial compounds: cyclo-(L-proline-L-methionine) (cPM), p-hydroxybenzaldehyde, cyclo-(phenylalanine-proline) (cFP), indole-3-carboxylic acid, phenylacetic acid (PAA) and indole-3-acetic acid. The production of the antimicrobial compound phenyllactic acid was exclusively detectable after VPA treatment. Furthermore three compounds, cPM, cFP, and PAA, were able to boost the antimicrobial activity of other antimicrobial compounds. cPM, for the first time isolated from fungi, and to a lesser extent PAA, are even able to decrease the minimal inhibitory concentration of ampicillin in MRSA strains. In conclusion we could show in this study that VPA treatment is a potent tool for induction of “cryptic” antimicrobial compound production in fungi, and that the induced compounds are not exclusively linked to the secondary metabolism. Furthermore this is the first discovery of the rare diketopiperazine cPM in fungi. Additionally we could demonstrate that cPM and PAA boost antibiotic activity

  17. Inhibition of ceramide synthesis ameliorates glucocorticoid-, saturated-fat-, and obesity-induced insulin resistance.

    Science.gov (United States)

    Holland, William L; Brozinick, Joseph T; Wang, Li-Ping; Hawkins, Eric D; Sargent, Katherine M; Liu, Yanqi; Narra, Krishna; Hoehn, Kyle L; Knotts, Trina A; Siesky, Angela; Nelson, Don H; Karathanasis, Sotirios K; Fontenot, Greg K; Birnbaum, Morris J; Summers, Scott A

    2007-03-01

    Insulin resistance occurs in 20%-25% of the human population, and the condition is a chief component of type 2 diabetes mellitus and a risk factor for cardiovascular disease and certain forms of cancer. Herein, we demonstrate that the sphingolipid ceramide is a common molecular intermediate linking several different pathological metabolic stresses (i.e., glucocorticoids and saturated fats, but not unsaturated fats) to the induction of insulin resistance. Moreover, inhibition of ceramide synthesis markedly improves glucose tolerance and prevents the onset of frank diabetes in obese rodents. Collectively, these data have two important implications. First, they indicate that different fatty acids induce insulin resistance by distinct mechanisms discerned by their reliance on sphingolipid synthesis. Second, they identify enzymes required for ceramide synthesis as therapeutic targets for combating insulin resistance caused by nutrient excess or glucocorticoid therapy.

  18. Nose-only water-pipe smoking effects on airway resistance, inflammation, and oxidative stress in mice.

    Science.gov (United States)

    Nemmar, Abderrahim; Raza, Haider; Yuvaraju, Priya; Beegam, Sumaya; John, Annie; Yasin, Javed; Hameed, Rasheed S; Adeghate, Ernest; Ali, Badreldin H

    2013-11-01

    Water-pipe smoking (WPS) is a common practice in the Middle East and is now gaining popularity in Europe and the United States. However, there is a limited number of studies on the respiratory effects of WPS. More specifically, the underlying pulmonary pathophysiological mechanisms related to WPS exposure are not understood. Presently, we assessed the respiratory effects of nose-only exposure to mainstream WPS generated by commercially available honey flavored "moasel" tobacco. The duration of the session was 30 min/day and 5 days/wk for 1 mo. Control mice were exposed to air only. Here, we measured in BALB/c mice the airway resistance using forced-oscillation technique. Lung inflammation was assessed histopathologically and by biochemical analysis of bronchoalveolar lavage (BAL) fluid, and oxidative stress was evaluated biochemically by measuring lipid peroxidation, reduced glutathione and several antioxidant enzymes. Pulmonary inflammation assessment showed an increase in neutrophil and lymphocyte numbers. Likewise, airway resistance was significantly increased in the WPS group compared with controls. Tumor necrosis factor α and interleukin 6 concentrations were significantly increased in BAL fluid. Lipid peroxidation in lung tissue was significantly increased whereas the level and activity of antioxidants including reduced glutathione, glutathione S transferase, and superoxide dismutase were all significantly decreased following WPS exposure, indicating the occurrence of oxidative stress. Moreover, carboxyhemoglobin levels were significantly increased in the WPS group. We conclude that 1-mo nose-only exposure to WPS significantly increased airway resistance, inflammation, and oxidative stress. Our results provide a mechanistic explanation for the limited clinical studies that reported the detrimental respiratory effects of WPS.

  19. A zebrafish model of glucocorticoid resistance shows serotonergic modulation of the stress response

    Directory of Open Access Journals (Sweden)

    Brian eGriffiths

    2012-10-01

    Full Text Available One function of glucocorticoids is to restore homeostasis after an acute stress response by providing negative feedback to stress circuits in the brain. Loss of this negative feedback leads to elevated physiological stress and may contribute to depression, anxiety and post-traumatic stress disorder. We investigated the early, developmental effects of glucocorticoid signaling deficits on stress physiology and related behaviors using a mutant zebrafish, grs357, with non-functional glucocorticoid receptors. These mutants are morphologically inconspicuous and adult-viable. A previous study of adult grs357 mutants showed loss of glucocorticoid-mediated negative feedback and elevated physiological and behavioral stress markers. Already at five days post-fertilization, mutant larvae had elevated whole body cortisol, increased expression of pro-opiomelanocortin (POMC, the precursor of adrenocorticotropic hormone (ACTH, and failed to show normal suppression of stress markers after dexamethasone treatment. Mutant larvae had larger auditory-evoked startle responses compared to wildtype sibling controls (grwt, despite having lower spontaneous activity levels. Fluoxetine (Prozac treatment in mutants decreased startle responding and increased spontaneous activity, making them behaviorally similar to wildtype. This result mirrors known effects of selective serotonin reuptake inhibitors (SSRIs in modifying glucocorticoid signaling and alleviating stress disorders in human patients. Our results suggest that larval grs357 zebrafish can be used to study behavioral, physiological and molecular aspects of stress disorders. Most importantly, interactions between glucocorticoid and serotonin signaling appear to be highly conserved among vertebrates, suggesting deep homologies at the neural circuit level and opening up new avenues for research into psychiatric conditions.

  20. Slow crack growth resistance and bridging stress determination in alumina-rich magnesium aluminate spinel/tungsten composites

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Suarez, T.; Lopez-Esteban, S.; Pecharroman, C. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), C/ Sor Juana Ines de la Cruz, 3, 28049 Cantoblanco, Madrid (Spain); Moya, J.S. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), C/ Sor Juana Ines de la Cruz, 3, 28049 Cantoblanco, Madrid (Spain)], E-mail: jsmoya@icmm.csic.es; El Attaoui, H.; Benaqqa, C.; Chevalier, J. [Universite de Lyon, INSA-Lyon, MATEIS, UMR CNRS 5510, 20 avenue Albert Einstein, Villeurbanne F-69621 (France)

    2009-04-15

    The slow crack growth (SCG) resistance (V-K{sub I} diagrams) of magnesium aluminate spinel and its tungsten composites with different metallic content (7, 10, 14 and 22 vol.%) is reported. It is found that tungsten plays a crucial role in the composite by increasing crack resistance: the higher the W content, the higher the stress intensity factor needed for crack extension at a given rate. The reinforcement is due to the bridging mechanism performed by metal particles, as it strongly affects the compliance of cracked specimens. Its magnitude is estimated by a compliance function {phi}(a) from a double torsion test. From the compliance function, R-curve behaviour is predicted for the composite with highest tungsten content. It explains the effect of metal particles on SCG curves. The W-MgAl{sub 2}O{sub 4} interface is believed to influence the reinforcement mechanism.

  1. Sulfide Stress Corrosion Cracking Resistance of Modified ASTM A694 F60 Low Alloy Steel for Subsea Applications

    OpenAIRE

    Stridsklev, Camilla A

    2013-01-01

    The resistance to sulfide stress corrosion cracking (SSC) of modified ASTM A694 F60 low alloy steel, produced by two different manufacturers, was studied by four-point bend-testing. The two materials are named material A and material B in this report. Both materials were tested in two different environments with different severity, one ?sweet-transition region? test and one ?sour service? test. The test conditions were controlled by the H2S partial pressure (pH2S) and pH. These parameters wer...

  2. Açaí (Euterpe oleracea Mart.) Modulates Oxidative Stress Resistance in Caenorhabditis elegans by Direct and Indirect Mechanisms

    OpenAIRE

    Bonomo, Larissa de Freitas; Silva, David Nunes; Boasquivis, Patrícia Ferreira; Paiva, Franciny Aparecida; Guerra, Joyce Ferreira da Costa; Martins, Talita Alves Faria; de Jesus Torres, Álvaro Gustavo; de Paula, Igor Thadeu Borges Raposo; Caneschi, Washington Luiz; Jacolot, Philippe; Grossin, Nicolas; Tessier, Frederic J.; Boulanger, Eric; Silva, Marcelo Eustáquio; Pedrosa, Maria Lúcia

    2014-01-01

    Açaí (Euterpe oleracea Mart.) has recently emerged as a promising source of natural antioxidants. Despite its claimed pharmacological and nutraceutical value, studies regarding the effects of açaí in vivo are limited. In this study, we use the Caenorhabditis elegans model to evaluate the in vivo antioxidant properties of açaí on an organismal level and to examine its mechanism of action. Supplementation with açaí aqueous extract (AAE) increased both oxidative and osmotic stress resistance ind...

  3. Cinnamon intake alleviates the combined effects of dietary-induced insulin resistance and acute stress on brain mitochondria.

    Science.gov (United States)

    Couturier, Karine; Hininger, Isabelle; Poulet, Laurent; Anderson, Richard A; Roussel, Anne-Marie; Canini, Frédéric; Batandier, Cécile

    2016-02-01

    Insulin resistance (IR), which is a leading cause of the metabolic syndrome, results in early brain function alterations which may alter brain mitochondrial functioning. Previously, we demonstrated that rats fed a control diet and submitted to an acute restraint stress exhibited a delayed mitochondrial permeability transition pore (mPTP) opening. In this study, we evaluated the combined effects of dietary and emotional stressors as found in western way of life. We studied, in rats submitted or not to an acute stress, the effects of diet-induced IR on brain mitochondria, using a high fat/high fructose diet (HF(2)), as an IR inducer, with addition or not of cinnamon as an insulin sensitizer. We measured Ca(2+) retention capacity, respiration, ROS production, enzymatic activities and cell signaling activation. Under stress, HF(2) diet dramatically decreased the amount of Ca(2+) required to open the mPTP (13%) suggesting an adverse effect on mitochondrial survival. Cinnamon added to the diet corrected this negative effect and resulted in a partial recovery (30%). The effects related to cinnamon addition to the diet could be due to its antioxidant properties or to the observed modulation of PI3K-AKT-GSK3β and MAPK-P38 pathways or to a combination of both. These data suggest a protective effect of cinnamon on brain mitochondria against the negative impact of an HF(2) diet. Cinnamon could be beneficial to counteract deleterious dietary effects in stressed conditions. PMID:26878796

  4. A two-component histidine kinase Shk1 controls stress response, sclerotial formation and fungicide resistance in Sclerotinia sclerotiorum.

    Science.gov (United States)

    Duan, Yabing; Ge, Changyan; Liu, Shengming; Wang, Jianxin; Zhou, Mingguo

    2013-09-01

    Fungal histidine kinases (HKs) are involved in osmotic and oxidative stress responses, hyphal development, fungicide sensitivity and virulence. Members of HK class III are known to signal through the high-osmolarity glycerol mitogen-activated protein kinase (HOG MAPK). In this study, we characterized the Shk1 gene (SS1G_12694.3), which encodes a putative class III HK, from the plant pathogen Sclerotinia sclerotiorum. Disruption of Shk1 resulted in resistance to phenylpyrrole and dicarboximide fungicides and increased sensitivity to hyperosmotic stress and H2 O2 -induced oxidative stress. The Shk1 mutant showed a significant reduction in vegetative hyphal growth and was unable to produce sclerotia. Quantitative real-time polymerase chain reaction (qRT-PCR and glycerol determination assays showed that the expression of SsHOG1 (the last kinase of the Hog pathway) and glycerol accumulation were regulated by the Shk1 gene, but PAK (p21-activated kinase) was not. In addition, the Shk1 mutant showed no change in virulence. All the defects were restored by genetic complementation of the Shk1 deletion mutant with the wild-type Shk1 gene. These findings indicate that Shk1 is involved in vegetative differentiation, sclerotial formation, glycerol accumulation and adaption to hyperosmotic and oxidative stresses, and to fungicides, in S. sclerotiorum. Taken together, our results demonstrate, for the first time, the role of two-component HKs in Sclerotinia.

  5. A two-component histidine kinase Shk1 controls stress response, sclerotial formation and fungicide resistance in Sclerotinia sclerotiorum.

    Science.gov (United States)

    Duan, Yabing; Ge, Changyan; Liu, Shengming; Wang, Jianxin; Zhou, Mingguo

    2013-09-01

    Fungal histidine kinases (HKs) are involved in osmotic and oxidative stress responses, hyphal development, fungicide sensitivity and virulence. Members of HK class III are known to signal through the high-osmolarity glycerol mitogen-activated protein kinase (HOG MAPK). In this study, we characterized the Shk1 gene (SS1G_12694.3), which encodes a putative class III HK, from the plant pathogen Sclerotinia sclerotiorum. Disruption of Shk1 resulted in resistance to phenylpyrrole and dicarboximide fungicides and increased sensitivity to hyperosmotic stress and H2 O2 -induced oxidative stress. The Shk1 mutant showed a significant reduction in vegetative hyphal growth and was unable to produce sclerotia. Quantitative real-time polymerase chain reaction (qRT-PCR and glycerol determination assays showed that the expression of SsHOG1 (the last kinase of the Hog pathway) and glycerol accumulation were regulated by the Shk1 gene, but PAK (p21-activated kinase) was not. In addition, the Shk1 mutant showed no change in virulence. All the defects were restored by genetic complementation of the Shk1 deletion mutant with the wild-type Shk1 gene. These findings indicate that Shk1 is involved in vegetative differentiation, sclerotial formation, glycerol accumulation and adaption to hyperosmotic and oxidative stresses, and to fungicides, in S. sclerotiorum. Taken together, our results demonstrate, for the first time, the role of two-component HKs in Sclerotinia. PMID:23724858

  6. Angiogenesis inhibitor vasohibin-1 enhances stress resistance of endothelial cells via induction of SOD2 and SIRT1.

    Directory of Open Access Journals (Sweden)

    Hiroki Miyashita

    Full Text Available Vasohibin-1 (VASH1 is isolated as an endothelial cell (EC-produced angiogenesis inhibitor. We questioned whether VASH1 plays any role besides angiogenesis inhibition, knocked-down or overexpressed VASH1 in ECs, and examined the changes of EC property. Knock-down of VASH1 induced premature senescence of ECs, and those ECs were easily killed by cellular stresses. In contrast, overexpression of VASH1 made ECs resistant to premature senescence and cell death caused by cellular stresses. The synthesis of VASH1 was regulated by HuR-mediated post-transcriptional regulation. We sought to define the underlying mechanism. VASH1 increased the expression of (superoxide dismutase 2 SOD2, an enzyme known to quench reactive oxygen species (ROS. Simultaneously, VASH1 augmented the synthesis of sirtuin 1 (SIRT1, an anti-aging protein, which improved stress tolerance. Paraquat generates ROS and causes organ damage when administered in vivo. More VASH1 (+/- mice died due to acute lung injury caused by paraquat. Intratracheal administration of an adenovirus vector encoding human VASH1 augmented SOD2 and SIRT1 expression in the lungs and prevented acute lung injury caused by paraquat. Thus, VASH1 is a critical factor that improves the stress tolerance of ECs via the induction of SOD2 and SIRT1.

  7. Beneficial effects of wheat gluten hydrolysate to extend lifespan and induce stress resistance in nematode Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Weiming Zhang

    Full Text Available Previous studies have showed that wheat gluten hydrolysate (WGH has the anti-oxidative property. In the present study, we examined the possible safety property of WGH and the beneficial effects of WGH to extend lifespan and induce stress resistance using nematode Caenorhabditis elegans as the in vivo assay system. We found that WGH at concentrations of 0.1-1 mg/mL did not cause lethality, influence development, alter locomotion behavior and brood size, and induce significant intestinal autofluorescence and reactive oxygen species (ROS production in young adults. Treatment with 0.1-1 mg/mL of WGH significantly extended lifespans of nematodes under the normal conditions. Moreover, WGH treatment significantly inhibited the induction of intestinal autofluorescence and suppressed the decrease in locomotion behavior during the aging process of nematodes. Furthermore, pre-treatment with 1 mg/mL of WGH significantly suppressed the adverse effects caused by heat-stress or oxidative stress on nematodes as indicated by the alterations of both lifespan and intestinal ROS production. Therefore, WGH treatment is relatively safe and has beneficial effects on nematodes under both the normal conditions and the stress conditions.

  8. Evaluation of stress and saturation effects on seismic velocity and electrical resistivity - laboratory testing of rock samples

    Science.gov (United States)

    Vilhelm, Jan; Jirků, Jaroslav; Slavík, Lubomír; Bárta, Jaroslav

    2016-04-01

    Repository, located in a deep geological formation, is today considered the most suitable solution for disposal of spent nuclear fuel and high-level waste. The geological formations, in combination with an engineered barrier system, should ensure isolation of the waste from the environment for thousands of years. For long-term monitoring of such underground excavations special monitoring systems are developed. In our research we developed and tested monitoring system based on repeated ultrasonic time of flight measurement and electrical resistivity tomography (ERT). As a test site Bedřichov gallery in the northern Bohemia was selected. This underground gallery in granitic rock was excavated using Tunnel Boring Machine (TBM). The seismic high-frequency measurements are performed by pulse-transmission technique directly on the rock wall using one seismic source and three receivers in the distances of 1, 2 and 3 m. The ERT measurement is performed also on the rock wall using 48 electrodes. The spacing between electrodes is 20 centimeters. An analysis of relation of seismic velocity and electrical resistivity on water saturation and stress state of the granitic rock is necessary for the interpretation of both seismic monitoring and ERT. Laboratory seismic and resistivity measurements were performed. One series of experiments was based on uniaxial loading of dry and saturated granitic samples. The relation between stress state and ultrasonic wave velocities was tested separately for dry and saturated rock samples. Other experiments were focused on the relation between electrical resistivity of the rock sample and its saturation level. Rock samples with different porosities were tested. Acknowledgments: This work was partially supported by the Technology Agency of the Czech Republic, project No. TA 0302408

  9. Rec-8 dimorphism affects longevity, stress resistance and X-chromosome nondisjunction in C. elegans, and replicative lifespan in yeast

    Directory of Open Access Journals (Sweden)

    Srinivas eAyyadevara

    2014-08-01

    Full Text Available A quantitative trait locus (QTL in the nematode C. elegans, lsq4, was recently implicated by mapping longevity genes. QTLs for lifespan and 3 stress-resistance traits coincided within a span of <300 kbp, later narrowed to <200 kbp. A single gene in this interval is now shown to modulate all lsq4-associated traits. Full-genome analysis of transcript levels indicates that lsq4 contains a dimorphic gene governing expression of sperm-specific genes, suggesting effects on spermatogenesis. Quantitation of allele-specific transcripts encoded within the lsq4 interval revealed significant, 2- to 15-fold expression differences for 10 of 33 genes. Fourteen genes, implicated by both position and expression, were tested for RNA-interference effects on QTL-linked traits. In a strain carrying the shorter-lived allele, knockdown of rec-8 (encoding a meiotic cohesin reduced its transcripts 4-fold, to a level similar to the longer-lived strain, and extended lifespan 25–26% whether begun before fertilization or at maturity. The short-lived lsq4 allele also conferred sensitivity to oxidative and thermal stresses, and lower male frequency, traits reversed uniquely by rec-8 knockdown. A strain bearing the longer-lived lsq4 allele, differing from the short-lived strain at <0.3% of its genome, derived no lifespan or stress-survival benefit from rec-8 knockdown. We consider two possible explanations: high rec-8 expression may include increased leaky expression in mitotic cells, leading to deleterious destabilization of somatic genomes; or REC-8 may act entirely in germ-line meiotic cells to reduce aberrations such as nondisjunction, thereby blunting a stress-resistance response mediated by innate immunity. Replicative lifespan was extended 20% in haploid S. cerevisiae (BY4741 by deletion of REC8, orthologous to nematode rec-8, implying that REC8 disruption of mitotic-cell survival is widespread, reflecting antagonistic pleiotropy and/or balancing selection.

  10. In Candida parapsilosis the ATC1 gene encodes for an acid trehalase involved in trehalose hydrolysis, stress resistance and virulence.

    Directory of Open Access Journals (Sweden)

    Ruth Sánchez-Fresneda

    Full Text Available An ORF named CPAR2-208980 on contig 005809 was identified by screening a Candida parapsilosis genome data base. Its 67% identity with the acid trehalase sequence from C. albicans (ATC1 led us to designate it CpATC1. Homozygous mutants that lack acid trehalase activity were constructed by gene disruption at the two CpATC1 chromosomal alleles. Phenotypic characterization showed that atc1Δ null cells were unable to grow on exogenous trehalose as carbon source, and also displayed higher resistance to environmental challenges, such as saline exposure (1.2 M NaCl, heat shock (42°C and both mild and severe oxidative stress (5 and 50 mM H2O2. Significant amounts of intracellular trehalose were specifically stored in response to the thermal upshift in both wild type and mutant strains. Analysis of their antioxidant activities revealed that catalase was only triggered in response to heat shock in atc1Δ cells, whereas glutathione reductase was activated upon mild oxidative stress in wild type and reintegrant strains, and in response to the whole set of stress treatments in the homozygous mutant. Furthermore, yeast cells with double CpATC1 deletion were significantly attenuated in non-mammalian infection models, suggesting that CpATC1 is required for the pathobiology of the fungus. Our results demonstrate the involvement of CpAtc1 protein in the physiological hydrolysis of external trehalose in C. parapsilosis, where it also plays a major role in stress resistance and virulence.

  11. Adrenaline modulates the global transcriptional profile of Salmonella revealing a role in the antimicrobial peptide and oxidative stress resistance responses

    Directory of Open Access Journals (Sweden)

    Williams P

    2008-10-01

    Full Text Available Abstract Background The successful interaction of bacterial pathogens with host tissues requires the sensing of specific chemical and physical cues. The human gut contains a huge number of neurons involved in the secretion and sensing of a class of neuroendocrine hormones called catecholamines. Recently, in Escherichia coli O157:H7, the catecholamines adrenaline and noradrenaline were shown to act synergistically with a bacterial quorum sensing molecule, autoinducer 3 (AI-3, to affect bacterial virulence and motility. We wished to investigate the impact of adrenaline on the biology of Salmonella spp. Results We have determined the effect of adrenaline on the transcriptome of the gut pathogen Salmonella enterica serovar Typhimurium. Addition of adrenaline led to an induction of key metal transport systems within 30 minutes of treatment. The oxidative stress responses employing manganese internalisation were also elicited. Cells lacking the key oxidative stress regulator OxyR showed reduced survival in the presence of adrenaline and complete restoration of growth upon addition of manganese. A significant reduction in the expression of the pmrHFIJKLM antimicrobial peptide resistance operon reduced the ability of Salmonella to survive polymyxin B following addition of adrenaline. Notably, both phenotypes were reversed by the addition of the β-adrenergic blocker propranolol. Our data suggest that the BasSR two component signal transduction system is the likely adrenaline sensor mediating the antimicrobial peptide response. Conclusion Salmonella are able to sense adrenaline and downregulate the antimicrobial peptide resistance pmr locus through the BasSR two component signalling system. Through iron transport, adrenaline may affect the oxidative stress balance of the cell requiring OxyR for normal growth. Both adrenaline effects can be inhibited by the addition of the β-adrenergic blocker propranolol. Adrenaline sensing may provide an environmental

  12. Reviews Related to the Techniques of Enhancing Microbial Stress Resistance%提高微生物抗逆性技术的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘玉萍; 唐鸿志; 许平

    2014-01-01

    Various stress resistant genes or mechanisms presented in microorganisms, and the discovery of these mechanisms laid a sound foundation for the directional enhancement of microbial stress tolerance. The main techniques of enhancing stress resistance of microorganisms contain over expression of stress-resistant genes, long-term adaptive evolution, genome shuffling, and heterologous expression of stress-resistant genes. These biological techniques can efficiently improve the stress resistance of industrial and environmental microorganisms, which surely benefited the bacteria based on industrial production and degradation of environmental pollutants.%微生物体内存在多种抗逆基因或机制,这些机制的发现为定向提高微生物的抗逆性奠定了基础。提高微生物抗逆性的技术主要有过表达抗逆基因,长期适应性进化, genome shuffling(基因组改组)和异源表达抗逆基因等。利用这几种技术增强微生物的抗逆性,在以微生物为主的工业生产和环境污染物降解方面有着广阔的应用前景。

  13. Resistance of the Extreme Halophile Halobacterium sp. NRC-1 to Multiple Stresses

    International Nuclear Information System (INIS)

    The model Archaeon Halobacterium sp. NRC-1 is an extreme halophile known for its resistance to multiple stressors, including electron-beam and ultraviolet radiation. It is a well-developed system with a completely sequenced genome and extensive post-genomic tools for the study of a variety of biological processes. To further understand the mechanisms of Halobacterium's, radiation resistance, we previously reported the selection for multiple independent highly resistant mutants using repeated exposure to high doses of 18-20 MeV electrons using a medical S-band Linac. Molecular analysis of the transcriptional profile of several of these mutants revealed a single common change: upregulation of the rfa3 operon. These genes encode proteins homologous to the subunits of eukaryotic Replication Protein A (RPA), a DNA binding protein with major roles in DNA replication, recombination, and repair. This operon has also been implicated in a somewhat lesser role in resistance of wild type Halobacterium to ultraviolet radiation, suggesting common mechanisms for resistance. To further understand the mechanism of radiation resistance in the mutant strains, we measured the survival after exposure to both electron-beam and ultraviolet radiation, UV-A, B, and C All mutant strains showed increased resistance to electrons when compared with the parent. However, the mutant strains do not display increased UV resistance, and in one case is more sensitive than the parent strain. Thus, the protective role of increased RPA expression within a cell may be specific to the DNA damage caused by the different physical effects induced by high energy electron-beam radiation.

  14. Effect of trans-cinnamaldehyde on reducing resistance to environmental stresses in Cronobacter sakazakii.

    Science.gov (United States)

    Amalaradjou, Mary Anne Roshni; Venkitanarayanan, Kumar

    2011-03-01

    Cronobacter sakazakii is an emerging foodborne pathogen transmitted exclusively through contaminated infant formula (IFM), and associated with life-threatening infections in infants. C. sakazakii has the ability to tolerate a variety of environmental stress conditions, including heat stress, acidity, high osmotic pressure, and desiccation. In this study, we investigated the efficacy of a subinhibitory concentration (750 μM) of trans-cinnamaldehyde (TC), an ingredient in cinnamon, for reducing C. sakazakii's tolerance to these environmental stresses. Three strains of TC-treated C. sakazakii were separately subjected to high temperature (50°C, 55°C, and 60°C), acidic pH (3.3), high osmotic pressure (a(w) 0.81), and desiccation. TC (750 μM) substantially (p < 0.05) compromised stress tolerance of C. sakazakii compared to C. sakazakii cells not exposed to TC. Real-time quantitative polymerase chain reaction results revealed that TC significantly (p < 0.05) downregulated C. sakazakii genes critical for stress tolerance and survival, including rpoS, chaperonins, phoP/Q, outer membrane porins, and osmolyte transporter genes. The efficacy of TC in reducing C. sakazakii stress tolerance underscores its potential use for controlling the pathogen by increasing its susceptibility to commonly applied hurdles in food processing. PMID:21114424

  15. Accelerated fat cell aging links oxidative stress and insulin resistance in adipocytes

    Indian Academy of Sciences (India)

    Finny Monickaraj; Sankaramoorthy Aravind; Pichamoorthy Nandhini; Paramasivam Prabu; Chandrakumar Sathishkumar; Viswanathan Mohan; Muthuswamy Balasubramanyam

    2013-03-01

    Telomere shortening is emerging as a biological indicator of accelerated aging and aging-related diseases including type 2 diabetes. While telomere length measurements were largely done in white blood cells, there is lack of studies on telomere length in relation to oxidative stress in target tissues affected in diabetes. Therefore, the aim of this study is to induct oxidative stress in adipocytes and to test whether these adipocytes exhibit shortened telomeres, senescence and functional impairment. 3T3-L1 adipocytes were subjected to oxidative stress and senescence induction by a variety of means for 2 weeks (exogenous application of H2O2, glucose oxidase, asymmetric dimethylarginine (ADMA) and glucose oscillations). Cells were probed for reactive oxygen species generation (ROS), DNA damage, mRNA and protein expression of senescent and pro-inflammatory markers, telomere length and glucose uptake. Compared to untreated cells, both ROS generation and DNA damage were significantly higher in cells subjected to oxidative stress and senescence. Adipocytes subjected to oxidative stress also showed shortened telomeres and increased mRNA and protein expression of p53, p21, TNF and IL-6. Senescent cells were also characterized by decreased levels of adiponectin and impaired glucose uptake. Briefly, adipocytes under oxidative stress exhibited increased ROS generation, DNA damage, shortened telomeres and switched to senescent/pro-inflammatory phenotype with impaired glucose uptake.

  16. In-season heat stress compromises postharvest quality and low-temperature sweetening resistance in potato (Solanum tuberosum L.).

    Science.gov (United States)

    Zommick, Daniel H; Knowles, Lisa O; Pavek, Mark J; Knowles, N Richard

    2014-06-01

    The effects of soil temperature during tuber development on physiological processes affecting retention of postharvest quality in low-temperature sweetening (LTS) resistant and susceptible potato cultivars were investigated. 'Premier Russet' (LTS resistant), AO02183-2 (LTS resistant) and 'Ranger Russet' (LTS susceptible) tubers were grown at 16 (ambient), 23 and 29 °C during bulking (111-164 DAP) and maturation (151-180 DAP). Bulking at 29 °C virtually eliminated yield despite vigorous vine growth. Tuber specific gravity decreased as soil temperature increased during bulking, but was not affected by temperature during maturation. Bulking at 23 °C and maturation at 29 °C induced higher reducing sugar levels in the proximal (basal) ends of tubers, resulting in non-uniform fry color at harvest, and abolished the LTS-resistant phenotype of 'Premier Russet' tubers. AO02183-2 tubers were more tolerant of heat for retention of LTS resistance. Higher bulking and maturation temperatures also accelerated LTS and loss of process quality of 'Ranger Russet' tubers, consistent with increased invertase and lower invertase inhibitor activities. During LTS, tuber respiration fell rapidly to a minimum as temperature decreased from 9 to 4 °C, followed by an increase to a maximum as tubers acclimated to 4 °C; respiration then declined over the remaining storage period. The magnitude of this cold-induced acclimation response correlated directly with the extent of buildup in sugars over the 24-day LTS period and thus reflected the effects of in-season heat stress on propensity of tubers to sweeten and lose process quality at 4 °C. While morphologically indistinguishable from control tubers, tubers grown at elevated temperature had different basal metabolic (respiration) rates at harvest and during cold acclimation, reduced dormancy during storage, greater increases in sucrose and reducing sugars and associated loss of process quality during LTS, and reduced ability to improve

  17. Performance of stress resistant variants of Listeria monocytogenes in mixed species biofilms with Lactobacillus plantarum.

    Science.gov (United States)

    Metselaar, Karin I; Saá Ibusquiza, Paula; Ortiz Camargo, Angela R; Krieg, Myriam; Zwietering, Marcel H; den Besten, Heidy M W; Abee, Tjakko

    2015-11-20

    Population diversity and the ability to adapt to changing environments allow Listeria monocytogenes to grow and survive under a wide range of environmental conditions. In this study, we aimed to evaluate the performance of a set of acid resistant L. monocytogenes variants in mixed-species biofilms with Lactobacillus plantarum as well as their benzalkonium chloride (BAC) resistance in these biofilms. L. monocytogenes LO28 wild type and acid resistant variants were capable of forming mixed biofilms with L. plantarum at 20°C and 30°C in BHI supplemented with manganese and glucose. Homolactic fermentation of glucose by L. plantarum created an acidic environment with pH values below the growth boundary of L. monocytogenes. Some of the variants were able to withstand the low pH in the mixed biofilms for a longer time than the WT and there were clear differences in survival between the variants which could not be correlated to (lactic) acid resistance alone. Adaptation to mild pH of liquid cultures during growth to stationary phase increased the acid resistance of some variants to a greater extent than of others, indicating differences in adaptive behaviour between the variants. Two variants that showed a high level of acid adaptation when grown in liquid cultures, showed also better performance in mixed species biofilms. There were no clear differences in BAC resistance between the wild type and variants in mixed biofilms. It can be concluded that acid resistant variants of L. monocytogenes show diversity in their adaptation to acidic conditions and their capacity to survive in mixed cultures and biofilms with L. plantarum.

  18. Standardized Extract of Bacopa monniera Attenuates Okadaic Acid Induced Memory Dysfunction in Rats: Effect on Nrf2 Pathway

    Directory of Open Access Journals (Sweden)

    Subhash Dwivedi

    2013-01-01

    Full Text Available The aim of the present study is to investigate the effect of standardized extract of Bacopa monnieri (memory enhancer and Melatonin (an antioxidant on nuclear factor erythroid 2 related factor 2 (Nrf2 pathway in Okadaic acid induced memory impaired rats. OKA (200 ng was administered intracerebroventricularly (ICV to induce memory impairment in rats. Bacopa monnieri (BM-40 and 80 mg/kg and Melatonin (20 mg/kg were administered 1 hr before OKA injection and continued daily up to day 13. Memory functions were assessed by Morris water maze test on days 13–15. Rats were sacrificed for biochemical estimations of oxidative stress, neuroinflammation, apoptosis, and molecular studies of Nrf2, HO1, and GCLC expressions in cerebral cortex and hippocampus brain regions. OKA caused a significant memory deficit with oxidative stress, neuroinflammation, and neuronal loss which was concomitant with attenuated expression of Nrf2, HO1, and GCLC. Treatment with BM and Melatonin significantly improved memory dysfunction in OKA rats as shown by decreased latency time and path length. The treatments also restored Nrf2, HO1, and GCLC expressions and decreased oxidative stress, neuroinflammation, and neuronal loss. Thus strengthening the endogenous defense through Nrf2 modulation plays a key role in the protective effect of BM and Melatonin in OKA induced memory impairment in rats.

  19. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  20. A Peroxiredoxin Promotes H2O2 Signaling and Oxidative Stress Resistance by Oxidizing a Thioredoxin Family Protein

    Directory of Open Access Journals (Sweden)

    Jonathon D. Brown

    2013-12-01

    Full Text Available H2O2 can cause oxidative damage associated with age-related diseases such as diabetes and cancer but is also used to initiate diverse responses, including increased antioxidant gene expression. Despite significant interest, H2O2-signaling mechanisms remain poorly understood. Here, we present a mechanism for the propagation of an H2O2 signal that is vital for the adaptation of the model yeast, Schizosaccharomyces pombe, to oxidative stress. Peroxiredoxins are abundant peroxidases with conserved antiaging and anticancer activities. Remarkably, we find that the only essential function for the thioredoxin peroxidase activity of the Prx Tpx1(hPrx1/2 in resistance to H2O2 is to inhibit a conserved thioredoxin family protein Txl1(hTxnl1/TRP32. Thioredoxins regulate many enzymes and signaling proteins. Thus, our discovery that a Prx amplifies an H2O2 signal by driving the oxidation of a thioredoxin-like protein has important implications, both for Prx function in oxidative stress resistance and for responses to H2O2.

  1. Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae▿

    OpenAIRE

    Abbott, D.A.; Suir, E.; Duong, G.H.; De Hulster, E.; Pronk, J. T.; van Maris, A J A

    2009-01-01

    Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2{Delta} reference strain, used to avoid aerobic consumption of lactic acid, had a specific growth rate of 0.25 h–1 ...

  2. Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Abbott, D.A.; Suir, E.; Duong, G.H.; De Hulster, E.; Pronk, J.T.; Van Maris, A.J.A.

    2009-01-01

    Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an i

  3. Cloning and functional identification of stress-resistant BeDREB genes from Bermuda grass

    Institute of Scientific and Technical Information of China (English)

    XIE Yongli; WANG Zizhang; LIU Qiang; ZHANG Shuping

    2006-01-01

    Dehydration-responsive element-binding (DREB)proteins,specifically binding to the dehydration-responsive element (DRE),have been identified as a group of important transcription activators of plants which regulate the expression of genes in response to drought,high-salt and low- temperature stresses.Two DREB-like genes from Bermuda grass that are induced by low-temperature or high-salt stresses were cloned using RT-PCR and RACE methods,and were named BeDREB1 and BeDREB2,respectively (GenBank accession No:AY462117 and AY462118).They contained an ORF of 753 bp encoding 251 amino acids,showing the typical characteristics of the DREB gene family.Interestingly,these two genes isolated from Bermuda grass induced either by low-temperature stress or high-salt stress shared 97.8% homology.Furthermore,it was demonstrated that both BeDREB1 and BeDREB2 could bind to the wild-type DRE element to activate the transcription of the reporter gene HIS3,driven by a promoter carrying DRE cis-element in yeast strain 4721,in the presence of 3-AT.RT-PCR showed that BeDREB1 and BeDREB2 genes could be greatly induced by low-temperature and high-salt stresses,respectively.Their expressions were changed following the inducible time.In conclusion,all results indicate that BeDREB1 and BeDREB2 genes isolated from treated Bermuda grass are new members'of the DREB transcription activator family,which may play very important roles in signal transduction related to stresses.

  4. Nicotiana tabacum Tsip1-Interacting Ferredoxin 1 Affects Biotic and Abiotic Stress Resistance

    OpenAIRE

    Huh, Sung Un; Lee, In-Ju; Ham, Byung-Kook; Paek, Kyung-Hee

    2012-01-01

    Tsip1, a Zn finger protein that was isolated as a direct interactor with tobacco stress-induced 1 (Tsi1), plays an important role in both biotic and abiotic stress signaling. To further understand Tsip1 function, we searched for more Tsip1-interacting proteins by yeast two-hybrid screening using a tobacco cDNA library. Screening identified a new Tsip1-interacting protein, Nicotiana tabacum Tsip1-interacting ferredoxin 1 (NtTfd1), and binding specificity was confirmed both in vitro and in vivo...

  5. Therapeutic effects of hydrogen saturated saline on rat diabetic model and insulin resistant model via reduction of oxidative stress

    Institute of Scientific and Technical Information of China (English)

    WANG Qi-jin; ZHA Xiao-juan; KANG Zhi-min; XU Mao-jin; HUANG Qin; ZOU Da-jin

    2012-01-01

    Background Molecular hydrogen,as a novel antioxidant,has been proven effective in treating many diseases.This study aimed to evaluate the therapeutic effects of hydrogen saturated saline in treatment of a rat model of diabetes mellitus and a rat model of insulin resistant.Methods A rat diabetes mellitus model was established by feeding a high fat/high carbohydrate diet followed by injection of a small dose of streptozotocin,and an insulin resistant model was induced with a high glucose and high fat diet.Hydrogen saturated saline was administered to rats with both models conditions on a daily basis for eight weeks.A pioglitazone-treated group and normal saline-treated group served as positive and negative controls.The general condition,body weight,blood glucose,blood lipids,and serum insulin levels of rats were examined at the 8th week after treatment.The oxidative stress indices,including serum superoxide dismutase (SOD),glutathione (GSH) and malondialdehyde (MDA) were also evaluated after eight weeks of treatment using the commercial kits.Results Hydrogen saturated saline showed great efficiency in improving the insulin sensitivity and lowering blood glucose and lipids.Meanwhile,the therapeutic effects of hydrogen saturated saline were superior to those of pioglitazone.Hydrogen saturated saline markedly attenuated the MDA level and elevated the levels of antioxidants SOD and GSH.Conclusion Hydrogen saturated saline may improve the insulin resistance and alleviate the symptoms of diabetes mellitus by reducing the oxidative stress and enhancing the anti-oxidant system.

  6. First feeding of Eugerres brasilianus (Carapeva larvae with Acartia tonsa (Copepod nauplii increases survival and resistance to acute stress

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo Costa

    2016-01-01

    Full Text Available The rotifer Brachionus sp. is commonly used for larval feeding in marine fish hatcheries. The aim of this study was to evaluate whether the inclusion of Acartia tonsa nauplii in the initial diet of carapeva larvae improves their survival, growth and resistance to stress when compared to the regimen containing only rotifers. Adult copepods were collected in the wild and cultured with the microalgae Chaetoceros muelleri, Isochrysis galbana and Nannochloropsis oculata to obtain nauplii. Carapeva larvae were grown for 15 days using four treatments and three replicates: 1 Brachionus plicatilis rotifers (10 to 15/mL; 2 A. tonsa nauplii (0.25 to 0.5/mL; 3 Brachionus plicatilis rotifers (5 to 7.5/mL + A. tonsa nauplii (0.12 to 0.25/mL, and 4 no supply of live feed. After 15 days, the carapeva larvae were subjected to stress by exposure to air for 10 seconds and then returned to the source tank to evaluate survival after 24 h. Survival and stress resistance were higher in carapeva larvae fed B. plicatilis + A. tonsa nauplii (P<0.05, 20.9 ± 11.2% and 88.9%, respectively. These results confirm the positive effect of the inclusion of copepod nauplii in the diet of fish larvae. However, more research is needed to validate these results.

  7. Expression of a wheat MYB gene in transgenic tobacco enhances resistance to Ralstonia solanacearum, and to drought and salt stresses.

    Science.gov (United States)

    Liu, Hongxia; Zhou, Xianyao; Dong, Na; Liu, Xin; Zhang, Huaiyu; Zhang, Zengyan

    2011-09-01

    MYB transcription factors play diverse roles in plant growth, developmental processes and stress responses. A full-length cDNA sequence of a MYB gene, namely TaPIMP1, was isolated from wheat (Triticum aestivum L.). The TaPIMP1 transcript level was significantly up-regulated by inoculation with a fungal pathogen Bipolaris sorokiniana and by drought treatment. TaPIMP1 encodes the MYB protein TaPIMP1 consisting of 323 amino acids. TaPIMP1 contains two MYB DNA binding domains (R2, R3), two putative nuclear localization sites and two putative transcription activation domains. TaPIMP1 is a new member of the R2R3-MYB transcription factor subfamily. Transient expression in onion epidermal cells of GFP fused with TaPIMP1 proved that subcellular localization of TaPIMP1 occurred in the nucleus. The TaPIMP1 gene was transferred into tobacco (Nicotiana tabacum L.) cultivar W38 by Agrobacterium-mediated transformation. After screening through PCR and RT-PCR analyses, transgenic tobacco lines expressing TaPIMP1 were identified and evaluated for pathogen resistance, and drought and salt tolerance. Compared to untransformed tobacco host plants, TaPIMP1 expressing plants displayed significantly enhanced resistance to Ralstonia solanacearum and exhibited improved tolerances to drought and salt stresses. In these transgenic lines, the activities of phenylalanine ammonia-lyase (PAL) and superoxide dismutase (SOD) were significantly increased relative to wild-type tobacco plants. The results suggested that the wheat R2R3-MYB transcription factor plays an important role in modulating responses to biotic and abiotic stresses.

  8. Effect of Base and Inlay Restorative Material on the Stress Distribution and Fracture Resistance of Weakened Premolars.

    Science.gov (United States)

    Souza, A C O; Xavier, T A; Platt, J A; Borges, A L S

    2015-01-01

    The purpose of this study was to evaluate the influence of direct base and indirect inlay materials on stress distribution and fracture resistance of endodontically treated premolars with weakened cusps. Forty healthy human premolars were selected; five were left intact as controls (group C+), and the others were subjected to endodontic treatment and removal of buccal and lingual cusp dentin. Five teeth were left as negative controls (group C-). The remaining 30 teeth were divided into two groups according to the direct base material (glass ionomer [GIC] or composite resin [CR]). After base placement, each group was subjected to extensive inlay preparation, and then three subgroups were created (n=5): no inlay restoration (GIC and CR), restored with an indirect composite resin inlay (GIC+IR and CR+IR), and restored with a ceramic inlay (GIC+C and CR+C). Each specimen was loaded until fracture in a universal testing machine. For finite element analysis, the results showed that the removal of tooth structure significantly affected fracture resistance. The lowest values were presented by the negative control group, followed by the restored and based groups (not statistically different from each other) and all lower than the positive control group. In finite element analysis, the stress concentration was lower in the restored tooth compared to the tooth without restoration, whereas in the restored teeth, the stress concentration was similar, regardless of the material used for the base or restoration. It can be concluded that the inlay materials combined with a base showed similar behavior and were not able to regain the strength of intact tooth structure.

  9. Pathogen-induced Caenorhabditis elegans developmental plasticity has a hormetic effect on the resistance to biotic and abiotic stresses

    Directory of Open Access Journals (Sweden)

    Leroy Magali

    2012-09-01

    Full Text Available Abstract Background Phenotypic plasticity, i.e. the capacity to change the phenotype in response to changes in the environment without alteration of the genotype, is important for coping with unstable environments. In spite of the ample evidence that microorganisms are a major environmental component playing a significant role in eukaryotic organisms health and disease, there is not much information about the effect of microorganism-induced developmental phenotypic plasticity on adult animals’ stress resistance and longevity. Results We examined the consequences of development of Caenorhabditis elegans larvae fed with different bacterial strains on stress resistance and lifespan of adult nematodes. Bacterial strains used in this study were either pathogenic or innocuous to nematodes. Exposure to the pathogen during development did not affect larval survival. However, the development of nematodes on the pathogenic bacterial strains increased lifespan of adult nematodes exposed to the same or a different pathogen. A longer nematode lifespan, developed on pathogens and exposed to pathogens as adults, did not result from an enhanced capacity to kill bacteria, but is likely due to an increased tolerance to the damage inflicted by the pathogenic bacteria. We observed that adult nematodes developed on a pathogen induce higher level of expression of the hsp-16.2 gene and have higher resistance to heat shock than nematodes developed on an innocuous strain. Therefore, the increased resistance to pathogens could be, at least partially, due to the early induction of the heat shock response in nematodes developed on pathogens. The lifespan increase is controlled by the DBL-1 transforming growth factor beta-like, DAF-2/DAF-16 insulin-like, and p38 MAP kinase pathways. Therefore, the observed modulation of adult nematode lifespans by developmental exposure to a pathogen is likely a genetically controlled response. Conclusions Our study shows that development

  10. Loss of NDG-4 extends lifespan and stress resistance in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Brejning, Jeanette; Nørgaard, Steffen; Schøler, Lone Vedel;

    2014-01-01

    NDG-4 is a predicted transmembrane acyltransferase protein that acts in the distribution of lipophilic factors. Consequently, ndg-4 mutants lay eggs with a pale appearance due to lack of yolk, and they are resistant to sterility caused by dietary supplementation with the long-chain omega-6 polyun...

  11. Understanding genetic control of biotic stress resistance in sorghum for applied breeding

    Science.gov (United States)

    Sorghum (Sorghum bicolor (L.) Moench) improvement deals with development of new crop cultivars which are superior to existing cultivars for traits of interest like high yield, better quality, resistance to pests and diseases, and specific usability traits (Reddy et al 2011; Ashok Kumar et al 2013). ...

  12. Influence of stress path change on the resistance to plastic deformation of cold rolled sheets

    Institute of Scientific and Technical Information of China (English)

    Zonghai Ding; Pavel Huml

    2005-01-01

    Flat workpieces have been tested in order to investigate the influence of stress path change (loading mode) while keeping strain path unchanged. These investigations are pertinent to the testing of cold rolled strips and to subsequent forming. The workpieces which first compressed by plane strain compression in thickness direction were then tested in perpendicular direction in order to measure the influence of strain and stress path. The tension workpieces came from flat die compression test at different deformation histories. Two different materials were investigated: 18/8 Ti stainless steel and AW-1050 aluminium. The results show that the plastic flow by tension in lengthwise direction after pre-strain by compression in thickness direction will begin at an appreciably lower stress than that of the workpieces unloaded after pre-compression. Comparing with two materials, it can be seen that both 18/8Ti stainless steel and AW-1050 aluminium behave similarly. The drop in yield stress is lower for AW-1050 aluminium than that for 18/8 Ti stainless steel. However, reloading in different directions than in the precious step results in significantly higher strain hardening.

  13. Acceptance and Commitment Therapy for Treatment-Resistant Posttraumatic Stress Disorder: A Case Study

    Science.gov (United States)

    Twohig, Michael P.

    2009-01-01

    An adult woman with chronic posttraumatic stress disorder (PTSD) and major depressive disorder who was nonresponsive to 20 sessions of cognitive behavior therapy (CBT) is presented in this case study. Two months after her CBT trial, she was treated with 21 sessions of Acceptance and Commitment Therapy (ACT) for PTSD. Measurements of PTSD severity,…

  14. Effect of heat treatment on the stress corrosion resistance of a microalloyed pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Albarran, J.L. [UNAM, Inst. de Fisica, Cuernavaca (Mexico); Martinez, L. [UNAM, Inst. de Fisica, Cuernavaca (Mexico)]|[U.A.C., Programa de Corrosion del Golfo de Mexico (Mexico); Lopez, H.F. [Wisconsin Univ., Materials Dept., Milwaukee, WI (United States)

    1999-11-01

    In this work, the effect of heat treating on a pipeline steel exposed to a sulfide stress cracking (SSC) environment was investigated using LEFM compact specimens. In the as-received condition, specimens with crack orientations parallel and normal to the rolling direction were exposed to H{sub 2}S saturated synthetic sea water at an applied stress intensity (K{sub 1}) of 30 MPa{center_dot}m{sup 1/2}. In both cases, crack propagation rates were very close to each other (da/dt = 8.77 x 10{sup -9}m/s). as the microstructure was modified by heat treating, the rates of crack growth exhibited appreciable differences under similar applied stress intensities. In the martensitic (as-quenched) condition, crack growth was relatively fast (da/dt = 4.72 x 10{sup -7}m/s) indicating severe hydrogen embrittlement. In the water sprayed, and in the quenched and tempered conditions, the LEFM specimens exhibited crack arrest events. This, in turn, enabled the determination of threshold stress intensity values (K{sub issc}) for the water sprayed, and for the quenched and tempered conditions of 26 and 32 MPa{center_dot}m{sup 1/2}, respectively. In addition, favourable paths for microcrack growth were found to be provided by globular inclusions and grain boundary precipitates. (Author)

  15. Combinatorial Strategies for Improving Multiple-Stress Resistance in Industrially Relevant Escherichia coli Strains

    DEFF Research Database (Denmark)

    Lennen, Rebecca; Herrgard, Markus

    2014-01-01

    High-cell-density fermentation for industrial production of chemicals can impose numerous stresses on cells due to high substrate, product, and by-product concentrations; high osmolarity; reactive oxygen species; and elevated temperatures. There is a need to develop platform strains of industrial...

  16. The deletion mutant EGFRvIII significantly contributes to stress resistance typical for the tumour microenvironment

    International Nuclear Information System (INIS)

    Background and purpose: The epidermal growth factor receptor (EGFR) is overexpressed or mutated in many tumour types. The truncated, constitutively active EGFRvIII variant has not been detected in normal tissues but is found in many malignancies. In the current study, we have investigated the hypothesis that EGFRvIII contributes to a growth and survival advantage under tumour microenvironment-related stress conditions. Materials and methods: U373MG doxycycline-regulated isogenic cells expressing EGFRwt or EGFRvIII were created and validated using Western blot, FACS and qRT-PCR. In vitro proliferation was evaluated with standard growth assays. Cell survival was assayed using clonogenic survival. Animal experiments were performed using NMRI-nu-xenografted mice. Results: Inducible isogenic cell lines were created and showed high induction of EGFRwt and EGFRvIII upon doxycycline addition. Overexpression of EGFRvIII but not of EGFRwt in this model resulted in a growth and survival advantage upon different tumour microenvironment-related stress conditions in vitro. Induction of EGFRvIII increased tumour growth in vivo, which was reversible upon loss of expression. Conclusions: Under conditions where nutrients are limited and stress is apparent, as in the tumour microenvironment, expression of EGFRvIII leads to a growth and survival advantage. These data indicate a potential selection of EGFRvIII-expressing tumour cells under such stress conditions.

  17. Protein changes in rice seedlings during the enhancement of chilling resistance by different stress pretreatment

    Institute of Scientific and Technical Information of China (English)

    ZENGShaoxi; WANGYirou; LIMeiru

    1997-01-01

    The changes of proteins in the rice (Oryza sativa L. ) Tesanai 2 seedling under salt ( NaCl ,4 g/L), heat shock (42℃, 3h), and cold(14℃, 3d) pretreatments were compared toexplore the mechanism of the cross adaptationto different environmental stresses.

  18. Clonal plasticity of aquatic plant species submitted to mechanical stress: escape versus resistance strategy

    NARCIS (Netherlands)

    Puijalon, S.; Bouma, T.J.; Van Groenendael, J.M.; Bornette, G.

    2008-01-01

    Background and Aims: The plastic alterations of clonal architecture are likely to have functional consequences, as they affect the spatial distribution of ramets over patchy environments. However, little is known about the effect of mechanical stresses on the clonal growth. The aim of the present st

  19. Encapsulation-Induced Stress Helps Saccharomyces cerevisiae Resist Convertible Lignocellulose Derived Inhibitors

    Directory of Open Access Journals (Sweden)

    Johan O. Westman

    2012-09-01

    Full Text Available The ability of macroencapsulated Saccharomyces cerevisiae CBS8066 to withstand readily and not readily in situ convertible lignocellulose-derived inhibitors was investigated in anaerobic batch cultivations. It was shown that encapsulation increased the tolerance against readily convertible furan aldehyde inhibitors and to dilute acid spruce hydrolysate, but not to organic acid inhibitors that cannot be metabolized anaerobically. Gene expression analysis showed that the protective effect arising from the encapsulation is evident also on the transcriptome level, as the expression of the stress-related genes YAP1, ATR1 and FLR1 was induced upon encapsulation. The transcript levels were increased due to encapsulation already in the medium without added inhibitors, indicating that the cells sensed low stress level arising from the encapsulation itself. We present a model, where the stress response is induced by nutrient limitation, that this helps the cells to cope with the increased stress added by a toxic medium, and that superficial cells in the capsules degrade convertible inhibitors, alleviating the inhibition for the cells deeper in the capsule.

  20. Endoplasmic reticulum stress is involved in the response of human laryngeal carcinoma cells to Carboplatin but is absent in Carboplatin-resistant cells.

    Directory of Open Access Journals (Sweden)

    Anamaria Brozovic

    Full Text Available The major obstacle of successful tumor treatment with carboplatin (CBP is the development of drug resistance. In the present study, we found that following treatment with CBP the amount of platinum which enters the human laryngeal carcinoma (HEp2-derived CBP-resistant (7T cells is reduced relative to the parental HEp2. As a consequence, the formation of reactive oxidative species (ROS is reduced, the induction of endoplasmic reticulum (ER stress is diminished, the amount of inter- and intrastrand cross-links is lower, and the induction of apoptosis is depressed. In HEp2 cells, ROS scavenger tempol, inhibitor of ER stress salubrinal, as well as gene silencing of ER stress marker CCAAT/enhancer-binding protein (CHOP increases their survival and renders them as resistant to CBP as 7T cell subline but did not influence the survival of 7T cells. Our results suggest that in HEp2 cells CBP-induced ROS is a stimulus for ER stress. To the contrary, despite the ability of CBP to induce formation of ROS and activate ER stress in 7T cells, the cell death mechanism in 7T cells is independent of ROS induction and activation of ER stress. The novel signaling pathway of CBP-driven toxicity that was found in the HEp2 cell line, i.e. increased ROS formation and induction of ER stress, may be predictive for therapeutic response of epithelial cancer cells to CBP-based therapy.

  1. Concentration-Dependent Effects of Rhodiola Rosea on Long-Term Survival and Stress Resistance of Yeast Saccharomyces Cerevisiae: The Involvement of YAP 1 and MSN2/4 Regulatory Proteins

    OpenAIRE

    Bayliak, Maria M.; Burdyliuk, Nadia I.; Izers’ka, Lilia I.; Lushchak, Volodymyr I.

    2013-01-01

    Concentration-dependent effects of aqueous extract from R. rosea root on long-term survival and stress resistance of budding yeast Saccharomyces cerevisiae were studied. At low concentrations, R. rosea aqueous extract extended yeast chronological lifespan, enhanced oxidative stress resistance of stationary-phase cells and resistance to number stressors in exponentially growing cultures. At high concentrations, R. rosea extract sensitized yeast cells to stresses and shortened yeast lifespan. T...

  2. Clp chaperones and proteases are central in stress survival, virulence and antibiotic resistance of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Frees, Dorte; Gerth, Ulf; Ingmer, Hanne

    2014-01-01

    Intracellular proteolysis carried out by energy-dependent proteases is one of the most conserved biological processes. In all cells proteolysis maintains and shapes the cellular proteome by ridding the cell of damaged proteins and by regulating abundance of functional proteins such as regulatory...... proteins. The ATP-dependent ClpP protease is highly conserved among eubacteria and in the chloroplasts and mitochondria of eukaryotic cells. In the serious human pathogen, Staphylococcus aureus inactivation of clpP rendered the bacterium avirulent emphasizing the central role of proteolysis in virulence....... The contribution of the Clp proteins to virulence is likely to occur at multiple levels. First of all, both Clp ATPases and the Clp protease are central players in stress responses required to cope with the adverse conditions met in the host. The ClpP protease has a dual role herein, as it both eliminates stress...

  3. The golden root, Rhodiola rosea, prolongs lifespan but decreases oxidative stress resistance in yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Bayliak, Maria M; Lushchak, Volodymyr I

    2011-11-15

    The effect of aqueous extract from R. rosea root on lifespan and the activity of antioxidant enzymes in budding yeast Saccharomyces cerevisiae have been studied. The supplementation of the growth medium with R. rosea extract decreased survival of exponentially growing S. cerevisiae cells under H(2)O(2)-induced oxidative stress, but increased viability and reproduction success of yeast cells in stationary phase. The extract did not significantly affect catalase activity and decreased SOD activity in chronologically aged yeast population. These results suggest that R. rosea acts as a stressor for S. cerevisiae cells, what sensitizes yeast cells to oxidative stress at exponential phase, but induces adaptation in stationary phase cells demonstrating the positive effect on yeast survival without activation of major antioxidant enzymes.

  4. Stress corrosion cracking susceptibility of the earthquake resistant NOM B457 Mexican steel

    International Nuclear Information System (INIS)

    The Mexican construction code was modified after the Mexico city 1985 earthquake, substituted the medium carbon reinforced steel NOM B6 by the new micro alloyed steel NOM B457 in 42 Kg/mm2 grade. The present study reports the evaluation of the NOM B457 steel behavior in mortar with and without 2% wt. in chlorides and in Ca(OH)2 saturated solutions. The results are compared with the NOM B6 steel behavior in the same conditions. The Stress Corrosion Cracking (SCC) is not present in all the conditions used in this study and there are not susceptibility potential range to SCC when the material is evaluated by electrochemical Tests, Constant Extension Rate Tests (CERT) and Constant Load Test at 80 % of yield stress. A susceptibility potential range to Hydrogen Induced Cracking (HIC) is detected, below -900 mV. vs Standard Calomel Electrode (SCE) by CERT at constant potential

  5. The golden root, Rhodiola rosea, prolongs lifespan but decreases oxidative stress resistance in yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Bayliak, Maria M; Lushchak, Volodymyr I

    2011-11-15

    The effect of aqueous extract from R. rosea root on lifespan and the activity of antioxidant enzymes in budding yeast Saccharomyces cerevisiae have been studied. The supplementation of the growth medium with R. rosea extract decreased survival of exponentially growing S. cerevisiae cells under H(2)O(2)-induced oxidative stress, but increased viability and reproduction success of yeast cells in stationary phase. The extract did not significantly affect catalase activity and decreased SOD activity in chronologically aged yeast population. These results suggest that R. rosea acts as a stressor for S. cerevisiae cells, what sensitizes yeast cells to oxidative stress at exponential phase, but induces adaptation in stationary phase cells demonstrating the positive effect on yeast survival without activation of major antioxidant enzymes. PMID:21802922

  6. Deficiency of multidrug resistance 2 contributes to cell transformation through oxidative stress

    OpenAIRE

    Tebbi, Ali; Levillayer, Florence; Jouvion, Grégory; Fiette, Laurence; Soubigou, Guillaume; Varet, Hugo; Boudjadja, Nesrine; Cairo, Stefano; Hashimoto, Kosuke; Suzuki, Ana Maria; Carninci, Piero; Carissimo, Annamaria; di Bernardo, Diego; Wei, Yu

    2015-01-01

    Multidrug resistance 2 (Mdr2), also called adenosine triphosphate-binding cassette B4 (ABCB4), is the transporter of phosphatidylcholine (PC) at the canalicular membrane of mouse hepatocytes, which plays an essential role for bile formation. Mutations in human homologue MDR3 are associated with several liver diseases. Knockout of Mdr2 results in hepatic inflammation, liver fibrosis and hepatocellular carcinoma (HCC). Whereas the pathogenesis in Mdr2 −/− mice has been largely attributed to the...

  7. Cell wall remodelling enzymes modulate fungal cell wall elasticity and osmotic stress resistance

    OpenAIRE

    Ene, Iuliana; Walker, Louise; Schiavone, Marion; Lee, Keunsook K.; Dague, Etienne; Gow, Neil A.R.; Munro, Carol A

    2015-01-01

    The fungal cell wall confers cell morphology and protection against environmental insults. For fungal pathogens, the cell wall is a key immunological modulator and an ideal therapeutic target. Yeast cell walls possess an inner matrix of interlinked β-glucan and chitin that is thought to provide tensile strength and rigidity. Yeast cells remodel their walls over time in response to environmental change, a process controlled by evolutionarily conserved stress (Hog1) and cell integrity (Mkc1, Ce...

  8. Predicting resistance to stress : incremental validity of trait emotional intelligence over alexithymia and optimism

    OpenAIRE

    Mikolajczak, Moïra; Luminet, Olivier; Menil, Clementine

    2006-01-01

    As trait emotional intelligence [TEI] is claimed to facilitate adaptation, study 1 (N= 80) investigated whether TEI would be associated with adaptative outcomes such as enhanced self-reported mental and physical health. As these assumptions were supported, study 2 (N= 75) tested the hypothesis of a moderating effect of TEI on the relationship between stress and psychological and somatic health. Incremental validity of TEI over alexithymia and optimism was also examined. We chose academic exam...

  9. DEK Is a Poly(ADP-Ribose) Acceptor in Apoptosis and Mediates Resistance to Genotoxic Stress

    OpenAIRE

    Kappes, Ferdinand; Fahrer, Jörg; Khodadoust, Michael A.; Tabbert, Anja; Strasser, Christine; Mor-Vaknin, Nirit; Moreno-Villanueva, María; Bürkle, Alexander; Markovitz, David M; May, Elisa

    2008-01-01

    DEK is a nuclear phosphoprotein implicated in oncogenesis and autoimmunity and a major component of metazoan chromatin. The intracellular cues that control the binding of DEK to DNA and its pleiotropic functions in DNA- and RNA-dependent processes have remained mainly elusive so far. Our recent finding that the phosphorylation status of DEK is altered during death receptor-mediated apoptosis suggested a potential involvement of DEK in stress signaling. In this study, we show that in cells com...

  10. Positive selection of Caenorhabditis elegans mutants with increased stress resistance and longevity.

    OpenAIRE

    Manuel J. Muñoz; Donald L Riddle

    2003-01-01

    We developed selective conditions for long-lived mutants of the nematode Caenorhabditis elegans by subjecting the first larval stage (L1) to thermal stress at 30 degrees for 7 days. The surviving larvae developed to fertile adults after the temperature was shifted to 15 degrees. A total of one million F(2) progeny and a half million F(3) progeny of ethyl-methanesulfonate-mutagenized animals were treated in three separate experiments. Among the 81 putative mutants that recovered and matured to...

  11. Oxidative stress resistance genes contribute to the pathogenic potential of the anaerobic protozoan parasite, Entamoeba histolytica

    OpenAIRE

    Rastew, Elena; Vicente, João B.; Singh, Upinder

    2012-01-01

    The protozoan parasite, Entamoeba histolytica, invades the host colon causing significant tissue destruction and inflammation. Upon host infection, the parasite is confronted with reactive oxygen and nitrogen species (ROS/RNS) that cause large-scale changes in gene expression profiles, which likely support the parasite’s adaptation to the host environment. We have previously identified oxidative and nitrosative stress responsive genes using whole-genome expression profiling. Functional studie...

  12. Reproductive arrest and stress resistance in winter-acclimated Drosophila suzukii.

    Science.gov (United States)

    Toxopeus, Jantina; Jakobs, Ruth; Ferguson, Laura V; Gariepy, Tara D; Sinclair, Brent J

    2016-06-01

    Overwintering insects must survive the multiple-stress environment of winter, which includes low temperatures, reduced food and water availability, and cold-active pathogens. Many insects overwinter in diapause, a developmental arrest associated with high stress tolerance. Drosophila suzukii (Diptera: Drosophilidae), spotted wing drosophila, is an invasive agricultural pest worldwide. Its ability to overwinter and therefore establish in temperate regions could have severe implications for fruit crop industries. We demonstrate here that laboratory populations of Canadian D. suzukii larvae reared under short-day, low temperature, conditions develop into dark 'winter morph' adults similar to those reported globally from field captures, and observed by us in southern Ontario, Canada. These winter-acclimated adults have delayed reproductive maturity, enhanced cold tolerance, and can remain active at low temperatures, although they do not have the increased desiccation tolerance or survival of fungal pathogen challenges that might be expected from a more heavily melanised cuticle. Winter-acclimated female D. suzukii have underdeveloped ovaries and altered transcript levels of several genes associated with reproduction and stress. While superficially indicative of reproductive diapause, the delayed reproductive maturity of winter-acclimated D. suzukii appears to be temperature-dependent, not regulated by photoperiod, and is thus unlikely to be 'true' diapause. The traits of this 'winter morph', however, likely facilitate overwintering in southern Canada, and have probably contributed to the global success of this fly as an invasive species. PMID:27039032

  13. Folic acid supplementation at lower doses increases oxidative stress resistance and longevity in Caenorhabditis elegans.

    Science.gov (United States)

    Rathor, Laxmi; Akhoon, Bashir Akhlaq; Pandey, Swapnil; Srivastava, Swati; Pandey, Rakesh

    2015-12-01

    Folic acid (FA) is an essential nutrient that the human body needs but cannot be synthesized on its own. Fortified foods and plant food sources such as green leafy vegetables, beans, fruits, and juices are good sources of FA to meet the daily requirements of the body. The aim was to evaluate the effect of dietary FA levels on the longevity of well-known experimental aging model Caenorhabditis elegans. Here, we show for first time that FA extends organism life span and causes a delay in aging. We observed that FA inhibits mechanistic target of rapamycin (mTOR) and insulin/insulin growth factor 1 (IGF-1) signaling pathways to control both oxidative stress levels and life span. The expression levels of stress- and life span-relevant gerontogenes, viz. daf-16, skn-1, and sir. 2.1, and oxidative enzymes, such as glutathione S-transferase 4 (GST-4) and superoxide dismutase 3 (SOD-3), were also found to be highly enhanced to attenuate the intracellular reactive oxygen species (ROS) damage and to delay the aging process. Our study promotes the use of FA to mitigate abiotic stresses and other aging-related ailments.

  14. Mechanism of Different Stereoisomeric Astaxanthin in Resistance to Oxidative Stress in Caenorhabditis elegans.

    Science.gov (United States)

    Liu, Xiaojuan; Luo, Qingxin; Cao, Yong; Goulette, Timothy; Liu, Xin; Xiao, Hang

    2016-09-01

    As a potent antioxidant in human diet, astaxanthin (AST) may play important roles in alleviating oxidative stress-driven adverse physiological effects. This study examined the effects of different stereoisomers of AST in protecting Caenorhabditis elegans from chemically induced oxidative stress. Three stereoisomers of AST investigated herein included 3S,3´S (S) AST, 3R,3´R (R) AST, and a statistical mixture (S: meso: R = 1:2:1) (M) AST. Under paraquat-induced oxidative conditions, all three types of AST significantly enhanced survival rate of C. elegans. The accumulation levels of ROS in the worms were reduced by 40.12%, 30.05%, and 22.04% by S, R, and M AST, respectively (P < 0.05). Compared with R and M AST, S significantly enhanced the expression levels of SOD-3. The results of RNA-Seq analysis demonstrated that AST protected C. elegans from oxidative damage potentially by modulating genes involved in the insulin/insulin-like growth factor (IGF) signaling (IIS) pathway and the oxidoreductase system. It is noteworthy that different stereoisomers of AST showed different effects on the expression levels of various genes related with oxidative stress. This study revealed important information on the in vivo antioxidative effects of AST stereoisomers, which might provide useful information for better utilization of AST.

  15. Effect of sodium salicylate on oxidative stress andinsulinresistanceinducedbyfreefattyacids

    Institute of Scientific and Technical Information of China (English)

    Bing He; Sheng Zhao; Wei Zhang; Yan Li; Ping Han

    2010-01-01

    BACKGROUND: It has been reported that high-dose salicy-lates improve free fatty acids (FFAs)-induced insulin resistance andβ-cell dysfunction in vitro, but the mechanism remains uncertain. In insulin-resistant rats, we found that the supplementation of sodium salicylate is associated with a reduction of plasma malondialdehyde (MDA), a marker of oxidative stress. Few studies have investigated the effects of salicylates on oxidative stress levels in insulin-resistant animal models. This study aimed to assess the effect of sodium salicylate on insulin sensitivity and to explore the potential mechanism by which it improves hepatic and peripheral insulin resistance. METHODS: Intralipid+heparin (IH), saline (SAL), or intralipid+heparin+sodium salicylate (IHS) were separately infused for 7 hours in normal Wistar rats. During the last 2 hours of the infusion, hyperinsulinemic-euglycemic clamping was performed with [6-3H] glucose tracer. Plasma glucose was measured using the glucose oxygenase method. Plasma insulin and C-peptide were determined by radioimmunoassay. MDA levels and glutathione peroxidase (GSH-PX) activity in the liver and skeletal muscle were measured with colorimetric kits. RESULTS: Compared with infusion of SAL, IH infusion increased hepatic glucose production (HGP), and decreased glucose utilization (GU) (P CONCLUSIONS: Short-term elevation of fatty acids induces insulin resistance by enhancing oxidative stress levels in the liver and muscle. The administration of the anti-inlfammatory drug sodium salicylate reduces the degree of oxidative stress, therefore improving hepatic and peripheral insulin resistance. IKK-β and NF-κB provide potential pathogenic links to oxidative stress.

  16. Salivary a-amylase protects enamel surface against acid induced softening

    DEFF Research Database (Denmark)

    Lazovic, Maja Bruvo; Moe, Dennis; Kirkeby, Svend;

    -TOF mass fingerprinting following trypsin digestion. Each persistent peak in the HPLC chromatograms was related to the protective effect against acid-induced enamel softening obtained by the corresponding saliva sample by multiple regression analysis. Results: One peak identified as a-amylase had...... an explanatory power of 39% in the analysis with high concentrations being most protective (pamylase on protective effect to 65...

  17. Victim-Offender Relationship Status Moderates the Relationships of Peritraumatic Emotional Responses, Active Resistance, and Posttraumatic Stress Symptomatology in Female Rape Survivors.

    Science.gov (United States)

    Feinstein, Brian A; Humphreys, Kathryn L; Bovin, Michelle J; Marx, Brian P; Resick, Patricia A

    2011-06-01

    This study examined whether the level of victim-offender relationship (VOR) moderated the relationship between peritraumatic fear and active resistance as well as the relationship between peritraumatic fear and posttraumatic stress symptom severity in a community sample of female rape survivors. One hundred thirty-five participants were interviewed about their emotional and behavioral responses during the rape and assessed for posttraumatic stress symptomatology within one month of the assault. Results indicated that peritraumatic fear was positively associated with active resistance, but only among survivors of acquaintance rape. Additionally, peritraumatic fear was positively associated with posttraumatic stress symptom severity, but only among survivors of intimate partner rape. These results suggest that VOR may be an important contextual factor that influences emotional and behavioral responses during rape as well as posttraumatic stress symptomatology in its aftermath. PMID:21731797

  18. Staphylococcus aureus CymR Is a New Thiol-based Oxidation-sensing Regulator of Stress Resistance and Oxidative Response

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Quanjiang; Zhang, Liang; Sun, Fei; Deng, Xin; Liang, Haihua; Bae, Taeok; He, Chuan (Indiana-Med); (UC)

    2014-10-02

    As a human pathogen, Staphylococcus aureus must cope with oxidative stress generated by the human immune system. Here, we report that CymR utilizes its sole Cys-25 to sense oxidative stress. Oxidation followed by thiolation of this cysteine residue leads to dissociation of CymR from its cognate promoter DNA. In contrast, the DNA binding of the CymRC25S mutant was insensitive to oxidation and thiolation, suggesting that CymR senses oxidative stress through oxidation of its sole cysteine to form a mixed disulfide with low molecular weight thiols. The determined crystal structures of the reduced and oxidized forms of CymR revealed that Cys-25 is oxidized to Cys-25-SOH in the presence of H{sub 2}O{sub 2}. Deletion of cymR reduced the resistance of S. aureus to oxidative stresses, and the resistance was restored by expressing a C25S mutant copy of cymR. In a C25S substitution mutant, the expression of two genes, tcyP and mccB, was constitutively repressed and did not respond to hydrogen peroxide stress, whereas the expression of the genes were highly induced under oxidative stress in a wild-type strain, indicating the critical role of Cys-25 in redox signaling in vivo. Thus, CymR is another master regulator that senses oxidative stress and connects stress responses to virulence regulation in S. aureus.

  19. Two-dimensional Electrophoresis Analysis of Proteins in Response to Cold Stress in Extremely Cold-resistant Winter Wheat Dongnongdongmai 1 Tillering Nodes

    Institute of Scientific and Technical Information of China (English)

    Cang Jing; Yu Jing; Liu Li-jie; Yang Yang; Cui Hong; Hao Zai-bin; Li Zhuo-fu

    2012-01-01

    The overwintering survival ratio of the cultivar Dongnongdongmai 1 with strong cold-resistance in paramos of Heilongjiang Province in China are over 85%. The tillering nodes are the most important organs for overwintering survival of winter wheat, because there are more substances associated with cold resistance in tillering nodes than those in leaves and roots. Proteins in the tillering nodes of the cold-resistant cultivar Dongnongdongmai 1 grown under field conditions with or without any lowtemperature stress were analyzed by 2-dimensional electrophoresis and identified by mass spectrometry. In the range of pH 4-7, the expression of 37 proteins showed obvious difference (±more than two fold) in the proteomic maps of cold-stressed and non-stressed tillering nodes, including a new protein spot. All proteins exhibiting the difference in expression were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, followed by a database search for protein identification and function prediction. Five groups of proteins were confirmed, namely stress-related proteins (22%), metabolism-associated proteins (35%), and signaling molecules (24%), cell wall-binding proteins (5%), unclear proteins (14%). This indicated that tillering node cells supported the energy requirements of plant growth and stress resistance by signal transduction adapting to metabolism and structure.

  20. Development and characterization of a hydrogen peroxide-resistant cholangiocyte cell line: A novel model of oxidative stress-related cholangiocarcinoma genesis

    Energy Technology Data Exchange (ETDEWEB)

    Thanan, Raynoo [Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Techasen, Anchalee [Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Faculty of Associated Medical Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Hou, Bo [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie 514-8507 (Japan); Jamnongkan, Wassana; Armartmuntree, Napat [Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Yongvanit, Puangrat, E-mail: puangrat@kku.ac.th [Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Murata, Mariko, E-mail: mmurata@doc.medic.mie-u.ac.jp [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie 514-8507 (Japan)

    2015-08-14

    Oxidative stress is a cause of inflammation–related diseases, including cancers. Cholangiocarcinoma is a liver cancer with bile duct epithelial cell phenotypes. Our previous studies in animal and human models indicated that oxidative stress is a major cause of cholangiocarcinoma development. Hydrogen peroxide (H{sub 2}O{sub 2}) can generate hydroxyl radicals, which damage lipids, proteins, and nucleic acids, leading to cell death. However, some cells can survive by adapting to oxidative stress conditions, and selective clonal expansion of these resistant cells would be involved in oxidative stress-related carcinogenesis. The present study aimed to establish H{sub 2}O{sub 2}-resistant cell line from an immortal cholangiocyte cell line (MMNK1) by chronic treatment with low-concentration H{sub 2}O{sub 2} (25 μM). After 72 days of induction, H{sub 2}O{sub 2}-resistant cell lines (ox-MMNK1-L) were obtained. The ox-MMNK1-L cell line showed H{sub 2}O{sub 2}-resistant properties, increasing the expression of the anti-oxidant genes catalase (CAT), superoxide dismutase-1 (SOD1), superoxide dismutase-2 (SOD2), and superoxide dismutase-3 (SOD3) and the enzyme activities of CAT and intracellular SODs. Furthermore, the resistant cells showed increased expression levels of an epigenetics-related gene, DNA methyltransferase-1 (DNMT1), when compared to the parental cells. Interestingly, the ox-MMNK1-L cell line had a significantly higher cell proliferation rate than the MMNK1 normal cell line. Moreover, ox-MMNK1-L cells showed pseudopodia formation and the loss of cell-to-cell adhesion (multi-layers) under additional oxidative stress (100 μM H{sub 2}O{sub 2}). These findings suggest that H{sub 2}O{sub 2}-resistant cells can be used as a model of oxidative stress-related cholangiocarcinoma genesis through molecular changes such as alteration of gene expression and epigenetic changes. - Highlights: • An H{sub 2}O{sub 2}-resistant ox-MMNK1-L cells was established from

  1. Victim-Offender Relationship Status Moderates the Relationships of Peritraumatic Emotional Responses, Active Resistance, and Posttraumatic Stress Symptomatology in Female Rape Survivors

    OpenAIRE

    Feinstein, Brian A.; Humphreys, Kathryn L.; Bovin, Michelle J.; Marx, Brian P.; Resick, Patricia A.

    2011-01-01

    This study examined whether the level of victim-offender relationship (VOR) moderated the relationship between peritraumatic fear and active resistance as well as the relationship between peritraumatic fear and posttraumatic stress symptom severity in a community sample of female rape survivors. One hundred thirty-five participants were interviewed about their emotional and behavioral responses during the rape and assessed for posttraumatic stress symptomatology within one month of the assaul...

  2. Enriching the drinking water of rats with extracts of Salvia officinalis and Thymus vulgaris increases their resistance to oxidative stress.

    Science.gov (United States)

    Horváthová, Eva; Srančíková, Annamária; Regendová-Sedláčková, Eva; Melušová, Martina; Meluš, Vladimír; Netriová, Jana; Krajčovičová, Zdenka; Slameňová, Darina; Pastorek, Michal; Kozics, Katarína

    2016-01-01

    Nature is an attractive source of therapeutic compounds. In comparison to the artificial drugs, natural compounds cause less adverse side effects and are suitable for current molecularly oriented approaches to drug development and their mutual combining. Medicinal plants represent one of the most available remedy against various diseases. Proper examples are Salvia officinalis L. and Thymus vulgaris L. which are known aromatic medicinal plants. They are very popular and frequently used in many countries. The molecular mechanism of their biological activity has not yet been fully understood. The aim of this study was to ascertain if liver cells of experimental animals drinking extracts of sage or thyme will manifest increased resistance against oxidative stress. Adult Sprague-Dawley rats were divided into seven groups. They drank sage or thyme extracts for 2 weeks. At the end of the drinking period, blood samples were collected for determination of liver biochemical parameters and hepatocytes were isolated to analyze (i) oxidatively generated DNA damage (conventional and modified comet assay), (ii) activities of antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GPx)] and (iii) content of glutathione. Intake of sage and thyme had no effect either on the basal level of DNA damage or on the activity of SOD in rat hepatocytes and did not change the biochemical parameters of blood plasma. Simultaneously, the activity of GPx was significantly increased and the level of DNA damage induced by oxidants was decreased. Moreover, sage extract was able to start up the antioxidant protection expressed by increased content of glutathione. Our results indicate that the consumption of S.officinalis and T.vulgaris extracts positively affects resistency of rat liver cells against oxidative stress and may have hepatoprotective potential.

  3. Acute dyskerin depletion triggers cellular senescence and renders osteosarcoma cells resistant to genotoxic stress-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ping; Mobasher, Maral E.; Alawi, Faizan, E-mail: falawi@upenn.edu

    2014-04-18

    Highlights: • Dyskerin depletion triggers cellular senescence in U2OS osteosarcoma cells. • Dyskerin-depleted cells are resistant to apoptosis induced by genotoxic stress. • Chromatin relaxation sensitizes dyskerin-depleted cells to apoptosis. - Abstract: Dyskerin is a conserved, nucleolar RNA-binding protein implicated in an increasing array of fundamental cellular processes. Germline mutation in the dyskerin gene (DKC1) is the cause of X-linked dyskeratosis congenita (DC). Conversely, wild-type dyskerin is overexpressed in sporadic cancers, and high-levels may be associated with poor prognosis. It was previously reported that acute loss of dyskerin function via siRNA-mediated depletion slowed the proliferation of transformed cell lines. However, the mechanisms remained unclear. Using human U2OS osteosarcoma cells, we show that siRNA-mediated dyskerin depletion induced cellular senescence as evidenced by proliferative arrest, senescence-associated heterochromatinization and a senescence-associated molecular profile. Senescence can render cells resistant to apoptosis. Conversely, chromatin relaxation can reverse the repressive effects of senescence-associated heterochromatinization on apoptosis. To this end, genotoxic stress-induced apoptosis was suppressed in dyskerin-depleted cells. In contrast, agents that induce chromatin relaxation, including histone deacetylase inhibitors and the DNA intercalator chloroquine, sensitized dyskerin-depleted cells to apoptosis. Dyskerin is a core component of the telomerase complex and plays an important role in telomere homeostasis. Defective telomere maintenance resulting in premature senescence is thought to primarily underlie the pathogenesis of X-linked DC. Since U2OS cells are telomerase-negative, this leads us to conclude that loss of dyskerin function can also induce cellular senescence via mechanisms independent of telomere shortening.

  4. Cafeteria diet induces obesity and insulin resistance associated with oxidative stress but not with inflammation: improvement by dietary supplementation with a melon superoxide dismutase.

    Science.gov (United States)

    Carillon, Julie; Romain, Cindy; Bardy, Guillaume; Fouret, Gilles; Feillet-Coudray, Christine; Gaillet, Sylvie; Lacan, Dominique; Cristol, Jean-Paul; Rouanet, Jean-Max

    2013-12-01

    Oxidative stress is involved in obesity. However, dietary antioxidants could prevent oxidative stress-induced damage. We have previously shown the preventive effects of a melon superoxide dismutase (SODB) on oxidative stress. However, the mechanism of action of SODB is still unknown. Here, we evaluated the effects of a 1-month curative supplementation with SODB on the liver of obese hamsters. Golden Syrian hamsters received either a standard diet or a cafeteria diet composed of high-fat, high-sugar, and high-salt supermarket products, for 15 weeks. This diet resulted in insulin resistance and in increased oxidative stress in the liver. However, inflammatory markers (IL-6, TNF-α, and NF-κB) were not enhanced and no liver steatosis was detected, although these are usually described in obesity-induced insulin resistance models. After the 1-month supplementation with SODB, body weight and insulin resistance induced by the cafeteria diet were reduced and hepatic oxidative stress was corrected. This could be due to the increased expression of the liver antioxidant defense proteins (manganese and copper/zinc superoxide dismutase, catalase, and glutathione peroxidase). Even though no inflammation was detected in the obese hamsters, inflammatory markers were decreased after SODB supplementation, probably through the reduction of oxidative stress. These findings suggest for the first time that SODB could exert its antioxidant properties by inducing the endogenous antioxidant defense. The mechanisms underlying this induction need to be further investigated.

  5. SIRT1 attenuates palmitate-induced endoplasmic reticulum stress and insulin resistance in HepG2 cells via induction of oxygen-regulated protein 150

    Science.gov (United States)

    Jung, T.W.; Lee, K.T.; Lee, M.W.; Ka, K.H.

    2012-01-01

    Endoplasmic reticulum (ER) stress has been implicated in the pathology of type 2 diabetes mellitus (T2DM). Although SIRT1 has a therapeutic effect on T2DM, the mechanisms by which SIRT1 ameliorates insulin resistance (IR) remain unclear. In this study, we investigated the impact of SIRT1 on palmitate-induced ER stress in HepG2 cells and its underlying signal pathway. Treatment with resveratrol, a SIRT1 activator significantly inhibited palmitate-induced ER stress, leading to the protection against palmitate-induced ER stress and insulin resistance. Resveratrol and SIRT1 overexpression induced the expression of oxygen-regulated protein (ORP) 150 in HepG2 cells. Forkhead box O1 (FOXO1) was involved in the regulation of ORP150 expression because suppression of FOXO1 inhibited the induction of ORP150 by SIRT1. Our results indicate a novel mechanism by which SIRT1 regulates ER stress by overexpression of ORP150, and suggest that SIRT1 ameliorates palmitate-induced insulin resistance in HepG2 cells via regulation of ER stress.

  6. Cafeteria diet induces obesity and insulin resistance associated with oxidative stress but not with inflammation: improvement by dietary supplementation with a melon superoxide dismutase.

    Science.gov (United States)

    Carillon, Julie; Romain, Cindy; Bardy, Guillaume; Fouret, Gilles; Feillet-Coudray, Christine; Gaillet, Sylvie; Lacan, Dominique; Cristol, Jean-Paul; Rouanet, Jean-Max

    2013-12-01

    Oxidative stress is involved in obesity. However, dietary antioxidants could prevent oxidative stress-induced damage. We have previously shown the preventive effects of a melon superoxide dismutase (SODB) on oxidative stress. However, the mechanism of action of SODB is still unknown. Here, we evaluated the effects of a 1-month curative supplementation with SODB on the liver of obese hamsters. Golden Syrian hamsters received either a standard diet or a cafeteria diet composed of high-fat, high-sugar, and high-salt supermarket products, for 15 weeks. This diet resulted in insulin resistance and in increased oxidative stress in the liver. However, inflammatory markers (IL-6, TNF-α, and NF-κB) were not enhanced and no liver steatosis was detected, although these are usually described in obesity-induced insulin resistance models. After the 1-month supplementation with SODB, body weight and insulin resistance induced by the cafeteria diet were reduced and hepatic oxidative stress was corrected. This could be due to the increased expression of the liver antioxidant defense proteins (manganese and copper/zinc superoxide dismutase, catalase, and glutathione peroxidase). Even though no inflammation was detected in the obese hamsters, inflammatory markers were decreased after SODB supplementation, probably through the reduction of oxidative stress. These findings suggest for the first time that SODB could exert its antioxidant properties by inducing the endogenous antioxidant defense. The mechanisms underlying this induction need to be further investigated. PMID:23792771

  7. Effects of Different Levels of Water Stress on Leaf Water Potential, Stomatal Resistance, Protein and Chlorophyll Content and Certain Anti-oxidative Enzymes in Tomato Plants

    Institute of Scientific and Technical Information of China (English)

    Hatem Zgallai; Kathy Steppe; Raoul Lemeur

    2006-01-01

    A greenhouse experiment was performed in order to investigate the effects of different levels of water stress on leaf water potential (ψw), stomatal resistance (rs), protein content and chlorophyll (Chi) content of tomato plants (Lycopersicon esculentum Mill. cv. Nikita). Water stress was induced by adding polyethylene glycol (PEG 6 000) to the nutrient solution to reduce the osmotic potential (ψs). We investigated the behavior of anti-oxidant enzymes, such as catalase (CAT) and superoxide dismutase (SOD), during the development of water stress. Moderate and severe water stress (i.e.ψs= -0.51 and -1.22 MPa, respectively) caused a decrease in ψw for all treated (water-stressed) plants compared with control plants, with the reduction being more pronounced for severely stressed plants. In addition, rs was significantly affected by the induced water stress and a decrease in leaf soluble proteins and Chi content was observed. Whereas CAT activity remained constant, SOD activity was increased in water-stressed plants compared with unstressed plants. These results indicate the possible role of SOD as an anti-oxidant protector system for plants under water stress conditions. Moreover, it suggests the possibility of using this enzyme as an additional screening criterion for detecting water stress in plants.

  8. Stress resistance strategy in an arid land shrub: interactions between developmental instability and fractal dimention

    Science.gov (United States)

    Escos, J.; Alados, C.L.; Pugnaire, F. I.; Puigdefábregas, J.; Emlen, J.

    2000-01-01

    This paper investigates allocation of energy to mechanisms that generate and preserve architectural forms (i.e. developmental stability, complexity of branching patterns) and productivity (growth and reproduction) in response to environmental disturbances (i.e. grazing and resource availability). The statistical error in translational symmetry was used to detect random intra-individual variability during development. This can be thought of as a measure of developmental instability caused by stress. Additionally, we use changes in fractal complexity and shoot distribution of branch structures as an alternate indicator of stress. These methods were applied to Anthyllis cytisoides L., a semi-arid environment shrub, to ascertain the effect of grazing and slope exposure on developmental traits in a 2×2 factorial design. The results show that A. cytisoidesmaintains developmental stability at the expense of productivity. Anthyllis cytisoides was developmentally more stable when grazed and when on south-facing, as opposed to north-facing slopes. On the contrary, shoot length, leaf area, fractal dimension and reproductive-to-vegetative allocation ratio were larger in north- than in south-facing slopes. As a consequence, under extreme xeric conditions, shrub mortality increased in north-facing slopes, especially when not grazed. The removal of transpiring area and the reduction of plant competition favoured developmental stability and survival in grazed plants. Differences between grazed and ungrazed plants were most evident in more mesic (north-facing) areas.

  9. Gene Networks in the Wild: Identifying Transcriptional Modules that Mediate Coral Resistance to Experimental Heat Stress.

    Science.gov (United States)

    Rose, Noah H; Seneca, Francois O; Palumbi, Stephen R

    2015-12-28

    Organisms respond to environmental variation partly through changes in gene expression, which underlie both homeostatic and acclimatory responses to environmental stress. In some cases, so many genes change in expression in response to different influences that understanding expression patterns for all these individual genes becomes difficult. To reduce this problem, we use a systems genetics approach to show that variation in the expression of thousands of genes of reef-building corals can be explained as variation in the expression of a small number of coexpressed "modules." Modules were often enriched for specific cellular functions and varied predictably among individuals, experimental treatments, and physiological state. We describe two transcriptional modules for which expression levels immediately after heat stress predict bleaching a day later. One of these early "bleaching modules" is enriched for sequence-specific DNA-binding proteins, particularly E26 transformation-specific (ETS)-family transcription factors. The other module is enriched for extracellular matrix proteins. These classes of bleaching response genes are clear in the modular gene expression analysis we conduct but are much more difficult to discern in single gene analyses. Furthermore, the ETS-family module shows repeated differences in expression among coral colonies grown in the same common garden environment, suggesting a heritable genetic or epigenetic basis for these expression polymorphisms. This finding suggests that these corals harbor high levels of gene-network variation, which could facilitate rapid evolution in the face of environmental change.

  10. Gene Networks in the Wild: Identifying Transcriptional Modules that Mediate Coral Resistance to Experimental Heat Stress.

    Science.gov (United States)

    Rose, Noah H; Seneca, Francois O; Palumbi, Stephen R

    2016-01-01

    Organisms respond to environmental variation partly through changes in gene expression, which underlie both homeostatic and acclimatory responses to environmental stress. In some cases, so many genes change in expression in response to different influences that understanding expression patterns for all these individual genes becomes difficult. To reduce this problem, we use a systems genetics approach to show that variation in the expression of thousands of genes of reef-building corals can be explained as variation in the expression of a small number of coexpressed "modules." Modules were often enriched for specific cellular functions and varied predictably among individuals, experimental treatments, and physiological state. We describe two transcriptional modules for which expression levels immediately after heat stress predict bleaching a day later. One of these early "bleaching modules" is enriched for sequence-specific DNA-binding proteins, particularly E26 transformation-specific (ETS)-family transcription factors. The other module is enriched for extracellular matrix proteins. These classes of bleaching response genes are clear in the modular gene expression analysis we conduct but are much more difficult to discern in single gene analyses. Furthermore, the ETS-family module shows repeated differences in expression among coral colonies grown in the same common garden environment, suggesting a heritable genetic or epigenetic basis for these expression polymorphisms. This finding suggests that these corals harbor high levels of gene-network variation, which could facilitate rapid evolution in the face of environmental change. PMID:26710855

  11. Fungal Elicitor MoHrip2 Induces Disease Resistance in Rice Leaves, Triggering Stress-Related Pathways

    Science.gov (United States)

    Khan, Najeeb Ullah; Liu, Mengjie; Yang, Xiufen; Qiu, Dewen

    2016-01-01

    MoHrip2 Magnaporthe oryzae hypersensitive protein 2 is an elicitor protein of rice blast fungus M. oryzae. Rice seedlings treated with MoHrip2 have shown an induced resistance to rice blast. To elucidate the mechanism underlying this MoHrip2 elicitation in rice, we used differential-display 2-D gel electrophoresis and qRT-PCR to assess the differential expression among the total proteins extracted from rice leaves at 24 h after treatment with MoHrip2 and buffer as a control. Among ~1000 protein spots detected on each gel, 10 proteins were newly induced, 4 were up-regulated, and 3 were down-regulated in MoHrip2-treated samples compared with the buffer control. Seventeen differentially expressed proteins were detected using MS/MS analysis and categorized into six groups according to their putative function: defense-related transcriptional factors, signal transduction-related proteins, reactive oxygen species (ROS) production, programmed cell death (PCD), defense-related proteins, and photosynthesis and energy-related proteins. The qPCR results (relative expression level of genes) further supported the differential expression of proteins in MoHrip2-treated rice leaves identified with 2D-gel, suggesting that MoHrip2 triggers an early defense response in rice leaves via stress-related pathways, and the results provide evidence for elicitor-induced resistance at the protein level. PMID:27348754

  12. Fungal Elicitor MoHrip2 Induces Disease Resistance in Rice Leaves, Triggering Stress-Related Pathways.

    Science.gov (United States)

    Khan, Najeeb Ullah; Liu, Mengjie; Yang, Xiufen; Qiu, Dewen

    2016-01-01

    MoHrip2 Magnaporthe oryzae hypersensitive protein 2 is an elicitor protein of rice blast fungus M. oryzae. Rice seedlings treated with MoHrip2 have shown an induced resistance to rice blast. To elucidate the mechanism underlying this MoHrip2 elicitation in rice, we used differential-display 2-D gel electrophoresis and qRT-PCR to assess the differential expression among the total proteins extracted from rice leaves at 24 h after treatment with MoHrip2 and buffer as a control. Among ~1000 protein spots detected on each gel, 10 proteins were newly induced, 4 were up-regulated, and 3 were down-regulated in MoHrip2-treated samples compared with the buffer control. Seventeen differentially expressed proteins were detected using MS/MS analysis and categorized into six groups according to their putative function: defense-related transcriptional factors, signal transduction-related proteins, reactive oxygen species (ROS) production, programmed cell death (PCD), defense-related proteins, and photosynthesis and energy-related proteins. The qPCR results (relative expression level of genes) further supported the differential expression of proteins in MoHrip2-treated rice leaves identified with 2D-gel, suggesting that MoHrip2 triggers an early defense response in rice leaves via stress-related pathways, and the results provide evidence for elicitor-induced resistance at the protein level. PMID:27348754

  13. Immune response, stress resistance and bacterial challenge in juvenile rainbow trouts Oncorhynchus mykiss fed diets containing chitosan-oligosaccharides

    Directory of Open Access Journals (Sweden)

    Lin LUO, Xuefeng CAI, Chuan HE, Min XUE, Xiufeng WU , Haining CAO

    2009-12-01

    Full Text Available Effects of dietary supplementation of chitosan-oligosaccharides (COS on the growth performance, immune response, stress resistance, and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied. Four experimental diets containing 0, 20, 40, or 60 mg/kg COS (COS0, COS20, COS40, and COS60, respectively were fed to juvenile rainbow trout (initial weight = 5.2 ± 0.3 g for 8 weeks. By the end of the feeding trial, representative groups of fish from each dietary treatment were challenged with stressor (30 sec air exposure and pathogen exposure (intraperitoneal injection with Aeromonas hydrophila. Results showed that supplementation of COS in diets did not affect production performance and body composition of rainbow trout. However, fish fed the COS40 diet demonstrated improved phagocytic activities, respiratory burst activities and decreased serum cortisol level. Additionally, survival following A. hydrophila challenge was significant higher among fish fed the COS-supplemented feeds, although there was no difference based on the level of supplementation. The present study suggests that COS can be used as an immuno-stimulant in rainbow trout feeds [Current Zoology 55 (6: 416– 422, 2009].

  14. Influence of uniconazole on freezing stress resistance of cold acclimating (S. commersonii) and of non acclimating (S. tuberosum) potato species

    Energy Technology Data Exchange (ETDEWEB)

    Saavedra, J.A.; Palta, J.P.; Stang, E.J. (Univ. of Wisconsin, Madison (United States))

    1991-05-01

    Uniconazole (UCZ) is an effective growth suppressant of the group of triazoles. Triazoles have been used as fungicides (inhibiting sterol biosynthesis) or plant growth regulators (inhibiting gibberellin biosynthesis). Some reports suggest that triazoles can help to alleviate some environmental stresses, including SO{sub 2}, drought, and low and high temperatures. Using soil drench or foliar spray procedure the authors investigated the influence of UCZ 95-500 mg L{sup {minus}1} on freezing tolerance of leaf tissue. Freezing tolerance was evaluated 1-10 days following UCZ treatment by using electrolyte leakage method. They also measured internode length, chlorophyll content, and the size of palisade layer on treated leaves. The highest UCZ rate (500 mg L{sup {minus}1}) did not cause injury to the plants. Chlorophyll content and length of palisade cells increased by 30 and 14%, respectively, in the treated leaves. The internode length was suppressed in 22% by UCZ. Thus UCZ was effective in dwarfing the plants. However, no dramatic effects were found on the freezing stress resistance in both potato species.

  15. A homologue of vitamin K epoxide reductase in Solanum lycopersicum is involved in resistance to osmotic stress.

    Science.gov (United States)

    Yu, Zhi-Bo; Yang, Xiao-Jian; Du, Jia-Jia; Wan, Chun-Mei; Xu, Jia-Ning; Wang, Wen-Jun; Feng, Yue-Guang; Wang, Xiao-Yun

    2016-03-01

    Vitamin K epoxide reductase (VKOR) exists widely in the chloroplasts of higher plants and plays important roles in redox regulation. However, investigations of plant VKOR function have primarily focused on VKOR from Arabidopsis, and knowledge concerning this function is therefore quite limited. In this study, Solanum lycopersicum was used to study the function of VKOR. Transcription level analysis revealed that SlVKOR (S. lycopersicum VKOR) expression was upregulated by salt or drought stress. To further investigate the function of SlVKOR in plants, we generated sense and antisense transgenic S. lycopersicum homozygotes at T2 generation plants. Compared with wild-type (WT) plants, the leaf disks of the SlVKOR overexpression plants retained a much higher percentage of chlorophyll after salt or drought treatment, whereas the antisense transgenic plants displayed an opposite response. The overexpressed plants displayed lower levels of H2O2 and superoxide anion radical (O2(·-)) than WT plants, whereas antisense plants accumulated considerably more H2O2 and O2(·-). The activities of reactive oxygen scavenger enzymes, including superoxide dismutase, peroxidase, ascorbate peroxidase and catalase, were consistent with the accumulation of reactive oxygen species. Based on these results, we suggest that SlVKOR is involved in resistance to salt or drought stress. PMID:26294083

  16. Arabidopsis COPPER MODIFIED RESISTANCE1/PATRONUS1 is essential for growth adaptation to stress and required for mitotic onset control.

    Science.gov (United States)

    Juraniec, Michal; Heyman, Jefri; Schubert, Veit; Salis, Pietrino; De Veylder, Lieven; Verbruggen, Nathalie

    2016-01-01

    The mitotic checkpoint (MC) guards faithful sister chromatid segregation by monitoring the attachment of spindle microtubules to the kinetochores. When chromosome attachment errors are detected, MC delays the metaphase-to-anaphase transition through the inhibition of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase. In contrast to yeast and mammals, our knowledge on the proteins involved in MC in plants is scarce. Transient synchronization of root tips as well as promoter-reporter gene fusions were performed to analyze temporal and spatial expression of COPPER MODIFIED RESISTANCE1/PATRONUS1 (CMR1/PANS1) in developing Arabidopsis thaliana seedlings. Functional analysis of the gene was carried out, including CYCB1;2 stability in CMR1/PANS1 knockout and overexpressor background as well as metaphase-anaphase chromosome status. CMR1/PANS1 is transcriptionally active during M phase. Its deficiency provokes premature cell cycle exit and in consequence a rapid consumption of the number of meristematic cells in particular under stress conditions that are known to affect spindle microtubules. Root growth impairment is correlated with a failure to delay the onset of anaphase, resulting in anaphase bridges and chromosome missegregation. CMR1/PANS1 overexpression stabilizes the mitotic CYCB1;2 protein. Likely, CMR1/PANS1 coordinates mitotic cell cycle progression by acting as an APC/C inhibitor and plays a key role in growth adaptation to stress.

  17. Arrhenius-Type Constitutive Model for High Temperature Flow Stress in a Nickel-Based Corrosion-Resistant Alloy

    Science.gov (United States)

    Wang, L.; Liu, F.; Cheng, J. J.; Zuo, Q.; Chen, C. F.

    2016-04-01

    Hot deformation behavior of Nickel-based corrosion-resistant alloy (N08028) was studied in compression tests conducted in the temperature range of 1050-1200 °C and the strain rate range of 0.001-1 s-1. The flow stress behavior and microstructural evolution were observed during the hot deformation process. The results show that the flow stress increases with deformation temperature decreasing and strain rate increasing, and that the deformation activation energy ( Q) is not a constant but increases with strain rate increasing at a given strain, which is closely related with dislocation movement. On this basis, a revised strain-dependent hyperbolic sine constitutive model was established, which considered that the "material constants" in the original model vary as functions of the strain and strain rate. The flow curves of N08028 alloy predicted by the proposed model are in good agreement with the experimental results, which indicates that the revised constitutive model can estimate precisely the flow curves of N08028 alloy.

  18. A natural formulation (imoviral™) increases macrophage resistance to LPS-induced oxidative and inflammatory stress in vitro.

    Science.gov (United States)

    Menghini, L; Leporini, L; Pintore, G; Ferrante, C; Recinella, L; Orlando, G; Vacca, M; Brunetti, L

    2014-01-01

    Imoviral™ is a natural product formulation containing a mixture of uncaria, shiitake and ribes extracts. All ingredients are recognized as antioxidant, anti-inflammatory agent and immunomodulant. In order to evaluate the rational basis of extract mixture as immunomodulatory agent, we tested the effect of Imoviral™ formulation on macrophage response to lipopolysaccharide (LPS)-induced stress. The effect was evaluated as variation of reactive oxygen species (ROS) and prostaglandin E2 (PGE2) production and as cytokine gene expression. The extract did not affect cell viability up to 250 μg/ml. Treatment with extract (10-150 μg/ml) reduced ROS and PGE2 production as well as IL-8 and TNF-α gene expression. A pre-treatment with extract blunted LPS-induced production of ROS and PGE2, markers of oxidative and inflammatory stress, as well as the gene expression of all cytokines tested, indicators, in vitro, of immune response activation. In conclusion, we demonstrated that Imoviral™ formulation could be a useful tool to modulate the immune function, reducing the oxidative and inflammatory markers related to bacterial attack. Experimental data suggest that Imoviral™ extract mixture could also represent a preventive pharmacological strategy to enhance cell resistance to bacterial infections. PMID:25620186

  19. Methicillin resistant Staphylococcus aureus adhesion to human umbilical vein endothelial cells demonstrates wall shear stress dependent behaviour

    Directory of Open Access Journals (Sweden)

    Martinuzzi Robert M

    2011-03-01

    Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA is an increasingly prevalent pathogen capable of causing severe vascular infections. The goal of this work was to investigate the role of shear stress in early adhesion events. Methods Human umbilical vein endothelial cells (HUVEC were exposed to MRSA for 15-60 minutes and shear stresses of 0-1.2 Pa in a parallel plate flow chamber system. Confocal microscopy stacks were captured and analyzed to assess the number of MRSA. Flow chamber parameters were validated using micro-particle image velocimetry (PIV and computational fluid dynamics modelling (CFD. Results Under static conditions, MRSA adhered to, and were internalized by, more than 80% of HUVEC at 15 minutes, and almost 100% of the cells at 1 hour. At 30 minutes, there was no change in the percent HUVEC infected between static and low flow (0.24 Pa, but a 15% decrease was seen at 1.2 Pa. The average number of MRSA per HUVEC decreased 22% between static and 0.24 Pa, and 37% between 0.24 Pa and 1.2 Pa. However, when corrected for changes in bacterial concentration near the surface due to flow, bacteria per area was shown to increase at 0.24 Pa compared to static, with a subsequent decline at 1.2 Pa. Conclusions This study demonstrates that MRSA adhesion to endothelial cells is strongly influenced by flow conditions and time, and that MSRA adhere in greater numbers to regions of low shear stress. These areas are common in arterial bifurcations, locations also susceptible to generation of atherosclerosis.

  20. Dietary nano-selenium relieves hypoxia stress and, improves immunity and disease resistance in the Chinese mitten crab (Eriocheir sinensis).

    Science.gov (United States)

    Qin, Fenju; Shi, Miaomiao; Yuan, Hongxia; Yuan, Linxi; Lu, Wenhao; Zhang, Jie; Tong, Jian; Song, Xuehong

    2016-07-01

    Hypoxia is a relevant physiological challenge for crab culture, and the hemolymph plays a crucial role in response to the hypoxia. In a 60 d feeding trial, Chinese mitten crabs (Eriocheir sinensis) fed a diet containing 0.2 mg/kg nano-selenium (nanoSe) showed a significantly increased weight gain rate (WGR) and a reduced feed coefficient (FC) compared to those fed diets with 0, 0.1, 0.4, 0.8, and 1.6 mg/kg nanoSe. Another 90 d feeding trial was conducted to determine the influence of dietary nanoSe on the immune response in juvenile Chinese mitten crabs kept under the condition of hypoxia. The results showed that hypoxia stress resulted in significantly increased hemocyte counts (THC, LGC, SGC, and HC), expression levels of the hemocyanin gene and protein, lactic acid level, and antioxidant capacity (T-AOC activities, SOD activities, GSH-Px and GSH content) in hemolymph supernatant. When these crabs were infected with Aeromonas hydrophila bacteria, hypoxia exposure increased mortality, but it was alleviated by a diet supplemented with 0.2 mg/kg nanoSe. The up-regulative effects of nanoSe (0.2 mg/kg) on antioxidant capacity, hemocyte counts, and hemocyanin expression under hypoxia exposure were further strengthened throughout, whereas lactic acid levels induced by hypoxia stress were restored. Thus, the observations in this study indicate that the level of dietary nanoSe is important in regulating immunity and disease resistance in crabs kept under hypoxia stress. PMID:27153751

  1. Grasshopper Lazarillo, a GPI-anchored Lipocalin, increases Drosophila longevity and stress resistance, and functionally replaces its secreted homolog NLaz.

    Science.gov (United States)

    Ruiz, Mario; Wicker-Thomas, Claude; Sanchez, Diego; Ganfornina, Maria D

    2012-10-01

    Lazarillo (Laz) is a glycosyl-phosphatidylinositol (GPI)-linked glycoprotein first characterized in the developing nervous system of the grasshopper Schistocerca americana. It belongs to the Lipocalins, a functionally diverse family of mostly secreted proteins. In this work we test whether the protective capacity known for Laz homologs in flies and vertebrates (NLaz, GLaz and ApoD) is evolutionarily conserved in grasshopper Laz, and can be exerted from the plasma membrane in a cell-autonomous manner. First we demonstrate that extracellular forms of Laz have autocrine and paracrine protecting effects for oxidative stress-challenged Drosophila S2 cells. Then we assay the effects of overexpressing GPI-linked Laz in adult Drosophila and whether it rescues both known and novel phenotypes of NLaz null mutants. Local effects of GPI-linked Laz inside and outside the nervous system promote survival upon different stress forms, and extend lifespan and healthspan of the flies in a cell-type dependent manner. Outside the nervous system, expression in fat body cells but not in hemocytes results in protection. Within the nervous system, glial cell expression is more effective than neuronal expression. Laz actions are sexually dimorphic in some expression domains. Fat storage promotion and not modifications in hydrocarbon profiles or quantities explain the starvation-desiccation resistance caused by Laz overexpression. This effect is exerted when Laz is expressed ubiquitously or in dopaminergic cells, but not in hemocytes. Grasshopper Laz functionally restores the loss of NLaz, rescuing stress-sensitivity as well as premature accumulation of aging-related damage, monitored by advanced glycation end products (AGEs). However Laz does not rescue NLaz courtship behavioral defects. Finally, the presence of two new Lipocalins with predicted GPI-anchors in mosquitoes shows that the functional advantages of GPI-linkage have been commonly exploited by Lipocalins in the arthropodan lineage.

  2. Auxin Resistant1 and PIN-FORMED2 Protect Lateral Root Formation in Arabidopsis under Iron Stress.

    Science.gov (United States)

    Li, Guangjie; Song, Haiyan; Li, Baohai; Kronzucker, Herbert J; Shi, Weiming

    2015-12-01

    A stunted root system is a significant symptom of iron (Fe) toxicity, yet little is known about the effects of excess Fe on lateral root (LR) development. In this work, we show that excess Fe has different effects on LR development in different portions of the Arabidopsis (Arabidopsis thaliana) root system and that inhibitory effects on the LR initiation are only seen in roots newly formed during excess Fe exposure. We show that root tip contact with Fe is both necessary and sufficient for LR inhibition and that the auxin, but not abscisic acid, pathway is engaged centrally in the initial stages of excess Fe exposure. Furthermore, Fe stress significantly reduced PIN-FORMED2 (PIN2)-green fluorescent protein (GFP) expression in root tips, and pin2-1 mutants exhibited significantly fewer LR initiation events under excess Fe than the wild type. Exogenous application of both Fe and glutathione together increased PIN2-GFP expression and the number of LR initiation events compared with Fe treatment alone. The ethylene inhibitor aminoethoxyvinyl-glycine intensified Fe-dependent inhibition of LR formation in the wild type, and this inhibition was significantly reduced in the ethylene overproduction mutant ethylene overproducer1-1. We show that Auxin Resistant1 (AUX1) is a critical component in the mediation of endogenous ethylene effects on LR formation under excess Fe stress. Our findings demonstrate the relationship between excess Fe-dependent PIN2 expression and LR formation and the potential role of AUX1 in ethylene-mediated LR tolerance and suggest that AUX1 and PIN2 protect LR formation in Arabidopsis during the early stages of Fe stress.

  3. Standard classification of resistance to stress-corrosion cracking of heat-treatable Aluminum alloys

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This classification covers alphabetical ratings of the relative resistance to SCC of various mill product forms of the wrought 2XXX, 6XXX, and 7XXX series heat-treated aluminum alloys and the procedure for determining the ratings. 1.2 The ratings do not apply to metal in which the metallurgical structure has been altered by welding, forming, or other fabrication processes. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. Toughness and sulfide stress cracking resistance of 13Cr stainless steel OCTG manufactured by ausforming process

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Yukio; Yamane, Yasuyoshi; Tamaki, Katsuomi [Kawasaki Steel Corp., Handa, Aichi (Japan)

    1995-10-01

    An ausformed and tempered 13Cr martensitic stainless steel newly developed for OCTG gives a better SSC resistance and a higher low temperature toughness than the conventional, quenched and tempered 13Cr steel. The value of Sc obtained by the NACE three point bent beam test for the ausformed and tempered 13Cr steel with the yield strength of 640MPa reaches 10.0 ({times}10ksi) as a result of carbide spheroidization during ausforming, which is compared with 8.0 ({times}10ksi) for the conventional 13Cr steel with the same strength. This treatment also gives a higher low temperature toughness of 150J in Charpy absorbed energy at 0 C owing to fine microstructure, which is compared with 70J for the conventional 13Cr steel.

  5. Soil resistance and resilience to mechanical stresses for three differently managed sandy loam soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Schjønning, Per; Møldrup, Per;

    2012-01-01

    -water potentials than the MCC and CCC soils possibly due to higher biotic binding of soil particles by the greater organic carbon content. The water dispersible claywas negatively correlatedwith the level of clay saturation by organic carbon. The resistance of the soils to compaction, quantified by both......To improve our understanding of how clay-organic carbon dynamics affect soil aggregate strength and physical resilience, we selected three nearby soils (MFC,Mixed Forage Cropping; MCC,Mixed Cash Cropping; CCC, Cereal Cash Cropping)with identical clay content and increasing contents of organic...... carbon (CCCresistance and resilience of the three soils to compaction using air permeability (ka), void ratio (e) and air-filled porosity (ε) as functional indicators and to characterise aggregate stability, strength and friability. Aggregate tensile strength...

  6. [Responses of winter wheat tillers at different positions to low temperature stress at stem elongation stage and their freezing resistance evaluation].

    Science.gov (United States)

    Xu, Hai-cheng; Yin, Yan-ping; Cai, Tie; Ni, Ying-li; Yang, Wei-bing; Peng, Dian-liang; Yang, Dong-qing; Wang, Zhen-lin

    2013-08-01

    Taking two winter wheat cultivars Ji' nan 17 and Shannong 8355 as test materials, this paper measured the superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and the malondialdehyde (MDA) and soluble protein contents in the functional leaves and sheaths of the tillers at different positions at stem elongation stage under low temperature stress, and then, the freezing resistance of the tillers was comprehensively evaluated by the methods of principal component analysis and cluster analysis. The results showed that under low temperature stress, the SOD, POD, and CAT activities in the functional leaves and sheaths of each tiller at stem elongation stage increased, but the MDA and soluble protein contents increased or decreased to some extent. By using principal component analysis and cluster analysis, the tillers of each cultivar were grouped into three kinds of freezing resistance type. For Ji' nan 17, the main stem, tiller I, and tiller II belonged to high freezing resistance type, the tiller III, tiller IV, and tiller I p belonged to medium freezing resistance type, and the tiller II p belonged to low freezing resistance type. For Shannong 8355, the main stem, tiller I, tiller II, and tiller III belonged to high freezing resistance type, the tiller IV and tiller I p belonged to medium freezing resistance type, and the tiller II p belonged to low freezing resistance type. It was concluded that the freezing resistance of the winter wheat tillers at different positions at stem elongation stage differed, with the lower position tillers being more resistant than the higher position tillers.

  7. Green tea extract decreases oxidative stress and improves insulin sensitivity in an animal model of insulin resistance, the fructose- fed rat

    Science.gov (United States)

    Metabolic syndrome is characterized by insulin resistance, dyslipidemia, and increased oxidative stress. Tea polyphenols, as both insulin potentiating factors and antioxidants, might act in preventing the metabolic syndrome. We aimed to determine the effects of green tea extract consumption on oxida...

  8. Age-related and sex-specific differences in proteasome activity in individual Drosophila flies from wild type, longevity-selected and stress resistant strains

    DEFF Research Database (Denmark)

    Hansen, Tina Østergaard; Sarup, Pernille Merete; Loeschcke, Volker;

    2012-01-01

    that in C1 males. However, in longevity-selected LS1 flies the proteasome activity was significantly lower compared to C1 flies, but the sex differences were maintained to some extent. Five other stress resistant lines also had significantly reduced proteasome activity in both sexes. During ageing...

  9. Priming by Hexanoic acid induce activation of mevalonic and linolenic pathways and promotes the emission of plant volatiles.

    Directory of Open Access Journals (Sweden)

    Eugenio eLlorens

    2016-04-01

    Full Text Available Hexanoic acid is a short natural monocarboxylic acid present in some fruits and plants. Previous studies reported that soil drench application of this acid induces effective resistance in tomato plants against Botrytis cinerea and Pseudomonas syringae and in citrus against Alternaria alternata and Xanthomonas citri. In this work, we performed an in deep study of the metabolic changes produced in citrus by the application of hexanoic acid in response to the challenge pathogen Alternaria alternata, focusing on the response of the plant. Moreover, we used 13C labeled hexanoic to analyze its behavior inside the plants. Finally, we studied the volatile emission of the treated plants after the challenge inoculation. Drench application of 13C labeled hexanoic demonstrated that this molecule stays in the roots and is not mobilized to the leaves, suggesting long distance induction of resistance. Moreover, the study of the metabolic profile showed an alteration of more than two hundred molecules differentially induced by the application of the compound and the inoculation with the fungus. Bioinformatics analysis of data showed that most of these altered molecules could be related with the mevalonic and linolenic pathways suggesting the implication of these pathways in the induced resistance mediated by hexanoic acid. Finally, the application of this compound showed an enhancement of the emission of 17 volatile metabolites. Taken together, this study indicates that after the application of hexanoic acid this compound remains in the roots, provoking molecular changes that may trigger the defensive response in the rest of the plant mediated by changes in the mevalonic and linolenic pathways and enhancing the emission of volatile compounds, suggesting for the first time the implication of mevalonic pathway in response to hexanoic application.

  10. Curcumin prevents inflammatory response, oxidative stress and insulin resistance in high fructose fed male Wistar rats: Potential role of serine kinases.

    Science.gov (United States)

    Maithilikarpagaselvi, Nachimuthu; Sridhar, Magadi Gopalakrishna; Swaminathan, Rathinam Palamalai; Zachariah, Bobby

    2016-01-25

    Emerging evidence suggests that high fructose consumption may be a potentially important factor responsible for the rising incidence of insulin resistance and diabetes worldwide. The present study investigated the preventive effect of curcumin on inflammation, oxidative stress and insulin resistance in high fructose fed male Wistar rats at the molecular level. Fructose feeding for 10 weeks caused oxidative stress, inflammation and insulin resistance. Curcumin treatment attenuated the insulin resistance by decreasing IRS-1 serine phosphorylation and increasing IRS-1 tyrosine phosphorylation in the skeletal muscle of high fructose fed rats. It also attenuated hyperinsulinemia, glucose intolerance and HOMA-IR level. Curcumin administration lowered tumor necrosis factor alpha (TNF-α), C reactive protein (CRP) levels and downregulated the protein expression of cyclo-oxygenase 2 (COX-2), protein kinase theta (PKCθ). In addition, inhibitor κB alpha (IκBα) degradation was prevented by curcumin supplementation. Treatment with curcumin inhibited the rise of malondialdehyde (MDA), total oxidant status (TOS) and suppressed the protein expression of extracellular kinase ½ (ERK ½), p38 in the skeletal muscle of fructose fed rats. Further, it enhanced Glutathione Peroxidase (GPx) activity in the muscle of fructose fed rats. At the molecular level, curcumin inhibited the activation of stress sensitive kinases and inflammatory cascades. Our findings conclude that curcumin attenuated glucose intolerance and insulin resistance through its antioxidant and anti-inflammatory effects. Thus, we suggest the use of curcumin as a therapeutic adjuvant in the management of diabetes, obesity and their associated complications.

  11. Curcumin prevents inflammatory response, oxidative stress and insulin resistance in high fructose fed male Wistar rats: Potential role of serine kinases.

    Science.gov (United States)

    Maithilikarpagaselvi, Nachimuthu; Sridhar, Magadi Gopalakrishna; Swaminathan, Rathinam Palamalai; Zachariah, Bobby

    2016-01-25

    Emerging evidence suggests that high fructose consumption may be a potentially important factor responsible for the rising incidence of insulin resistance and diabetes worldwide. The present study investigated the preventive effect of curcumin on inflammation, oxidative stress and insulin resistance in high fructose fed male Wistar rats at the molecular level. Fructose feeding for 10 weeks caused oxidative stress, inflammation and insulin resistance. Curcumin treatment attenuated the insulin resistance by decreasing IRS-1 serine phosphorylation and increasing IRS-1 tyrosine phosphorylation in the skeletal muscle of high fructose fed rats. It also attenuated hyperinsulinemia, glucose intolerance and HOMA-IR level. Curcumin administration lowered tumor necrosis factor alpha (TNF-α), C reactive protein (CRP) levels and downregulated the protein expression of cyclo-oxygenase 2 (COX-2), protein kinase theta (PKCθ). In addition, inhibitor κB alpha (IκBα) degradation was prevented by curcumin supplementation. Treatment with curcumin inhibited the rise of malondialdehyde (MDA), total oxidant status (TOS) and suppressed the protein expression of extracellular kinase ½ (ERK ½), p38 in the skeletal muscle of fructose fed rats. Further, it enhanced Glutathione Peroxidase (GPx) activity in the muscle of fructose fed rats. At the molecular level, curcumin inhibited the activation of stress sensitive kinases and inflammatory cascades. Our findings conclude that curcumin attenuated glucose intolerance and insulin resistance through its antioxidant and anti-inflammatory effects. Thus, we suggest the use of curcumin as a therapeutic adjuvant in the management of diabetes, obesity and their associated complications. PMID:26713546

  12. Using the Model Perennial Grass Brachypodium sylvaticum to Engineer Resistance to Multiple Abiotic Stresses

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Sean; Reguera, Maria; Sade, Nir; Cartwright, Amy; Tobias, Christian; Thilmony, Roger; Blumwald, Eduardo; Vogel, John

    2015-03-20

    We are using the perennial model grass Brachypodium sylvaticum to identify combinations of transgenes that enhance tolerance to multiple, simultaneous abiotic stresses. The most successful transgene combinations will ultimately be used to create improved switchgrass (Panicum virgatum L.) cultivars. To further develop B. sylvaticum as a perennial model grass, and facilitate our planned transcriptional profiling, we are sequencing and annotating the genome. We have generated ~40x genome coverage using PacBio sequencing of the largest possible size selected libraries (18, 22, 25 kb). Our initial assembly using only long-read sequence contained 320 Mb of sequence with an N50 contig length of 315 kb and an N95 contig length of 40 kb. This assembly consists of 2,430 contigs, the largest of which was 1.6 Mb. The estimated genome size based on c-values is 340 Mb indicating that about 20 Mb of presumably repetitive DNA remains yet unassembled. Significantly, this assembly is far superior to an assembly created from paired-end short-read sequence, ~100x genome coverage. The short-read-only assembly contained only 226 Mb of sequence in 19k contigs. To aid the assembly of the scaffolds into chromosome-scale assemblies we produced an F2 mapping population and have genotyped 480 individuals using a genotype by sequence approach. One of the reasons for using B. sylvaticum as a model system is to determine if the transgenes adversely affect perenniality and winter hardiness. Toward this goal, we examined the freezing tolerance of wild type B. sylvaticum lines to determine the optimal conditions for testing the freezing tolerance of the transgenics. A survey of seven accessions noted significant natural variation in freezing tolerance. Seedling or adult Ain-1 plants, the line used for transformation, survived an 8 hour challenge down to -6 oC and 50% survived a challenge down to -9 oC. Thus, we will be able to easily determine if the transgenes compromise freezing tolerance. In the

  13. Trans-translation in Helicobacter pylori: essentiality of ribosome rescue and requirement of protein tagging for stress resistance and competence.

    Directory of Open Access Journals (Sweden)

    Marie Thibonnier

    Full Text Available BACKGROUND: The ubiquitous bacterial trans-translation is one of the most studied quality control mechanisms. Trans-translation requires two specific factors, a small RNA SsrA (tmRNA and a protein co-factor SmpB, to promote the release of ribosomes stalled on defective mRNAs and to add a specific tag sequence to aberrant polypeptides to direct them to degradation pathways. Helicobacter pylori is a pathogen persistently colonizing a hostile niche, the stomach of humans. PRINCIPAL FINDINGS: We investigated the role of trans-translation in this bacterium well fitted to resist stressful conditions and found that both smpB and ssrA were essential genes. Five mutant versions of ssrA were generated in H. pylori in order to investigate the function of trans-translation in this organism. Mutation of the resume codon that allows the switch of template of the ribosome required for its release was essential in vivo, however a mutant in which this codon was followed by stop codons interrupting the tag sequence was viable. Therefore one round of translation is sufficient to promote the rescue of stalled ribosomes. A mutant expressing a truncated SsrA tag was viable in H. pylori, but affected in competence and tolerance to both oxidative and antibiotic stresses. This demonstrates that control of protein degradation through trans-translation is by itself central in the management of stress conditions and of competence and supports a regulatory role of trans-translation-dependent protein tagging. In addition, the expression of smpB and ssrA was found to be induced upon acid exposure of H. pylori. CONCLUSIONS: We conclude to a central role of trans-translation in H. pylori both for ribosome rescue possibly due to more severe stalling and for protein degradation to recover from stress conditions frequently encountered in the gastric environment. Finally, the essential trans-translation machinery of H. pylori is an excellent specific target for the development of

  14. Rosmarinus officinalis L. increases Caenorhabditis elegans stress resistance and longevity in a DAF-16, HSF-1 and SKN-1-dependent manner

    Science.gov (United States)

    Zamberlan, D.C.; Amaral, G.P.; Arantes, L.P.; Machado, M.L.; Mizdal, C.R.; Campos, M.M.A.; Soares, F.A.A.

    2016-01-01

    Improving overall health and quality of life, preventing diseases and increasing life expectancy are key concerns in the field of public health. The search for antioxidants that can inhibit oxidative damage in cells has received a lot of attention. Rosmarinus officinalis L. represents an exceptionally rich source of bioactive compounds with pharmacological properties. In the present study, we explored the effects of the ethanolic extract of R. officinalis (eeRo) on stress resistance and longevity using the non-parasitic nematode Caenorhabditis elegans as a model. We report for the first time that eeRo increased resistance against oxidative and thermal stress and extended C. elegans longevity in an insulin/IGF signaling pathway-dependent manner. These data emphasize the eeRo beneficial effects on C. elegans under stress. PMID:27533765

  15. Rosmarinus officinalis L. increases Caenorhabditis elegans stress resistance and longevity in a DAF-16, HSF-1 and SKN-1-dependent manner.

    Science.gov (United States)

    Zamberlan, D C; Amaral, G P; Arantes, L P; Machado, M L; Mizdal, C R; Campos, M M A; Soares, F A A

    2016-08-01

    Improving overall health and quality of life, preventing diseases and increasing life expectancy are key concerns in the field of public health. The search for antioxidants that can inhibit oxidative damage in cells has received a lot of attention. Rosmarinus officinalis L. represents an exceptionally rich source of bioactive compounds with pharmacological properties. In the present study, we explored the effects of the ethanolic extract of R. officinalis (eeRo) on stress resistance and longevity using the non-parasitic nematode Caenorhabditis elegans as a model. We report for the first time that eeRo increased resistance against oxidative and thermal stress and extended C. elegans longevity in an insulin/IGF signaling pathway-dependent manner. These data emphasize the eeRo beneficial effects on C. elegans under stress.

  16. Rosmarinus officinalis L. increases Caenorhabditis elegans stress resistance and longevity in a DAF-16, HSF-1 and SKN-1-dependent manner.

    Science.gov (United States)

    Zamberlan, D C; Amaral, G P; Arantes, L P; Machado, M L; Mizdal, C R; Campos, M M A; Soares, F A A

    2016-01-01

    Improving overall health and quality of life, preventing diseases and increasing life expectancy are key concerns in the field of public health. The search for antioxidants that can inhibit oxidative damage in cells has received a lot of attention. Rosmarinus officinalis L. represents an exceptionally rich source of bioactive compounds with pharmacological properties. In the present study, we explored the effects of the ethanolic extract of R. officinalis (eeRo) on stress resistance and longevity using the non-parasitic nematode Caenorhabditis elegans as a model. We report for the first time that eeRo increased resistance against oxidative and thermal stress and extended C. elegans longevity in an insulin/IGF signaling pathway-dependent manner. These data emphasize the eeRo beneficial effects on C. elegans under stress. PMID:27533765

  17. Detection of Genes that Determine Maize Grain Quality Characteristics and Resistance to Stress Factors

    Directory of Open Access Journals (Sweden)

    Markovskyi, O.V.

    2014-01-01

    Full Text Available 200 experimental maize samples (Maize Company were examined for the presence of genes that determine the quality characteristics of grain (wx and fl-2 genes, herbicide (bar (pat, epsps genes and insect (cry-genes resistance. The total DNA was extracted from maize living plant tissue. Primers to detect wx, fl-2, bar (pat, mepsps, CP4 epsps, cry1A(b, cry1F, cry1A.105, mcry3A, cry2Ab2, cry3Bb1, cry34Ab1, cry35Ab1 genes were designed and selected. Multiplex and Touchdown PCR were worked out. PCR amplification of certain sequences was carried out. No transgenes (bar (pat, mepsps, CP4 epsps, cry1A(b, cry1F, cry1A.105, mcry3A, cry2Ab2, cry3Bb1, cry34Ab1, cry35Ab1 were found among 200 analyzed experimental maize samples. At the same time, fl-2 gene was found in 41 samples, wx gene was found in 192 analyzed samples.

  18. Positive selection of Caenorhabditis elegans mutants with increased stress resistance and longevity.

    Science.gov (United States)

    Muñoz, Manuel J; Riddle, Donald L

    2003-01-01

    We developed selective conditions for long-lived mutants of the nematode Caenorhabditis elegans by subjecting the first larval stage (L1) to thermal stress at 30 degrees for 7 days. The surviving larvae developed to fertile adults after the temperature was shifted to 15 degrees. A total of one million F(2) progeny and a half million F(3) progeny of ethyl-methanesulfonate-mutagenized animals were treated in three separate experiments. Among the 81 putative mutants that recovered and matured to the reproductive adult, 63 retested as thermotolerant and 49 (80%) exhibited a >15% increase in mean life span. All the known classes of dauer formation (Daf) mutant that affect longevity were found, including six new alleles of daf-2, and a unique temperature-sensitive, dauer-constitutive allele of age-1. Alleles of dyf-2 and unc-13 were isolated, and mutants of unc-18, a gene that interacts with unc-13, were also found to be long lived. Thirteen additional mutations define at least four new genes. PMID:12586705

  19. Air-adapted Methanosarcina acetivorans shows high methane production and develops resistance against oxygen stress.

    Directory of Open Access Journals (Sweden)

    Ricardo Jasso-Chávez

    Full Text Available Methanosarcina acetivorans, considered a strict anaerobic archaeon, was cultured in the presence of 0.4-1% O2 (atmospheric for at least 6 months to generate air-adapted cells; further, the biochemical mechanisms developed to deal with O2 were characterized. Methane production and protein content, as indicators of cell growth, did not change in air-adapted cells respect to cells cultured under anoxia (control cells. In contrast, growth and methane production significantly decreased in control cells exposed for the first time to O2. Production of reactive oxygen species was 50 times lower in air-adapted cells versus control cells, suggesting enhanced anti-oxidant mechanisms that attenuated the O2 toxicity. In this regard, (i the transcripts and activities of superoxide dismutase, catalase and peroxidase significantly increased; and (ii the thiol-molecules (cysteine + coenzyme M-SH + sulfide and polyphosphate contents were respectively 2 and 5 times higher in air-adapted cells versus anaerobic-control cells. Long-term cultures (18 days of air-adapted cells exposed to 2% O2 exhibited the ability to form biofilms. These data indicate that M. acetivorans develops multiple mechanisms to contend with O2 and the associated oxidative stress, as also suggested by genome analyses for some methanogens.

  20. Therapeutic effects of tender coconut water on oxidative stress in fructose fed insulin resistant hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    D Bhagya; L Prema; T Rajamohan

    2012-01-01

    ABSTRACT Objective:To investigate whether tender coconut water(TCW)mitigates oxidative stress in fructose fed hypertensive rats.Methods: Male Sprague Dawley rats were fed with fructose rich diet and treated withTCW (4 mL/100 g of body weight) for3 subsequent weeks. Systolic blood pressure was measured every three days using the indirect tail cuff method. At the end of the experimental period, plasma glucose and insulin, serum triglycerides and free fatty acids, lipid peroxidation markers (MDA, hydroperoxides and conjugated dienes) and the activities of antioxidant enzymes were analyzed in all the groups.Results: Treatment withTCW significantly lowered the systolic blood pressure and reduced serum triglycerides and free fatty acids. Plasma glucose and insulin levels and lipid peroxidation markers such asMDA, hydroperoxides and conjugated dienes were significantly reduced in fructose fed rats treated withTCW. Activities of antioxidant enzymes are up regulated significantly inTCW treated rats. Histopathological analysis of liver showed thatTCW treatment reduced the lipid accumulation and inflammatory infiltration without any significant hepatocellular damage.Conclusions: The overall results suggest that, TCW treatment could prevent and reverse high blood pressure induced by high fructose diet probably by inhibition of lipid peroxidation, upregulation of antioxidant status and improved insulin sensitivity.

  1. Role of Renin-Angiotensin System and Oxidative Stress on Vascular Inflammation in Insulin Resistence Model

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    N. F. Renna

    2013-01-01

    Full Text Available (1 This study aims to demonstrate the causal involvement of renin angiotensin system (RAS and oxidative stress (OS on vascular inflammation in an experimental model of metabolic syndrome (MS achieved by fructose administration to spontaneously hypertensive rats (FFHR during 12 weeks. (2 Chronic treatment with candesartan (C (10 mg/kg per day for the last 6 weeks or 4OH-Tempol (T (10−3 mmol/L in drinking water for the last 6 weeks reversed the increment in metabolic variables and systolic blood pressure. In addition, chronic C treatment reverted cardiovascular remodeling but not T. (3 Furthermore, chronic treatment with C was able to completely reverse the expression of NF-κB and VCAM-1, but T only reduced the expression. C reduced the expression of proatherogenic cytokines as CINC2, CINC3, VEGF, Leptin, TNF-alpha, and MCP-1 and also significantly reduced MIP-3, beta-NGF, and INF-gamma in vascular tissue in this experimental model. T was not able to substantially modify the expression of these cytokines. (4 The data suggest the involvement of RAS in the expression of inflammatory proteins at different vascular levels, allowing the creation of a microenvironment suitable for the creation, perpetuation, growth, and destabilization of vascular injury.

  2. An R2R3 MYB transcription factor in wheat, TaPIMP1, mediates host resistance to Bipolaris sorokiniana and drought stresses through regulation of defense- and stress-related genes.

    Science.gov (United States)

    Zhang, Zengyan; Liu, Xin; Wang, Xindong; Zhou, Miaoping; Zhou, Xianyao; Ye, Xingguo; Wei, Xuening

    2012-12-01

    In this study, we report new insights into the function of a wheat (Triticum aestivum) MYB gene TaPIMP1 through overexpression and underexpression, and its underlying mechanism in wheat. Electrophoretic mobility shift and yeast-one-hybrid assays indicated that TaPIMP1 can bind to five MYB-binding sites including ACI, and activate the expression of the genes with the cis-element, confirming that TaPIMP1 is an MYB transcription activator. TaPIMP1-overexpressing transgenic wheat exhibited significantly enhanced resistance to the fungal pathogen Bipolaris sorokiniana and drought stresses, whereas TaPIMP1-underexpressing transgenic wheat showed more susceptibility to the stresses compared with untransformed wheat, revealing that TaPIMP1 positively modulates host-defense responses to B. sorokiniana and drought stresses. Microarray analysis showed that a subset of defense- and stress-related genes were up-regulated by TaPIMP1. These genes, including TaPIMP1, RD22, TLP4 and PR1a, were regulated by ABA and salicylic acid (SA). TaPIMP1-underexpressing transgenic wheat showed compromised induction of these stress-responsive genes following ABA and SA treatments. In summary, TaPIMP1, as a positive molecular linker, mediates resistance to B. sorokiniana and drought stresses by regulation of stress-related genes in ABA- and SA-signaling pathways in wheat. Furthermore, TaPIMP1 may provide a transgenic tool for engineering multiple-resistance wheat in breeding programs.

  3. The role of MAPK signalling pathways in acetic acid-induced cell death of Saccharomyces cerevisiae

    OpenAIRE

    Azevedo, Flávio Humberto Torres Dias Feio de

    2011-01-01

    Dissertação de mestrado em Genética Molecular Mitogenic Activated Protein Kinase (MAPK) cascades are important signalling pathways that allow yeast cells to swiftly adapt to changing environmental conditions. Previous studies suggested that the High Osmolarity Glycerol (HOG) MAPK pathway and ceramide production are involved in acetic-acid induced apoptosis in yeast. Evidence that changes in the levels of endogenous ceramides can affect yeast cell fate has also been put forth...

  4. Mefenamic acid-induced neutropenia and renal failure in elderly females with hypothyroidism.

    OpenAIRE

    Handa, S I; FREESTONE, S.

    1990-01-01

    We report mefenamic acid-induced non-oliguric renal failure and severe neutropenia occurring simultaneously in two elderly females. The neutropenia was due to maturation arrest of the myeloid series in one patient. Both patients were also hypothyroid, but it is not clear whether this was a predisposing factor to the development of these adverse reactions. However, it would seem prudent not to use mefenamic acid in hypothyroid patients until the hypothyroidism has been corrected.

  5. Nutritional Supplement of Hatchery Eggshell Membrane Improves Poultry Performance and Provides Resistance against Endotoxin Stress

    Science.gov (United States)

    Makkar, S. K.; Rath, N. C.; Packialakshmi, B.; Zhou, Z. Y.; Huff, G. R.; Donoghue, A. M.

    2016-01-01

    Eggshells are significant part of hatchery waste which consist of calcium carbonate crust, membranes, and proteins and peptides of embryonic origins along with other entrapped contaminants including microbes. We hypothesized that using this product as a nutritional additive in poultry diet may confer better immunity to the chickens in the paradigm of mammalian milk that enhances immunity. Therefore, we investigated the effect of hatchery eggshell membranes (HESM) as a short term feed supplement on growth performance and immunity of chickens under bacterial lipopolysaccharide (LPS) challenged condition. Three studies were conducted to find the effect of HESM supplement on post hatch chickens. In the first study, the chickens were fed either a control diet or diets containing 0.5% whey protein or HESM as supplement and evaluated at 5 weeks of age using growth, hematology, clinical chemistry, plasma immunoglobulins, and corticosterone as variables. The second and third studies were done to compare the effects of LPS on control and HESM fed birds at 5 weeks of age following at 4 and 24 h of treatment where the HESM was also sterilized with ethanol to deplete bacterial factors. HESM supplement caused weight gain in 2 experiments and decreased blood corticosterone concentrations. While LPS caused a significant loss in body weight at 24 h following its administration, the HESM supplemented birds showed significantly less body weight loss compared with the control fed birds. The WBC, heterophil/lymphocyte ratio, and the levels of IgG were low in chickens fed diets with HESM supplement compared with control diet group. LPS challenge increased the expression of pro-inflammatory cytokine gene IL-6 but the HESM fed birds showed its effect curtailed, also, which also, favored the up-regulation of anti-inflammatory genes compared with control diet fed chickens. Post hatch supplementation of HESM appears to improve performance, modulate immunity, and increase resistance of

  6. Evolution of Pre- and Post-Copulatory Traits in Male Drosophila melanogaster as a Correlated Response to Selection for Resistance to Cold Stress.

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    Karan Singh

    Full Text Available In Drosophila melanogaster the fitness of males depends on a broad array of reproductive traits classified as pre- and post-copulatory traits. Exposure to cold stress, can reduce sperm number, male mating ability and courtship behavior. Therefore, it is expected that the adaptation to cold stress will involve changes in pre- and post-copulatory traits. Such evolution of reproductive traits in response to cold stress is not well studied.We selected replicate populations of D. melanogaster for resistance to cold shock. Over 37-46 generations of selection, we investigated pre- and post-copulatory traits such as mating latency, copulation duration, mating frequency, male fertility, fitness (progeny production and sperm competitive ability in male flies subjected to cold shock and those not subjected to cold shock.We found that post cold shock, the males from the selected populations had a significantly lower mating latency along with, higher mating frequency, fertility, sperm competitive ability and number of progeny relative to the control populations.While most studies of experimental evolution of cold stress resistance have documented the evolution of survivorship in response to selection, our study clearly shows that adaptation to cold stress involves rapid changes in the pre- and post-copulatory traits. Additionally, improved performances under stressful conditions need not necessarily trade-off with performance under benign conditions.

  7. Biocontrol agents-mediated suppression of oxalic acid induced cell death during Sclerotinia sclerotiorum-pea interaction.

    Science.gov (United States)

    Jain, Akansha; Singh, Akanksha; Singh, Surendra; Sarma, Birinchi Kumar; Singh, Harikesh Bahadur

    2015-05-01

    Oxalic acid (OA) is an important pathogenic factor during early Sclerotinia sclerotiorum-host interaction and might work by reducing hydrogen peroxide production (H2 O2 ). In the present investigation, oxalic acid-induced cell death in pea was studied. Pea plants treated with biocontrol agents (BCAs) viz., Pseudomonas aeruginosa PJHU15, Bacillus subtilis BHHU100, and Trichoderma harzianum TNHU27 either singly and/or in consortium acted on S. sclerotiorum indirectly by enabling plants to inhibit the OA-mediated suppression of oxidative burst via induction of H2 O2 . Our results showed that BCA treated plants upon treatment with culture filtrate of the pathogen, conferred the resistance via. significantly decreasing relative cell death of pea against S. sclerotiorum compared to control plants without BCA treatment but treated with the culture filtrate of the pathogen. The results obtained from the present study indicate that the microbes especially in consortia play significant role in protection against S. sclerotiorum by modulating oxidative burst and partially enhancing tolerance by increasing the H2 O2 generation, which is otherwise suppressed by OA produced by the pathogen.

  8. Heterologous expression of a Tpo1 homolog from Arabidopsis thaliana confers resistance to the herbicide 2,4-D and other chemical stresses in yeast.

    Science.gov (United States)

    Cabrito, Tânia R; Teixeira, Miguel C; Duarte, Alexandra A; Duque, Paula; Sá-Correia, Isabel

    2009-10-01

    The understanding of the molecular mechanisms underlying acquired herbicide resistance is crucial in dealing with the emergence of resistant weeds. Saccharomyces cerevisiae has been used as a model system to gain insights into the mechanisms underlying resistance to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The TPO1 gene, encoding a multidrug resistance (MDR) plasma membrane transporter of the major facilitator superfamily (MFS), was previously found to confer resistance to 2,4-D in yeast and to be transcriptionally activated in response to the herbicide. In this work, we demonstrate that Tpo1p is required to reduce the intracellular concentration of 2,4-D. ScTpo1p homologs encoding putative plasma membrane MFS transporters from the plant model Arabidopsis thaliana were analyzed for a possible role in 2,4-D resistance. At5g13750 was chosen for further analysis, as its transcript levels were found to increase in 2,4-D stressed plants. The functional heterologous expression of this plant open reading frame in yeast was found to confer increased resistance to the herbicide in Deltatpo1 and wild-type cells, through the reduction of the intracellular concentration of 2,4-D. Heterologous expression of At5g13750 in yeast also leads to increased resistance to indole-3-acetic acid (IAA), Al(3+) and Tl(3+). At5g13750 is the first plant putative MFS transporter to be suggested as possibly involved in MDR.

  9. Effect of taurine supplementation on hyperhomocysteinemia and markers of oxidative stress in high fructose diet induced insulin resistance

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    El Mesallamy Hala O

    2010-06-01

    Full Text Available Abstract Background High intake of dietary fructose is accused of being responsible for the development of the insulin resistance (IR syndrome. Concern has arisen because of the realization that fructose, at elevated concentrations, can promote metabolic changes that are potentially deleterious. Among these changes is IR which manifests as a decreased biological response to normal levels of plasma insulin. Methods Oral glucose tolerance tests (OGTT were carried out, homeostasis model assessment of insulin resistance (HOMA was calculated, homocysteine (Hcy, lipid concentrations and markers of oxidative stress were measured in male Wistar rats weighing 170-190 g. The rats were divided into four groups, kept on either control diet or high fructose diet (HFD, and simultaneously supplemented with 300 mg/kg/day taurine via intra-peritoneal (i.p. route for 35 days. Results Fructose-fed rats showed significantly impaired glucose tolerance, impaired insulin sensitivity, hypertriglyceridemia, hypercholesterolemia, hyperhomocysteinemia (HHcy, lower total antioxidant capacity (TAC, lower paraoxonase (PON activity, and higher nitric oxide metabolites (NOx concentration, when compared to rats fed on control diet. Supplementing the fructose-fed rats with taurine has ameliorated the rise in HOMA by 56%, triglycerides (TGs by 22.5%, total cholesterol (T-Chol by 11%, and low density lipoprotein cholesterol (LDL-C by 21.4%. Taurine also abolished any significant difference of TAC, PON activity and NOx concentration among treated and control groups. TAC positively correlated with PON in both rats fed on the HFD and those received taurine in addition to the HFD. Fructose-fed rats showed 34.7% increase in Hcy level. Taurine administration failed to prevent the observed HHcy in the current dosage and duration. Conclusion Our results indicate that HFD could induce IR which could further result in metabolic syndrome (MS, and that taurine has a protective role against

  10. Exposure to high hydrostatic pressure rapidly selects for increased RpoS activity and general stress-resistance in Escherichia coli O157:H7.

    Science.gov (United States)

    Vanlint, Dietrich; Rutten, Nele; Govers, Sander K; Michiels, Chris W; Aertsen, Abram

    2013-04-15

    Exposure to high hydrostatic pressure (HHP) is increasingly being used in food preservation as a non-thermal pasteurization process, and its further implementation necessitates a more thorough understanding of bacterial resistance development and intraspecies variability with regard to inactivation by HHP. In this report, we discovered that exposure to high hydrostatic pressure stress can rapidly select for strongly increased RpoS activity in a hypersensitive Escherichia coli O157:H7 strain (ATCC 43888), leading to a simultaneous increase in HHP and heat resistance. Moreover, the level of RpoS activity correlated well with the original hypersensitivity and the extent of acquired HHP resistance, and extremely HHP-resistant mutants of ATCC 43888 clearly incurred a number of additional RpoS-dependent phenotypes. These findings suggest that implementation of novel processing techniques in the food production chain can readily affect the physiology of food-borne pathogens.

  11. 我国水稻抗逆性研究进展%Progress of Research on Stress Resistance o Rice in China

    Institute of Scientific and Technical Information of China (English)

    黄志谋; 蔡克桐; 沈其文; 周慧梅

    2012-01-01

    从野生稻抗性的挖掘利用、杂交稻的选育及水稻新抗逆性品种、水稻抗逆功能研究、激素与水稻的抗逆性、矿质元素硅和钙对水稻抗逆性增产作用5个方面对我国水稻抗逆性研究进展进行了综术,为提高水稻产量研究提供了参考。%Progress of rice resistance research in China was reviewed in the study based on exploitation of wild rice, breeding of hybrid rice, new resistant rice variety, stress resistance gene, relation between hormone and rice resistance, effects of Si and Ca on yield increase, providing reference for research of rice yield improvement.

  12. Functional analysis of histone deacetylase and its role in stress response, drug resistance and solid-state cultivation in Aspergillus oryzae.

    Science.gov (United States)

    Kawauchi, Moriyuki; Iwashita, Kazuhiro

    2014-08-01

    In the eukaryotic cell, histone deacetylases (HDACs) play key roles in the regulation of fundamental cellular process such as development regulation, stress response, secondary metabolism and genome integrity. Here, we provide a comprehensive phenotypic analysis using HDAC disruptants in Aspergillus oryzae. Our study revealed that four HDACs, hdaA/Aohda1, hdaB/Aorpd3, hdaD/Aohos2 and hst4/AohstD were involved in stress response, cell wall synthesis and chromatin integrity in A. oryzae. Osmotic stress sensitivity of HDAC disruptants differed between plate cultures and liquid cultures, suggesting that HDACs adapt to the difference environmental conditions. Using a common A. oryzae fermentation medium, rice-koji, we also characterized HDACs related to growth and enzyme production to investigate which HDACs will be required for adaptation to environmental conditions and stress resistances. Because HDACs are widely conserved, our study has broad applications and may inform work with filamentous fungi and other eukaryote. PMID:24613105

  13. Resistência ao estresse e crescimento de larvas de peixes neotropicais alimentadas com diferentes dietas Stress resistance and growth of larvae of neotropical fish feed with different diets

    Directory of Open Access Journals (Sweden)

    Ronald Kennedy Luz

    2007-01-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da alimentação na resistência ao estresse e no crescimento de larvas das espécies de peixes neotropicais: Astronotus ocellatus (Oscar, Piaractus mesopotamicus (pacu e Pseudoplatystoma coruscans (pintado. As larvas receberam diferentes tipos de alimentos (Artemia sp., larvas de Colossoma macropomum e dieta artificial Fry Feed Kyowa. Foram realizados testes de exposição ao ar e a taxa de sobrevivência, determinada 24 horas depois. A fim de avaliar o crescimento, medidas de peso foram realizadas em larvas dos diferentes tratamentos. Larvas de A. ocellatus alimentadas com náuplios de Artemia sp. apresentaram tendência de maior peso e resistência ao estresse, quando comparadas com o uso de dieta artificial. Larvas de P. mesopotamicus apresentaram melhores valores de peso e taxas de resistência ao estresse, quando alimentadas com Artemia sp. ou alimentação mista (Artemia sp. + dieta artificial. Em P. coruscans, o uso de larvas forrageiras resultou em indivíduos mais resistentes aos testes de exposição ao ar do que os que receberam apenas Artemia sp. Valores de peso, nos dois manejos alimentares, foram semelhantes entre si. O alimento vivo desempenha importante atuação no crescimento em peso e na melhora da resistência ao estresse das espécies estudadas.The objective of this work was to evaluate the effect of feeding on stress resistance and growth in larvae of neotropical fish of the species: Astronotus ocellatus, Piaractus mesopotamicus, and Pseudoplatystoma coruscans. Larvae received different types of food (Artemia sp., Colossoma macropomum larvae and artificial microdiet Fry Feed Kyowa. Resistance tests to air exposure were applied, and larvae survival was determined after 24 hours. To evaluate the growth, weight measures were performed during the different treatments. A. ocellatus larvae fed on Artemia sp. nauplii tended to better resistant and weight than others that received

  14. Violacein induces death of resistant leukaemia cells via kinome reprogramming, endoplasmic reticulum stress and Golgi apparatus collapse.

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    Karla C S Queiroz

    Full Text Available It is now generally recognised that different modes of programmed cell death (PCD are intimately linked to the cancerous process. However, the mechanism of PCD involved in cancer chemoprevention is much less clear and may be different between types of chemopreventive agents and tumour cell types involved. Therefore, from a pharmacological view, it is crucial during the earlier steps of drug development to define the cellular specificity of the candidate as well as its capacity to bypass dysfunctional tumoral signalling pathways providing insensitivity to death stimuli. Studying the cytotoxic effects of violacein, an antibiotic dihydro-indolone synthesised by an Amazon river Chromobacterium, we observed that death induced in CD34(+/c-Kit(+/P-glycoprotein(+/MRP1(+ TF1 leukaemia progenitor cells is not mediated by apoptosis and/or autophagy, since biomarkers of both types of cell death were not significantly affected by this compound. To clarify the working mechanism of violacein, we performed kinome profiling using peptide arrays to yield comprehensive descriptions of cellular kinase activities. Pro-death activity of violacein is actually carried out by inhibition of calpain and DAPK1 and activation of PKA, AKT and PDK, followed by structural changes caused by endoplasmic reticulum stress and Golgi apparatus collapse, leading to cellular demise. Our results demonstrate that violacein induces kinome reprogramming, overcoming death signaling dysfunctions of intrinsically resistant human leukaemia cells.

  15. Persistent overexpression of phosphoglycerate mutase, a glycolytic enzyme, modifies energy metabolism and reduces stress resistance of heart in mice.

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    Junji Okuda

    Full Text Available BACKGROUND: Heart failure is associated with changes in cardiac energy metabolism. Glucose metabolism in particular is thought to be important in the pathogenesis of heart failure. We examined the effects of persistent overexpression of phosphoglycerate mutase 2 (Pgam2, a glycolytic enzyme, on cardiac energy metabolism and function. METHODS AND RESULTS: Transgenic mice constitutively overexpressing Pgam2 in a heart-specific manner were generated, and cardiac energy metabolism and function were analyzed. Cardiac function at rest was normal. The uptake of analogs of glucose or fatty acids and the phosphocreatine/βATP ratio at rest were normal. A comprehensive metabolomic analysis revealed an increase in the levels of a few metabolites immediately upstream and downstream of Pgam2 in the glycolytic pathway, whereas the levels of metabolites in the initial few steps of glycolysis and lactate remained unchanged. The levels of metabolites in the tricarboxylic acid (TCA cycle were altered. The capacity for respiration by isolated mitochondria in vitro was decreased, and that for the generation of reactive oxygen species (ROS in vitro was increased. Impaired cardiac function was observed in response to dobutamine. Mice developed systolic dysfunction upon pressure overload. CONCLUSIONS: Constitutive overexpression of Pgam2 modified energy metabolism and reduced stress resistance of heart in mice.

  16. Involvement of alternative oxidase in the regulation of growth, development, and resistance to oxidative stress of Sclerotinia sclerotiorum.

    Science.gov (United States)

    Xu, Ting; Yao, Fei; Liang, Wu-Sheng; Li, Yong-Hong; Li, Dian-Rong; Wang, Hao; Wang, Zheng-Yi

    2012-08-01

    Sclerotinia sclerotiorum is a cosmopolitan, filamentous, fungal pathogen that can cause serious disease in many kinds of crops. Alternative oxidase is the terminal oxidase of the alternative mitochondrial respiratory pathway in fungi and higher plants. We report the presence of this alternative pathway respiration and demonstrate its expression in two isolates of S. sclerotiorum under unstressed, normal culture conditions. Application of salicylhydroxamic acid, a specific inhibitor of alternative oxidase, severely inhibited the mycelial growth of S. sclerotiorum both on potato dextrose agar plates and in liquid culture media. Inhibition of alternative oxidase could influence the growth pattern of S. sclerotiorum, as salicylhydroxamic acid treatment induced obvious aerial mycelia growing on potato dextrose agar plates. Under the treatment with salicylhydroxamic acid, S. sclerotiorum formed sclerotia much more slowly than the control. Treatment with hydrogen peroxide in millimolar concentrations greatly decreased the growth rate of mycelia and delayed the formation of sclerotia in both tested S. sclerotiorum isolates. As well, this treatment obviously increased their alternative pathway respiration and the levels of both mRNA and protein of the alternative oxidase. These results indicate that alternative oxidase is involved in the regulation of growth, development, and resistance to oxidative stress of S. sclerotiorum. PMID:22923107

  17. UV Differentially Induces Oxidative Stress, DNA Damage and Apoptosis in BCR-ABL1-Positive Cells Sensitive and Resistant to Imatinib

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    Ewelina Synowiec

    2015-08-01

    Full Text Available Chronic myeloid leukemia (CML cells express the active BCR-ABL1 protein, which has been targeted by imatinib in CML therapy, but resistance to this drug is an emerging problem. BCR-ABL1 induces endogenous oxidative stress promoting genomic instability and imatinib resistance. In the present work, we investigated the extent of oxidative stress, DNA damage, apoptosis and expression of apoptosis-related genes in BCR-ABL1 cells sensitive and resistant to imatinib. The resistance resulted either from the Y253H mutation in the BCR-ABL1 gene or incubation in increasing concentrations of imatinib (AR. UV irradiation at a dose rate of 0.12 J/(m2·s induced more DNA damage detected by the T4 pyrimidine dimers glycosylase and hOGG1, recognizing oxidative modifications to DNA bases in imatinib-resistant than -sensitive cells. The resistant cells displayed also higher susceptibility to UV-induced apoptosis. These cells had lower native mitochondrial membrane potential than imatinib-sensitive cells, but UV-irradiation reversed that relationship. We observed a significant lowering of the expression of the succinate dehydrogenase (SDHB gene, encoding a component of the complex II of the mitochondrial respiratory chain, which is involved in apoptosis sensing. Although detailed mechanism of imatinib resistance in AR cells in unknown, we detected the presence of the Y253H mutation in a fraction of these cells. In conclusion, imatinib-resistant cells may display a different extent of genome instability than their imatinib-sensitive counterparts, which may follow their different reactions to both endogenous and exogenous DNA-damaging factors, including DNA repair and apoptosis.

  18. EFFECTS OF RESIDUAL STRESS ON CASING COLLAPSE RESISTANCE%残余应力对套管抗挤强度影响的有限元分析

    Institute of Scientific and Technical Information of China (English)

    韩建增; 张先普

    2001-01-01

    在套管的生产过程中会产生残余应力,这种残余应力将大大降低套管的拉伸屈服极限及压缩屈服极限,进而降低套管的抗挤强度。长期以来,这个问题一直没有引起人们的充分重视而加以克服。根据弹性力学理论,建立了套管的力学模型,通过有限元分析和计算,得到了存在残余应力情况下套管的抗挤强度。研究表明,残余应力在很大程度上影响着套管的抗挤强度,因此,为了提高套管的抗挤强度,应尽量降低管体的残余应力。%During the production of casing,it will give birth to residual stress.This kind of residual stress will decrease the tensile yield limit and compressive yield limit of casing greatly.As a result,it will decrease casing collapse resistance.For a long time,the problem has not been regarded and resolved.Based on the elastic theory,the mechanical model of casing has been established.Analyzed and calculated by the Finite Element Method,the casing collapse resistance with the existence of residual stress has been obtained.Research shows that the residual stress effects casing collapse resistance in a great degree.Therefore,in order to increase casing collapse resistance,casing residual stress should be decreased as far as possible.

  19. Skin conductance biofeedback training in adults with drug-resistant temporal lobe epilepsy and stress-triggered seizures: a proof-of-concept study.

    Science.gov (United States)

    Micoulaud-Franchi, Jean-Arthur; Kotwas, Iliana; Lanteaume, Laura; Berthet, Christelle; Bastien, Mireille; Vion-Dury, Jean; McGonigal, Aileen; Bartolomei, Fabrice

    2014-12-01

    The present proof-of-concept study investigated the feasibility of skin conductance biofeedback training in reducing seizures in adults with drug-resistant temporal lobe epilepsy (TLE), whose seizures are triggered by stress. Skin conductance biofeedback aims to increase levels of peripheral sympathetic arousal in order to reduce cortical excitability. This might seem somewhat counterintuitive, since such autonomic arousal may also be associated with increased stress and anxiety. Thus, this sought to verify that patients with TLE and stress-triggered seizures are not worsened in terms of stress, anxiety, and negative emotional response to this nonpharmacological treatment. Eleven patients with drug-resistant TLE with seizures triggered by stress were treated with 12 sessions of biofeedback. Patients did not worsen on cognitive evaluation of attentional biases towards negative emotional stimuli (P>.05) or on psychometric evaluation with state anxiety inventory (P = .059); in addition, a significant improvement was found in the Negative Affect Schedule (P = .014) and in the Beck Depression Inventory (P = .009). Biofeedback training significantly reduced seizure frequency with a mean reduction of -48.61% (SD = 27.79) (P = .005). There was a correlation between the mean change in skin conductance activity over the biofeedback treatment and the reduction of seizure frequency (r(11) = .62, P = .042). Thus, the skin conductance biofeedback used in the present study, which teaches patients to achieve an increased level of peripheral sympathetic arousal, was a well-tolerated nonpharmacological treatment. Further, well-controlled studies are needed to confirm the therapeutic value of this nonpharmacological treatment in reducing seizures in adults with drug-resistant TLE with seizures triggered by stress. PMID:25461224

  20. The Staphylococcus aureus Thiol/Oxidative Stress Global Regulator Spx Controls trfA, a Gene Implicated in Cell Wall Antibiotic Resistance

    Science.gov (United States)

    Jousselin, Ambre; Barras, Christine; Lew, Daniel P.

    2013-01-01

    S. aureus combats cell wall antibiotic stress by altered gene expression mediated by various environmental signal sensors. In this study, we examined the transcriptional regulation of trfA, a gene related to mecA of Bacillus subtilis encoding an adaptor protein implicated in multiple roles, notably, proteolysis and genetic competence. Despite strong sequence similarity to B. subtilis mecA, the function of S. aureus trfA remains largely unexplored; however, its deletion leads to almost complete loss of resistance to oxacillin and glycopeptide antibiotics in glycopeptide-intermediate S. aureus (GISA) derivatives of methicillin-susceptible or methicillin-resistant S. aureus (MRSA) clinical or laboratory isolates. Northern blot analysis and 5′ rapid amplification of cDNA ends (RACE) mapping revealed that trfA was expressed monocistronically by three promoters. Cell wall-active antibiotic exposure led to both increased trfA transcription and enhanced steady-state TrfA levels. trfA promoter regulation was not dependent upon the cell wall stress sentinel VraSR and other sensory stress systems, such as GraRS, WalkRK, Stk1/Stp1, and SigB. Notably, we discovered that the global oxidative-stress regulator Spx controlled trfA transcription. This finding was also confirmed using a strain with enhanced Spx levels resulting from a defect in yjbH, encoding a Spx-interacting protein governing Spx proteolytic degradation. A cohort of clinical GISA strains revealed significant steady-state upregulation of trfA compared to corresponding susceptible parental strains, further supporting a role for trfA in antibiotic resistance. These data provide strong evidence for a link between cell wall antibiotic stress and evoked responses mediated by an oxidative-stress sensor. PMID:23629700

  1. Effect of S-Methyl-L-Cysteine on Oxidative Stress, Inflammation and Insulin Resistance in Male Wistar Rats Fed with High Fructose Diet

    Directory of Open Access Journals (Sweden)

    Sithara Thomas

    2015-01-01

    Full Text Available Background: S-methyl cysteine (SMC is a hydrophilic cysteine-containing compound naturally found in garlic and onion. The purpose of the present study was to investigate the protective effect of SMC on oxidative stress, inflammation and insulin resistance in an experiment of metabolic syndrome. Methods: Male Wistar rats were divided into five groups (6 rats in each group, namely; control, control+S-methyl cysteine (SMC, high fructose diet (HFD, HFD+SMC and HFD+metformin. The 60% fructose used for 8 weeks and SMC in the dose of 100 mg/kg bw/day/rat was used in the study. The fasting glucose, insulin, insulin resistance, and tumor necrosis factor alpha and erythrocyte enzymatic antioxidants were measured. Results: Increased levels of plasma glucose, insulin, malondialdehyde, tumor necrosis factor-alpha, and insulin resistance and decreased levels of glutathione, glutathione peroxidase, and catalase were found in rats on a high fructose diet. Oral administration of SMC (100 mg/kg bw/day/rat for 60 days resulted in significant attenuation of plasma glucose, insulin, tumor necrosis factor–alpha, insulin resistance and improved antioxidant enzyme activities. Conclusion: Oral treatment of SMC is effective in improving insulin resistance while attenuating metabolic syndrome, inflammation, and oxidative stress in male rats fed with fructose rich diet.

  2. Renal cells express different forms of vimentin: the independent expression alteration of these forms is important in cell resistance to osmotic stress and apoptosis.

    Directory of Open Access Journals (Sweden)

    Bettina S Buchmaier

    Full Text Available Osmotic stress has been shown to regulate cytoskeletal protein expression. It is generally known that vimentin is rapidly degraded during apoptosis by multiple caspases, resulting in diverse vimentin fragments. Despite the existence of the known apoptotic vimentin fragments, we demonstrated in our study the existence of different forms of vimentin VIM I, II, III, and IV with different molecular weights in various renal cell lines. Using a proteomics approach followed by western blot analyses and immunofluorescence staining, we proved the apoptosis-independent existence and differential regulation of different vimentin forms under varying conditions of osmolarity in renal cells. Similar impacts of osmotic stress were also observed on the expression of other cytoskeleton intermediate filament proteins; e.g., cytokeratin. Interestingly, 2D western blot analysis revealed that the forms of vimentin are regulated independently of each other under glucose and NaCl osmotic stress. Renal cells, adapted to high NaCl osmotic stress, express a high level of VIM IV (the form with the highest molecular weight, besides the three other forms, and exhibit higher resistance to apoptotic induction with TNF-α or staurosporin compared to the control. In contrast, renal cells that are adapted to high glucose concentration and express only the lower-molecular-weight forms VIM I and II, were more susceptible to apoptosis. Our data proved the existence of different vimentin forms, which play an important role in cell resistance to osmotic stress and are involved in cell protection against apoptosis.

  3. Effect of Cudrania tricuspidata and Kaempferol in Endoplasmic Reticulum Stress-Induced Inflammation and Hepatic Insulin Resistance in HepG2 Cells.

    Science.gov (United States)

    Kim, Ok-Kyung; Jun, Woojin; Lee, Jeongmin

    2016-01-21

    In this study, we quantitated kaempferol in water extract from Cudrania tricuspidata leaves (CTL) and investigated its effects on endoplasmic reticulum (ER) stress-induced inflammation and insulin resistance in HepG2 cells. The concentration of kaempferol in the CTL was 5.07 ± 0.08 mg/g. The HepG2 cells were treated with 300 µg/mL of CTL, 500 µg/mL of CTL, 1.5 µg/mL of kaempferol or 2.5 µg/mL of kaempferol, followed immediately by stimulation with 100 nM of thapsigargin for ER stress induction for 24 h. There was a marked increase in the activation of the ER stress and inflammation response in the thapsigargin-stimulated control group. The CTL treatment interrupted the ER stress response and ER stress-induced inflammation. Kaempferol partially inhibited the ER stress response and inflammation. There was a significant increase in serine phosphorylation of insulin receptor substrate (IRS)-1 and the expression of C/EBPα and gluconeogenic genes in the thapsigargin-stimulated control group compared to the normal control. Both CTL and kaempferol suppressed serine phosphorylation of IRS-1, and the treatments did not interrupt the C/EBPα/gluconeogenic gene pathway. These results suggest that kaempferol might be the active compound of CTL and that it might protect against ER stress-induced inflammation and hyperglycemia.

  4. Putrescine differently influences the effect of salt stress on polyamine metabolism and ethylene synthesis in rice cultivars differing in salt resistance

    OpenAIRE

    Quinet, Muriel; Ndayiragije, Alexis; Lefèvre, Isabelle; Lambillotte, Béatrice; Dupont-Gillain, Christine C.; Lutts, Stanley

    2010-01-01

    Effects of salt stress on polyamine metabolism and ethylene production were examined in two rice (Oryza sativa L.) cultivars [I Kong Pao (IKP), salt sensitive; and Pokkali, salt resistant] grown for 5 d and 12 d in nutrient solution in the presence or absence of putrescine (1 mM) and 0, 50, and 100 mM NaCl. The salt-sensitive (IKP) and salt-resistant (Pokkali) cultivars differ not only in their mean levels of putrescine, but also in the physiological functions assumed by this molecule in stre...

  5. Contribution of the drought tolerance-related Stress-responsive NAC1 transcription factor to resistance of barley to Ramularia leaf spot

    OpenAIRE

    McGrann, Graham R. D.; STEED, ANDREW; BURT, CHRISTOPHER; Goddard, Rachel; LACHAUX, CLEA; Bansal, Anuradha; CORBITT, MARGARET; GORNIAK, KALINA; Nicholson, Paul; James K.M. Brown

    2014-01-01

    NAC proteins are plant transcription factors that are involved in tolerance to abiotic and biotic stresses, as well as in many developmental processes. Stress-responsive NAC1 (SNAC1) transcription factor is involved in drought tolerance in barley and rice, but has not been shown previously to have a role in disease resistance. Transgenic over-expression of HvSNAC1 in barley cv. Golden Promise reduced the severity of Ramularia leaf spot (RLS), caused by the fungus Ramularia collo-cygni, but ha...

  6. Low Temperature-Induced 30 (LTI30) positively regulates drought stress resistance in Arabidopsis: effect on abscisic acid sensitivity and hydrogen peroxide accumulation

    OpenAIRE

    Shi, Haitao; Chen, Yinhua; Qian, Yongqiang; Chan, Zhulong

    2015-01-01

    As a dehydrin belonging to group II late embryogenesis abundant protein (LEA) family, Arabidopsis Low Temperature-Induced 30 (LTI30)/XERO2 has been shown to be involved in plant freezing stress resistance. However, the other roles of AtLTI30 remain unknown. In this study, we found that the expression of AtLTI30 was largely induced by drought stress and abscisic acid (ABA) treatments. Thereafter, AtLTI30 knockout mutants and overexpressing plants were isolated to investigate the possible invol...

  7. Influence of nitrogen on the stress corrosion cracking resistance of austenitic stainless steels in chloride environment; Influence de l'azote sur la resistance a la corrosion sous contrainte d'aciers inoxydables austenitiques en milieu chlorure

    Energy Technology Data Exchange (ETDEWEB)

    Teysseyre, S

    2001-11-01

    The aim of this study is to investigate the influence of nitrogen additions on the Stress Corrosion Cracking (SSC) resistance of austenitic stainless steel in chloride environment. The investigation was carried out in two part: first, an experimental investigation with model industrial steels was carried out and secondly, numerical simulations based on the Corrosion Enhanced Plasticity Model were developed. Both slow strain rate tensile tests and constant load test of the different steels in boiling MgCl{sub 2} (153 deg C) at free potential show that, for a given plastic strain rate, nitrogen addition increases the critical stress for crack initiation without influencing the crack propagation rate. We observed that the creep rate under constant load was affected by the nitrogen content. As a consequence, the SCC behaviour (cracks density and propagation rate) depends on the nitrogen content. We thus confirm that the nitrogen content influences the corrosion - deformation interaction mechanisms via its positive contribution to the flow stress. These experimental results are reproduced semi-quantitatively by means of numerical simulations at the scale of crack. - dislocation interactions. The presence of nitrogen is modelled by an increased lattice friction stress, which in turn affects the dynamics of crack tip shielding by dislocation pile-ups. We conclude that nitrogen addition in austenitic stainless steels increases the SC crack initiation stress in proportion of the increased flow stress, without penalty in terms of SC crack propagation rate. (author)

  8. Clavulanic acid induces penile erection and yawning in male rats: comparison with apomorphine.

    Science.gov (United States)

    Sanna, Fabrizio; Melis, Maria Rosaria; Angioni, Laura; Argiolas, Antonio

    2013-02-01

    The beta-lactamase inhibitor clavulanic acid induced penile erection and yawning in a dose dependent manner when given intraperitoneally (IP, 0.05-5mg/kg), perorally (OS, 0.1-5mg/kg) and intracereboventricularly (ICV, 0.01-5 μg/rat) to male rats. The effect resembles that of the dopamine receptor agonist apomorphine given subcutaneously (SC) (0.02-0.25mg/kg), although the responses of the latter followed a U inverted dose-response curve, disappearing at doses higher than 0.1mg/kg. Clavulanic acid responses were reduced by about 55% by haloperidol, a dopamine D2 receptor antagonist (0.1mg/kg IP), and by d(CH(2))(5)Tyr(Me)(2)-Orn(8)-vasotocin, an oxytocin receptor antagonist (2 μg/rat ICV), both given 15 min before clavulanic acid. A higher reduction of clavulanic acid responses (more than 80%) was also found with morphine, an opioid receptor agonist (5mg/kg IP), and with mianserin, a serotonin 5HT(2c) receptor antagonist (0.2mg/kg SC). In contrast, no reduction was found with naloxone, an opioid receptor antagonist (1mg/kg IP). The ability of haloperidol, d(CH(2))(5)Tyr(Me)(2)-Orn(8)-vasotocin and morphine to reduce clavulanic acid induced penile erection and yawning suggests that clavulanic acid induces these responses, at least in part, by increasing central dopaminergic neurotransmission. Dopamine in turn activates oxytocinergic neurotransmission and centrally released oxytocin induces penile erection and yawning. However, since both penile erection and yawning episodes were reduced not only by the blockade of central dopamine and oxytocin receptors and by the stimulation of opioid receptors, which inhibits oxytocinergic neurotransmission, but also by mianserin, an increase of central serotonin neurotransmission is also likely to participate in these clavulanic acid responses.

  9. Luteolin prevents uric acid-induced pancreatic β-cell dysfunction

    OpenAIRE

    Ding, Ying; Shi, Xuhui; Shuai, Xuanyu; Xu, Yuemei; Liu, Yun; Liang, Xiubin; Wei, Dong; Su, Dongming

    2014-01-01

    Abstract Elevated uric acid causes direct injury to pancreatic β-cells. In this study, we examined the effects of luteolin, an important antioxidant, on uric acid-induced β-cell dysfunction. We first evaluated the effect of luteolin on nitric oxide (NO) formation in uric acid-stimulated Min6 cells using the Griess method. Next, we performed transient transfection and reporter assays to measure transcriptional activity of nuclear factor (NF)-κB. Western blotting assays were also performed to a...

  10. Reduction of sodium deoxycholic acid-induced scratching behaviour by bradykinin B2 receptor antagonists

    OpenAIRE

    Hayashi, Izumi; Majima, Masataka

    1999-01-01

    Subcutaneous injection of sodium deoxycholic acid into the anterior of the back of male ddY mice elicited dose-dependent scratching of the injected site with the forepaws and hindpaws.Up to 100 μg of sodium deoxycholic acid induced no significant increase in vascular permeability at the injection site as assessed by a dye leakage method.Bradykinin (BK) B2 receptor antagonists, FR173657 and Hoe140, significantly decreased the frequency of scratching induced by sodium deoxycholic acid.Treatment...

  11. Selenium-containing polysaccharides from Ziyang green tea ameliorate high-fructose diet induced insulin resistance and hepatic oxidative stress in mice.

    Science.gov (United States)

    Ren, Daoyuan; Hu, Yuanyuan; Luo, Yiyang; Yang, Xingbin

    2015-10-01

    The present study was designed to evaluate the effects of selenium-containing tea polysaccharides (Se-GTP) from a new variety of selenium-enriched Ziyang green tea against high fructose (HF)-induced insulin resistance and hepatic oxidative stress in mice. Healthy male Kunming mice were fed 20% high fructose water and administered 200, 400 and 800 mg per kg bw Se-GTP for 8 weeks. Mice fed HF in drinking water displayed significant insulin resistance, hepatic steatosis and oxidative stress observed by hyperglycemia and hyperinsulinemia, as well as increases in hepatic non-esterified fatty acid (NEFA) and malonaldehyde (MDA). The administration of Se-GTP at 400 and 800 mg per kg bw significantly improved insulin sensitivity, and reduced liver steatosis and oxidative stress damage, and brought back the antioxidants and hepatic lipids towards near-normal values. In the oral glucose tolerance test, the administration of Se-GTP at 400 and 800 mg per kg bw had reduced plasma glucose concentrations after 30 min of glucose loading in HF-fed mice, suggesting that Se-GTP improved glucose intolerance. Histopathological examination indicated that the impaired pancreatic/hepatic tissues were effectively restored in HF-fed mice following the Se-GTP treatment. This is the first report showing that Se-GTP can ameliorate the high fructose-induced insulin resistance and hepatic oxidative injury.

  12. A comparing study of alloy 600 and alloy 690 on resistance to intergranular stress corrosion cracking(IGSCC)

    International Nuclear Information System (INIS)

    In order to compare the effect of senitization on the intergranular stress corrosion cracking(IGSCC) between Alloy 600 and Alloy 690, these alloys have been sensitized for 1 to 100 hours at 700 .deg. C. The degree of sensitization(DOS) has evaluated by the ratio of Ir(the maximum current density at anodic scan) to Ia(the maximum current density at reverse scan) in the modified double loop EPR(electrochemical potentiokinetic reactivation) test in 0.01M H2SO4 + 0.0001M KSCN at 25 .deg. C and at scan rate of 0.5mV/sec. The susceptibility to IGSCC has been measured in 0.01M Na2S4O6 solution using CERT(constant extension rate tester) at strain rate of 1.0 x 10-6S-1. With increasing sensitization time the DOS of Alloy 600 increases to the maximum value at 5 hours and decreases gradually due to the replenishment of Cr to the Cr-depleted grain boundaries. For Alloy 600 samples except those sensitized for less than 1 hour, the DOS measured by the modified EPR test parallel to susceptibility to IGSCC revealed by the ratio of strain to failure (εf, Na2S4O6/εf, Air). It appears that the susceptibility to IGSCC is closely associated with the depth in Cr-depleted concentration profile across grain boundary. For the sensitized Alloy 690 samples exhibited extremely low value of Ir/Ia less than 0.074% and also were immune to IGSCC. The good resistance of Alloy 690 to IGSCC is considered to be attributed to the higher Cr concentration to avoid serious Cr-depletion problems adjacent to grain boundary

  13. Effects of Ala-Gln feeding strategies on growth, metabolism, and crowding stress resistance of juvenile Cyprinus carpio var. Jian.

    Science.gov (United States)

    Chen, Xiu-Mei; Guo, Gui-Liang; Sun, Li; Yang, Qiu-Shi; Wang, Gui-Qin; Qin, Gui-Xin; Zhang, Dong-Ming

    2016-04-01

    The present study was conducted to evaluate the effects of different L-alanyl-l-glutamine (Ala-Gln) feeding strategies on the growth performance, metabolism and crowding stress resistance related parameters in juvenile Jian carp (Cyprinus carpio var. Jian) under crowded condition (80 g/L). Juvenile Jian carp (initial weight 26.1 ± 0.6 g) were distributed into five groups which fed with graded concentrations (0% or 1.0%) of Ala-Gln for eight weeks. Control group (I, 0/0) fed with control diet (0% Ala-Gln) throughout the feeding trial. The other four groups employed different control and experimental diet feeding strategies ranging from two weeks control diet fed and two weeks experimental diet (1% Ala-Gln) fed (II, 0/2) to eight weeks experimental diet fed (V, 4/4). Results revealed that Mean weight gain (MEG) under all different feeding strategies of Ala-Gln were significantly higher than that of the control group (p blood total protein of groups II, III and V were significantly higher than that in groups I and IV (p glucose, cortisol and catecholamine in fish. The mRNA expression of GR1a, GR1b and GR2 were also significantly changed in Ala-Gln supplementation groups compared with control group (p control group (p optimal feeding strategy was alternatively fed with control diet and then experimental diet at an interval of two weeks for juvenile Jian carp under crowded condition. PMID:26945938

  14. Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillside

    Institute of Scientific and Technical Information of China (English)

    陈欣; 杨一松; 唐建军

    2004-01-01

    Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang)orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m2 and separated by 2 m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positiveecological effects on citrus orchard ecosystem stability.

  15. Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillsid

    Institute of Scientific and Technical Information of China (English)

    陈欣; 杨一松; 唐建军

    2004-01-01

    Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability.

  16. Identification of CBF14 and NAC2 Genes in Aegilops tauschii Associated with Resistance to Freezing Stress.

    Science.gov (United States)

    Masoomi-Aladizgeh, Farhad; Aalami, Ali; Esfahani, Masoud; Aghaei, Mohamad Jaafar; Mozaffari, Khadijeh

    2015-06-01

    Low temperature as one of the most important environmental factors limits the productivity of plants across the world. Aegilops, as a wild species of Poaceae, contains low temperature-responsive genes. In this study, we analyzed morphological (wilting, chlorosis, and recovery) and physiological (ion leakage) characteristics to identification of a cold-tolerant genotype. In this experiment, we introduced two transcription factors (TFs) in Aegilops species for the first time. Bioinformatics analysis demonstrated that our nucleotide sequences have high similarity with CBF14 (C-repeat-binding factor) and NAC2 (NAM, ATAF, and CUC) in Triticum aestivum. Based on the physiological and morphological data, one genotype (Aladizgeh) was identified as the most resistant genotype which was selected for further gene expression analysis. The real-time PCR results indicated that the CBF14 gene was not expressed 3 h following cold treatment, but the highest expression was observed after 6, 12, and 24 h of cold treatment; however, a sudden decrease was observed in its expression after 30 h. The NAC2 gene also was not expressed 3 h after cold stress, but the highest expression was at 24 h and similar to the CBF14 gene; its expression suddenly decreased after 30 h. Our results indicated that this genotype can tolerate -4 °C for 3 h, but the CBF14 and NAC2 genes were activated when treated for longer durations. Expression of TFs studied in this experiment had decreased after 30 h, in which cell death seems to be the important reason.

  17. Rifampin Resistance rpoB Alleles or Multicopy Thioredoxin/Thioredoxin Reductase Suppresses the Lethality of Disruption of the Global Stress Regulator spx in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Villanueva, Maite; Jousselin, Ambre; Baek, Kristoffer T;

    2016-01-01

    is a thiol/oxidative stress sensor that interacts with the C-terminal domain of the RNA polymerase RpoA subunit, leading to changes in gene expression that help sustain viability under various conditions. Using genetic and deep-sequencing methods, we show that spx is essential in S. aureus...... thioredoxin reductase) supports strains with the deletion of spx Our results reveal intriguing properties, especially of RNA polymerase, that compensate for the loss of an essential gene that is a key mediator of diverse processes in S. aureus, including redox and thiol homeostasis, antibiotic resistance...... discovered that Spx, an RNA polymerase-interacting stress regulator implicated in many stress responses in S. aureus, including responses to oxidative and cell wall antibiotics, is essential. We describe two mechanisms that suppress the lethality of spx disruption. One mechanism highlights how only certain...

  18. The stress granule protein Vgl1 and poly(A)-binding protein Pab1 are required for doxorubicin resistance in the fission yeast Schizosaccharomyces pombe

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Takahiro [Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, Kowakae 3-4-1, Higashi-Osaka 577-8502 (Japan); Satoh, Ryosuke [Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, Kowakae 3-4-1, Higashi-Osaka 577-8502 (Japan); Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472 (Japan); Umeda, Nanae; Kita, Ayako [Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, Kowakae 3-4-1, Higashi-Osaka 577-8502 (Japan); Sugiura, Reiko, E-mail: sugiurar@phar.kindai.ac.jp [Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, Kowakae 3-4-1, Higashi-Osaka 577-8502 (Japan)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Stress granules (SGs) as a mechanism of doxorubicin tolerance. Black-Right-Pointing-Pointer We characterize the role of stress granules in doxorubicin tolerance. Black-Right-Pointing-Pointer Deletion of components of SGs enhances doxorubicin sensitivity in fission yeast. Black-Right-Pointing-Pointer Doxorubicin promotes SG formation when combined with heat shock. Black-Right-Pointing-Pointer Doxorubicin regulates stress granule assembly independent of eIF2{alpha} phosphorylation. -- Abstract: Doxorubicin is an anthracycline antibiotic widely used for chemotherapy. Although doxorubicin is effective in the treatment of several cancers, including solid tumors and leukemias, the basis of its mechanism of action is not completely understood. Here, we describe the effects of doxorubicin and its relationship with stress granules formation in the fission yeast, Schizosaccharomyces pombe. We show that disruption of genes encoding the components of stress granules, including vgl1{sup +}, which encodes a multi-KH type RNA-binding protein, and pab1{sup +}, which encodes a poly(A)-binding protein, resulted in greater sensitivity to doxorubicin than seen in wild-type cells. Disruption of the vgl1{sup +} and pab1{sup +} genes did not confer sensitivity to other anti-cancer drugs such as cisplatin, 5-fluorouracil, and paclitaxel. We also showed that doxorubicin treatment promoted stress granule formation when combined with heat shock. Notably, doxorubicin treatment did not induce hyperphosphorylation of eIF2{alpha}, suggesting that doxorubicin is involved in stress granule assembly independent of eIF2{alpha} phosphorylation. Our results demonstrate the usefulness of fission yeast for elucidating the molecular targets of doxorubicin toxicity and suggest a novel drug-resistance mechanism involving stress granule assembly.

  19. Resistance to the development of stress-induced behavioral despair in the forced swim test associated with elevated hippocampal Bcl-xl expression.

    Science.gov (United States)

    Shishkina, Galina T; Kalinina, Tatyana S; Berezova, Inna V; Bulygina, Veta V; Dygalo, Nikolay N

    2010-12-01

    Stress may predispose individuals toward depression through down-regulation of neurogenesis and increase in apoptosis in the brain. However, many subjects show high resistance to stress in relation to psychopathology. In the present study, we assessed the possibility that individual-specific patterns of gene expression associated with cell survival and proliferation may be among the molecular factors underlying stress resilience. Brain-derived neurotrophic factor (BDNF), anti-apoptotic B cell lymphoma like X (Bcl-xl) and pro-apoptotic bcl2-associated X protein (Bax) expression were determined in the hippocampus and frontal cortex of rats naturally differed in despair-like behavior in the forced swim test. In the hippocampus, BDNF messenger RNA (mRNA) level was significantly down-regulated 2h after the forced swim test exposure, and at this time point, Bcl-xl mRNA and protein levels were significantly higher in stressed than in untested animals. The ratios of hippocampal Bcl-xl to Bax mRNA negatively correlated with the total time spent immobile in the test. When animals were divided in two groups according to immobility responses in two consecutive swim sessions and designated as stress resilient if their immobility time did not increase in the second session as it did in stress sensitive rats, it was found that resilient rats had significantly higher Bcl-xl/Bax ratios in the hippocampus than stress sensitive animals. The data suggest that naturally occurring variations in the Bcl-xl/Bax ratio in the hippocampus may contribute to individual differences in vulnerability to stress-induced depression-like behaviors.

  20. STRUCTURAL REMODELING OF PROTEOGLYCANS UPON RETINOIC ACID-INDUCED DIFFERENTIATION OF NCCIT CELLS*

    Science.gov (United States)

    Gasimli, Leyla; Stansfield, Hope E.; Nairn, Alison V.; Liu, Haiying; Paluh, Janet L.; Yang, Bo; Dordick, Jonathan S.; Moremen, Kelley W.; Linhardt, Robert J.

    2012-01-01

    Pluripotent and multipotent cells become increasingly lineage restricted through differentiation. Alterations to the cellular proteoglycan composition and structure should accompany these changes to influence cell proliferation, delineation of tissues and acquisition of cell migration capabilities. Retinoic acid plays an important role in pre-patterning of the early embryo. Retinoic acid can be used in vitro to induce differentiation, causing pluripotent and multipotent cells to become increasingly lineage restricted. We examined retinoic acid-induced changes in the cellular proteoglycan composition of the well-characterized teratocarcinoma line NCCIT. Our analysis revealed changes in the abundance of transcripts for genes encoding core proteins, enzymes that are responsible for early and late linkage region biosynthesis, as well as enzymes for GAG chain extension and modification. Transcript levels for genes encoding core proteins used as backbones for polysaccharide synthesis revealed highly significant increases in expression of lumican and decorin, 1500-fold and 2800-fold, respectively. Similarly, glypican 3, glypican 5, versican and glypican 6 showed increases between 5 and 70-fold. Significant decreases in biglycan, serglycin, glypican 4, aggrecan, neurocan, CD74 and glypican 1 were observed. Disaccharide analysis of the glycans in heparin/heparan sulfate and chondroitin/dermatan sulfate revealed retinoic acid-induced changes restricted to chondroitin/dermatan sulfate glycans. Our study provides the first detailed analysis of changes in the glycosaminoglycan profile of human pluripotent cells upon treatment with the retinoic acid morphogen. PMID:23053635

  1. Structural remodeling of proteoglycans upon retinoic acid-induced differentiation of NCCIT cells.

    Science.gov (United States)

    Gasimli, Leyla; Stansfield, Hope E; Nairn, Alison V; Liu, Haiying; Paluh, Janet L; Yang, Bo; Dordick, Jonathan S; Moremen, Kelley W; Linhardt, Robert J

    2013-07-01

    Pluripotent and multipotent cells become increasingly lineage restricted through differentiation. Alterations to the cellular proteoglycan composition and structure should accompany these changes to influence cell proliferation, delineation of tissues and acquisition of cell migration capabilities. Retinoic acid plays an important role in pre-patterning of the early embryo. Retinoic acid can be used in vitro to induce differentiation, causing pluripotent and multipotent cells to become increasingly lineage restricted. We examined retinoic acid-induced changes in the cellular proteoglycan composition of the well-characterized teratocarcinoma line NCCIT. Our analysis revealed changes in the abundance of transcripts for genes encoding core proteins, enzymes that are responsible for early and late linkage region biosynthesis, as well as enzymes for GAG chain extension and modification. Transcript levels for genes encoding core proteins used as backbones for polysaccharide synthesis revealed highly significant increases in expression of lumican and decorin, 1,500-fold and 2,800-fold, respectively. Similarly, glypican 3, glypican 5, versican and glypican 6 showed increases between 5 and 70-fold. Significant decreases in biglycan, serglycin, glypican 4, aggrecan, neurocan, CD74 and glypican 1 were observed. Disaccharide analysis of the glycans in heparin/heparan sulfate and chondroitin/dermatan sulfate revealed retinoic acid-induced changes restricted to chondroitin/dermatan sulfate glycans. Our study provides the first detailed analysis of changes in the glycosaminoglycan profile of human pluripotent cells upon treatment with the retinoic acid morphogen. PMID:23053635

  2. Obestatin Accelerates the Healing of Acetic Acid-Induced Colitis in Rats

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    Aleksandra Matuszyk

    2016-01-01

    Full Text Available Obestatin, a 23-amino acid peptide derived from the proghrelin, has been shown to exhibit some protective and therapeutic effects in the gut. The aim of present study was to determine the effect of obestatin administration on the course of acetic acid-induced colitis in rats. Materials and Methods. Studies have been performed on male Wistar rats. Colitis was induced by a rectal enema with 3.5% acetic acid solution. Obestatin was administered intraperitoneally twice a day at a dose of 8 nmol/kg, starting 24 h after the induction of colitis. Seven or 14 days after the induction of colitis, the healing rate of the colon was evaluated. Results. Treatment with obestatin after induction of colitis accelerated the healing of colonic wall damage and this effect was associated with a decrease in the colitis-evoked increase in mucosal activity of myeloperoxidase and content of interleukin-1β. Moreover, obestatin administration significantly reversed the colitis-evoked decrease in mucosal blood flow and DNA synthesis. Conclusion. Administration of exogenous obestatin exhibits therapeutic effects in the course of acetic acid-induced colitis and this effect is related, at least in part, to the obestatin-evoked anti-inflammatory effect, a