Mechanisms of neuroimmune gene induction in alcoholism.

Science.gov (United States)

Crews, Fulton T; Vetreno, Ryan P

2016-05-01

Alcoholism is a primary, chronic relapsing disease of brain reward, motivation, memory, and related circuitry. It is characterized by an individual's continued drinking despite negative consequences related to alcohol use, which is exemplified by alcohol use leading to clinically significant impairment or distress. Chronic alcohol consumption increases the expression of innate immune signaling molecules (ISMs) in the brain that alter cognitive processes and promote alcohol drinking. Unraveling the mechanisms of alcohol-induced neuroimmune gene induction is complicated by positive loops of multiple cytokines and other signaling molecules that converge on nuclear factor kappa-light-chain-enhancer of activated B cells and activator protein-1 leading to induction of additional neuroimmune signaling molecules that amplify and expand the expression of ISMs. Studies from our laboratory employing reverse transcription polymerase chain reaction (RT-PCR) to assess mRNA, immunohistochemistry and Western blot analysis to assess protein expression, and others suggest that ethanol increases brain neuroimmune gene and protein expression through two distinct mechanisms involving (1) systemic induction of innate immune molecules that are transported from blood to the brain and (2) the direct release of high-mobility group box 1 (HMGB1) from neurons in the brain. Released HMGB1 signals through multiple receptors, particularly Toll-like receptor (TLR) 4, that potentiate cytokine receptor responses leading to a hyperexcitable state that disrupts neuronal networks and increases excitotoxic neuronal death. Innate immune gene activation in brain is persistent, consistent with the chronic relapsing disease that is alcoholism. Expression of HMGB1, TLRs, and other ISMs is increased several-fold in the human orbital frontal cortex, and expression of these molecules is highly correlated with each other as well as lifetime alcohol consumption and age of drinking onset. The persistent and

DMPD: LPS induction of gene expression in human monocytes. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 11257452 LPS induction of gene expression in human monocytes. Guha M, Mackman N. Ce...ll Signal. 2001 Feb;13(2):85-94. (.png) (.svg) (.html) (.csml) Show LPS induction of gene expression in human... monocytes. PubmedID 11257452 Title LPS induction of gene expression in human monocytes. Authors Guha M, Ma

The Arabidopsis histone chaperone FACT is required for stress-induced expression of anthocyanin biosynthetic genes.

Science.gov (United States)

Pfab, Alexander; Breindl, Matthias; Grasser, Klaus D

2018-03-01

The histone chaperone FACT is involved in the expression of genes encoding anthocyanin biosynthetic enzymes also upon induction by moderate high-light and therefore contributes to the stress-induced plant pigmentation. The histone chaperone FACT consists of the SSRP1 and SPT16 proteins and associates with transcribing RNAPII (RNAPII) along the transcribed region of genes. FACT can promote transcriptional elongation by destabilising nucleosomes in the path of RNA polymerase II, thereby facilitating efficient transcription of chromatin templates. Transcript profiling of Arabidopsis plants depleted in SSRP1 or SPT16 demonstrates that only a small subset of genes is differentially expressed relative to wild type. The majority of these genes is either up- or down-regulated in both the ssrp1 and spt16 plants. Among the down-regulated genes, those encoding enzymes of the biosynthetic pathway of the plant secondary metabolites termed anthocyanins (but not regulators of the pathway) are overrepresented. Upon exposure to moderate high-light stress several of these genes are up-regulated to a lesser extent in ssrp1/spt16 compared to wild type plants, and accordingly the mutant plants accumulate lower amounts of anthocyanin pigments. Moreover, the expression of SSRP1 and SPT16 is induced under these conditions. Therefore, our findings indicate that FACT is a novel factor required for the accumulation of anthocyanins in response to light-induction.

Multiple Two-Component Systems of Streptococcus mutans Regulate Agmatine Deiminase Gene Expression and Stress Tolerance▿

OpenAIRE

Liu, Yaling; Burne, Robert A.

2009-01-01

Induction of the agmatine deiminase system (AgDS) of Streptococcus mutans requires agmatine and is optimal at low pH. We show here that the VicRK, ComDE, and CiaRH two-component systems influence AgDS gene expression in response to acidic and thermal stresses.

Satellite III non-coding RNAs show distinct and stress-specific patterns of induction

International Nuclear Information System (INIS)

Sengupta, Sonali; Parihar, Rashmi; Ganesh, Subramaniam

2009-01-01

The heat shock response in human cells is associated with the transcription of satellite III repeats (SatIII) located in the 9q12 locus. Upon induction, the SatIII transcripts remain associated with the locus and recruit several transcription and splicing factors to form the nuclear stress bodies (nSBs). The nSBs are thought to modulate epigenetic changes during the heat shock response. We demonstrate here that the nSBs are induced by a variety of stressors and show stress-specific patterns of induction. While the transcription factor HSF1 is required for the induction of SatIII locus by the stressors tested, its specific role in the transcriptional process appears to be stress dependent. Our results suggest the existence of multiple transcriptional loci for the SatIII transcripts and that their activation might depend upon the type of stressors. Thus, induction of SatIII transcripts appears to be a generic response to a variety of stress conditions.

The Role of the Exo-Xis Region in Oxidative Stress-Mediated Induction of Shiga Toxin-Converting Prophages

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Katarzyna Licznerska

2016-01-01

Full Text Available Previous studies indicated that these genetic elements could be involved in the regulation of lysogenization and prophage induction processes. The effects were dramatic in Shiga toxin-converting phage Φ24B after treatment with oxidative stress-inducing agent, hydrogen peroxide, while they were less pronounced in bacteriophage λ and in both phages irradiated with UV. The hydrogen peroxide-caused prophage induction was found to be RecA-dependent. Importantly, in hydrogen peroxide-treated E. coli cells lysogenic for either λ or Φ24B, deletion of the exo-xis region resulted in a significant decrease in the levels of expression of the S.O.S. regulon genes. Moreover, under these conditions, a dramatic decrease in the levels of expression of phage genes crucial for lytic development (particularly xis, exo, N, cro, O, Q, and R could be observed in Φ24B-, but not in λ-bearing cells. We conclude that genes located in the exo-xis region are necessary for efficient expression of both host S.O.S regulon in lysogenic bacteria and regulatory genes of Shiga toxin-converting bacteriophage Φ24B.

Nodularin induces tumor necrosis factor-alpha and mitogen-activated protein kinases (MAPK) and leads to induction of endoplasmic reticulum stress

Energy Technology Data Exchange (ETDEWEB)

Meili, Nicole; Christen, Verena [University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich (ETH Zürich), Department of Environmental Systems Science, CH-8092 Zürich (Switzerland)

2016-06-01

Nodularin is produced by the cyanobacterium Nodularia spumigena. It is of concern due to hepatotoxicity in humans and animals. Here we investigated unexplored molecular mechanisms by transcription analysis in human liver cells, focusing on induction of pro-inflammatory cytokines, the tumor necrosis factor α (TNF-α), endoplasmic reticulum (ER) stress and components of the activator protein-1 complex in human hepatoma cells (Huh7) exposed to non-cytotoxic (0.1 and 1 μM) and toxic concentrations (5 μM) for 24, 48, and 72 h. Transcripts of TNF-α and ER stress marker genes were strongly induced at 1 and 5 μM at all time-points. TNF-α led to induction of mitogen-activated protein kinases (MAPK), as demonstrated by induction of CJUN and CFOS, which form the AP-1 complex. Human primary liver cells reacted more sensitive than Huh7 cells. They showed higher cytotoxicity and induction of TNF-α and ER stress at 2.5 nM, while HepG2 cells were insensitive up to 10 μM due to low expression of organic anion transporting polypeptides. Furthermore, nodularin led to induction of TNF-α protein, and CCAAT/enhancer-binding protein-homologous (CHOP) protein. Our data indicate that nodularin induces inflammation and ER stress and leads to activation of MAPK in liver cells. All of these activated pathways, which were analysed here for the first time in detail, may contribute to the hepatotoxic, and tumorigenic action of nodularin. - Highlights: • Toxicity of nodularin and its mechanisms of action are poorly understood. • We investigated mechanisms of nodularin toxicity in human liver cell lines and human hepatocytes. • We identified several pathways involved in nodularin toxicity. • Nodularin induces TNF-α, MAPK pathway and ER stress • These activated pathways may contribute to the hepatotoxic and tumorigenic action of nodularin.

Nodularin induces tumor necrosis factor-alpha and mitogen-activated protein kinases (MAPK) and leads to induction of endoplasmic reticulum stress

International Nuclear Information System (INIS)

Meili, Nicole; Christen, Verena; Fent, Karl

2016-01-01

Nodularin is produced by the cyanobacterium Nodularia spumigena. It is of concern due to hepatotoxicity in humans and animals. Here we investigated unexplored molecular mechanisms by transcription analysis in human liver cells, focusing on induction of pro-inflammatory cytokines, the tumor necrosis factor α (TNF-α), endoplasmic reticulum (ER) stress and components of the activator protein-1 complex in human hepatoma cells (Huh7) exposed to non-cytotoxic (0.1 and 1 μM) and toxic concentrations (5 μM) for 24, 48, and 72 h. Transcripts of TNF-α and ER stress marker genes were strongly induced at 1 and 5 μM at all time-points. TNF-α led to induction of mitogen-activated protein kinases (MAPK), as demonstrated by induction of CJUN and CFOS, which form the AP-1 complex. Human primary liver cells reacted more sensitive than Huh7 cells. They showed higher cytotoxicity and induction of TNF-α and ER stress at 2.5 nM, while HepG2 cells were insensitive up to 10 μM due to low expression of organic anion transporting polypeptides. Furthermore, nodularin led to induction of TNF-α protein, and CCAAT/enhancer-binding protein-homologous (CHOP) protein. Our data indicate that nodularin induces inflammation and ER stress and leads to activation of MAPK in liver cells. All of these activated pathways, which were analysed here for the first time in detail, may contribute to the hepatotoxic, and tumorigenic action of nodularin. - Highlights: • Toxicity of nodularin and its mechanisms of action are poorly understood. • We investigated mechanisms of nodularin toxicity in human liver cell lines and human hepatocytes. • We identified several pathways involved in nodularin toxicity. • Nodularin induces TNF-α, MAPK pathway and ER stress • These activated pathways may contribute to the hepatotoxic and tumorigenic action of nodularin.

Induction of UMUC+ gene expression in Escherichia coli irradiated by near ultraviolet light

International Nuclear Information System (INIS)

Sato, N.; Ohnishi, T.; Tano, K.; Nozu, K.; Yamamoto, K.

1985-01-01

The induction of umu + gene expression caused by irradiation with near ultraviolet light (BLB; black light blue) was studied in Escherichia coli K-12 strains with special reference to the effects of SOS repair deficiencies. The umuC + gene expression was measured as the enzymic activity of β-galactosidase which is regulated by the promoter of the umuC + operon carried in a plasmid DNA carrying a promoter of umuC + operon, a umuD + gene and a umuC + -lacZ + gene fusion. A high induction of the umuC + gene expression was observed in the uvrA cells in the case of BLB or UV irradiation as compared with the parental wild-type cells. Caffeine inhibited the induction of the umuC + gene expression due to BLB or UV irradiation in both strains. There was very little induction in lexA and recA mutants. In contrast with UV irradiation, there was no killing of cells by BLB irradiation in any strain (wild, uvrA, lexA and recA). Possible implications of the experimental results were discussed. (author)

Inductive matrix completion for predicting gene-disease associations.

Science.gov (United States)

Natarajan, Nagarajan; Dhillon, Inderjit S

2014-06-15

Most existing methods for predicting causal disease genes rely on specific type of evidence, and are therefore limited in terms of applicability. More often than not, the type of evidence available for diseases varies-for example, we may know linked genes, keywords associated with the disease obtained by mining text, or co-occurrence of disease symptoms in patients. Similarly, the type of evidence available for genes varies-for example, specific microarray probes convey information only for certain sets of genes. In this article, we apply a novel matrix-completion method called Inductive Matrix Completion to the problem of predicting gene-disease associations; it combines multiple types of evidence (features) for diseases and genes to learn latent factors that explain the observed gene-disease associations. We construct features from different biological sources such as microarray expression data and disease-related textual data. A crucial advantage of the method is that it is inductive; it can be applied to diseases not seen at training time, unlike traditional matrix-completion approaches and network-based inference methods that are transductive. Comparison with state-of-the-art methods on diseases from the Online Mendelian Inheritance in Man (OMIM) database shows that the proposed approach is substantially better-it has close to one-in-four chance of recovering a true association in the top 100 predictions, compared to the recently proposed Catapult method (second best) that has bigdata.ices.utexas.edu/project/gene-disease. © The Author 2014. Published by Oxford University Press.

Effects of induction heating parameters on controlling residual stress in intermediate size pipes

International Nuclear Information System (INIS)

Rybicki, E.F.; McGuire, P.A.

1981-01-01

Induction heating for stress improvement (IHSI) is a method for reducing the tensile weld induced stresses on the inner surfaces of the girth welded pipes. The process entails inductively heating the outside of a welded pipe while cooling the inner surface with flowing water. A 10-inch schedule 80 Type 304 stainless steel pipe was selected for this study. Residual stresses due to welding were first determined using a finite element computational model. 26 refs

Tumor virus induction: a model for studying gene derepression by light radiation and chemicals

International Nuclear Information System (INIS)

Hellman, K.B.

1981-01-01

Cells of most, if not all, animal species contain information for type C retraviruses. This information is normally repressed, but may be derepressed after cellular exposure to a variety of agents. This phenomenon of virus induction can be utilized to investigate the phenomenon of gene derepression, since control of type C virus induction is thought to be under regulatory processes affecting cellular genes. Properties of type C retraviruses, results of virus induction studies, and discussion of a possible mechanism(s) for virus induction are presented in this review. Utilizing the Al-2 nonproducer cell line, originally derived from cells of the BALB/c mouse, quantitative and kinetic dose-response data have been obtained for type C virus induction by uv radiation, chemicals, and biological agents. Studies showing that protease inhibitors suppress induction suggest the presence of a common mechanism for controlling virus induction; i.e., a protein repressor(s) which acts to control virus gene derepression. Since protease inhibitors suppress induction of prophage in E. coli, similar processes may control virus induction in animal and bacterial systems

Neural Inductive Matrix Completion for Predicting Disease-Gene Associations

KAUST Repository

Hou, Siqing

2018-05-21

In silico prioritization of undiscovered associations can help find causal genes of newly discovered diseases. Some existing methods are based on known associations, and side information of diseases and genes. We exploit the possibility of using a neural network model, Neural inductive matrix completion (NIMC), in disease-gene prediction. Comparing to the state-of-the-art inductive matrix completion method, using neural networks allows us to learn latent features from non-linear functions of input features. Previous methods use disease features only from mining text. Comparing to text mining, disease ontology is a more informative way of discovering correlation of dis- eases, from which we can calculate the similarities between diseases and help increase the performance of predicting disease-gene associations. We compare the proposed method with other state-of-the-art methods for pre- dicting associated genes for diseases from the Online Mendelian Inheritance in Man (OMIM) database. Results show that both new features and the proposed NIMC model can improve the chance of recovering an unknown associated gene in the top 100 predicted genes. Best results are obtained by using both the new features and the new model. Results also show the proposed method does better in predicting associated genes for newly discovered diseases.

Analysis of Stress-Responsive Gene Expression in Cultivated and Weedy Rice Differing in Cold Stress Tolerance.

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Caroline Borges Bevilacqua

Full Text Available Rice (Oryza sativa L. cultivars show impairment of growth in response to environmental stresses such as cold at the early seedling stage. Locally adapted weedy rice is able to survive under adverse environmental conditions, and can emerge in fields from greater soil depth. Cold-tolerant weedy rice can be a good genetic source for developing cold-tolerant, weed-competitive rice cultivars. An in-depth analysis is presented here of diverse indica and japonica rice genotypes, mostly weedy rice, for cold stress response to provide an understanding of different stress adaptive mechanisms towards improvement of the rice crop performance in the field. We have tested a collection of weedy rice genotypes to: 1 classify the subspecies (ssp. grouping (japonica or indica of 21 accessions; 2 evaluate their sensitivity to cold stress; and 3 analyze the expression of stress-responsive genes under cold stress and a combination of cold and depth stress. Seeds were germinated at 25°C at 1.5- and 10-cm sowing depth for 10d. Seedlings were then exposed to cold stress at 10°C for 6, 24 and 96h, and the expression of cold-, anoxia-, and submergence-inducible genes was analyzed. Control plants were seeded at 1.5cm depth and kept at 25°C. The analysis revealed that cold stress signaling in indica genotypes is more complex than that of japonica as it operates via both the CBF-dependent and CBF-independent pathways, implicated through induction of transcription factors including OsNAC2, OsMYB46 and OsF-BOX28. When plants were exposed to cold + sowing depth stress, a complex signaling network was induced that involved cross talk between stresses mediated by CBF-dependent and CBF-independent pathways to circumvent the detrimental effects of stresses. The experiments revealed the importance of the CBF regulon for tolerance to both stresses in japonica and indica ssp. The mechanisms for cold tolerance differed among weedy indica genotypes and also between weedy indica and

The impact of a stress induction task on tic frequencies in youth with Tourette Syndrome.

Science.gov (United States)

Conelea, Christine A; Woods, Douglas W; Brandt, Bryan C

2011-08-01

Tourette Syndrome (TS) is a neuropsychiatric disorder characterized by motor and vocal tics. Tic fluctuations are common and thought to be attributable in part, to contextual variables. Stress is one such variable, but its effects and mechanism of action are poorly understood. The current study measured the effects of a stress induction task on tic frequencies during periods of suppression and non-suppression of tics. Ten youth with TS between the ages of 9 and 17 were exposed to four conditions in random sequence: free-to-tic baseline (BL), reinforced tic suppression (SUP), reinforced tic suppression plus a stress induction task (SUP + STRESS), and a stress induction task alone (STRESS). Tic frequencies did not differ during STRESS and BL. Tic frequencies were greater in SUP + STRESS than SUP. Stress may impact tics through disrupting suppression efforts. Clinically, results suggest that interventions designed to improve tic inhibition in the presence of acute stressors may be beneficial. Copyright © 2011 Elsevier Ltd. All rights reserved.

Stress-induced gene expression and behavior are controlled by DNA methylation and methyl donor availability in the dentate gyrus

Science.gov (United States)

Saunderson, Emily A.; Spiers, Helen; Gutierrez-Mecinas, Maria; Trollope, Alexandra F.; Shaikh, Abeera; Mill, Jonathan; Reul, Johannes M. H. M.

2016-01-01

Stressful events evoke long-term changes in behavioral responses; however, the underlying mechanisms in the brain are not well understood. Previous work has shown that epigenetic changes and immediate-early gene (IEG) induction in stress-activated dentate gyrus (DG) granule neurons play a crucial role in these behavioral responses. Here, we show that an acute stressful challenge [i.e., forced swimming (FS)] results in DNA demethylation at specific CpG (5′-cytosine–phosphate–guanine-3′) sites close to the c-Fos (FBJ murine osteosarcoma viral oncogene homolog) transcriptional start site and within the gene promoter region of Egr-1 (early growth response protein 1) specifically in the DG. Administration of the (endogenous) methyl donor S-adenosyl methionine (SAM) did not affect CpG methylation and IEG gene expression at baseline. However, administration of SAM before the FS challenge resulted in an enhanced CpG methylation at the IEG loci and suppression of IEG induction specifically in the DG and an impaired behavioral immobility response 24 h later. The stressor also specifically increased the expression of the de novo DNA methyltransferase Dnmt3a [DNA (cytosine-5-)-methyltransferase 3 alpha] in this hippocampus region. Moreover, stress resulted in an increased association of Dnmt3a enzyme with the affected CpG loci within the IEG genes. No effects of SAM were observed on stress-evoked histone modifications, including H3S10p-K14ac (histone H3, phosphorylated serine 10 and acetylated lysine-14), H3K4me3 (histone H3, trimethylated lysine-4), H3K9me3 (histone H3, trimethylated lysine-9), and H3K27me3 (histone H3, trimethylated lysine-27). We conclude that the DNA methylation status of IEGs plays a crucial role in FS-induced IEG induction in DG granule neurons and associated behavioral responses. In addition, the concentration of available methyl donor, possibly in conjunction with Dnmt3a, is critical for the responsiveness of dentate neurons to environmental

The CDK inhibitor p21 is a novel target gene of ATF4 and contributes to cell survival under ER stress.

Science.gov (United States)

Inoue, Yasumichi; Kawachi, Shiori; Ohkubo, Tsubasa; Nagasaka, Mai; Ito, Shogo; Fukuura, Keishi; Itoh, Yuka; Ohoka, Nobumichi; Morishita, Daisuke; Hayashi, Hidetoshi

2017-11-01

Activating transcription factor 4 (ATF4) is well known for its role in the endoplasmic reticulum (ER) stress response. ATF4 also transcriptionally induces multiple effectors that determine cell fate depending on cellular context. In addition, ATF4 can communicate both pro-apoptotic and pro-survival signals. How ATF4 mediates its prosurvival roles, however, requires further investigation. Here, we report that the CDK inhibitor p21 is a novel target gene of ATF4. We identified two ATF4-responsive elements, one of which directly binds ATF4, within the first intron of the p21 gene. Importantly, overexpression of p21 enhances cell survival following ER stress induction, while p21 knockdown increases cell death. These results suggest that p21 induction plays a vital role in the cellular response to ER stress and indicate that p21 is a prosurvival effector of ATF4. © 2017 Federation of European Biochemical Societies.

Making memories of stressful events: a journey along epigenetic, gene transcription and signaling pathways

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Johannes M.H.M. eReul

2014-01-01

Full Text Available Strong psychologically stressful events are known to have a long-lasting impact on behavior. The consolidation of such, largely adaptive, behavioral responses to stressful events involves changes in gene expression in limbic brain regions such as the hippocampus and amygdala. The underlying molecular mechanisms however were until recently unresolved. More than a decade ago we started to investigate the role of these hormones in signaling and epigenetic mechanisms participating in the effects of stress on gene transcription in hippocampal neurons. We discovered a novel, rapid non-genomic mechanism in which glucocorticoids via glucocorticoid receptors (GRs facilitate signaling of the ERK MAPK signaling pathway to the downstream nuclear kinases MSK1 and Elk-1 in dentate gyrus (DG granule neurons. Activation of this signaling pathway results in serine10 (S10 phosphorylation and lysine14 (K14 acetylation at histone H3 (H3S10p-K14ac, leading to the induction of the immediate early genes c-Fos and Egr-1. In addition, we found a role of the DNA methylation status of gene promoters. A series of studies showed that these molecular mechanisms play a critical role in the long-lasting consolidation of behavioral responses in the forced swim test and Morris water maze. Furthermore, an important role of GABA was found in controlling the epigenetic and gene transcriptional responses to psychological stress. Thus, psychologically stressful events evoke a long-term impact on behavior through changes in hippocampal function brought about by distinct glutamatergic and glucocorticoid-driven changes in epigenetic regulation of gene transcription which are modulated by (local GABAergic interneurons and limbic afferent inputs. These epigenetic processes may play an important role in the etiology of stress-related mental disorders such as major depressive and anxiety disorders like PTSD.

Plant responses to environmental stresses-from gene to biotechnology.

Science.gov (United States)

Ahanger, Mohammad Abass; Akram, Nudrat Aisha; Ashraf, Muhammad; Alyemeni, Mohammed Nasser; Wijaya, Leonard; Ahmad, Parvaiz

2017-07-01

Increasing global population, urbanization and industrialization are increasing the rate of conversion of arable land into wasteland. Supplying food to an ever-increasing population is one of the biggest challenges that agriculturalists and plant scientists are currently confronting. Environmental stresses make this situation even graver. Despite the induction of several tolerance mechanisms, sensitive plants often fail to survive under environmental extremes. New technological approaches are imperative. Conventional breeding methods have a limited potential to improve plant genomes against environmental stress. Recently, genetic engineering has contributed enormously to the development of genetically modified varieties of different crops such as cotton, maize, rice, canola and soybean. The identification of stress-responsive genes and their subsequent introgression or overexpression within sensitive crop species are now being widely carried out by plant scientists. Engineering of important tolerance pathways, like antioxidant enzymes, osmolyte accumulation, membrane-localized transporters for efficient compartmentation of deleterious ions and accumulation of essential elements and resistance against pests or pathogens is also an area that has been intensively researched. In this review, the role of biotechnology and its successes, prospects and challenges in developing stress-tolerant crop cultivars are discussed.

Evolution of stress-regulated gene expression in duplicate genes of Arabidopsis thaliana.

Directory of Open Access Journals (Sweden)

Cheng Zou

2009-07-01

Full Text Available Due to the selection pressure imposed by highly variable environmental conditions, stress sensing and regulatory response mechanisms in plants are expected to evolve rapidly. One potential source of innovation in plant stress response mechanisms is gene duplication. In this study, we examined the evolution of stress-regulated gene expression among duplicated genes in the model plant Arabidopsis thaliana. Key to this analysis was reconstructing the putative ancestral stress regulation pattern. By comparing the expression patterns of duplicated genes with the patterns of their ancestors, duplicated genes likely lost and gained stress responses at a rapid rate initially, but the rate is close to zero when the synonymous substitution rate (a proxy for time is > approximately 0.8. When considering duplicated gene pairs, we found that partitioning of putative ancestral stress responses occurred more frequently compared to cases of parallel retention and loss. Furthermore, the pattern of stress response partitioning was extremely asymmetric. An analysis of putative cis-acting DNA regulatory elements in the promoters of the duplicated stress-regulated genes indicated that the asymmetric partitioning of ancestral stress responses are likely due, at least in part, to differential loss of DNA regulatory elements; the duplicated genes losing most of their stress responses were those that had lost more of the putative cis-acting elements. Finally, duplicate genes that lost most or all of the ancestral responses are more likely to have gained responses to other stresses. Therefore, the retention of duplicates that inherit few or no functions seems to be coupled to neofunctionalization. Taken together, our findings provide new insight into the patterns of evolutionary changes in gene stress responses after duplication and lay the foundation for testing the adaptive significance of stress regulatory changes under highly variable biotic and abiotic environments.

Long term effect of curcumin in regulation of glycolytic pathway and angiogenesis via modulation of stress activated genes in prevention of cancer.

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Laxmidhar Das

Full Text Available Oxidative stress, an important factor in modulation of glycolytic pathway and induction of stress activated genes, is further augmented due to reduced antioxidant defense system, which promotes cancer progression via inducing angiogenesis. Curcumin, a naturally occurring chemopreventive phytochemical, is reported to inhibit carcinogenesis in various experimental animal models. However, the underlying mechanism involved in anticarcinogenic action of curcumin due to its long term effect is still to be reported because of its rapid metabolism, although metabolites are accumulated in tissues and remain for a longer time. Therefore, the long term effect of curcumin needs thorough investigation. The present study aimed to analyze the anticarcinogenic action of curcumin in liver, even after withdrawal of treatment in Dalton's lymphoma bearing mice. Oxidative stress observed during lymphoma progression reduced antioxidant enzyme activities, and induced angiogenesis as well as activation of early stress activated genes and glycolytic pathway. Curcumin treatment resulted in activation of antioxidant enzyme super oxide dismutase and down regulation of ROS level as well as activity of ROS producing enzyme NADPH:oxidase, expression of stress activated genes HIF-1α, cMyc and LDH activity towards normal level. Further, it lead to significant inhibition of angiogenesis, observed via MMPs activity, PKCα and VEGF level, as well as by matrigel plug assay. Thus findings of this study conclude that the long term effect of curcumin shows anticarcinogenic potential via induction of antioxidant defense system and inhibition of angiogenesis via down regulation of stress activated genes and glycolytic pathway in liver of lymphoma bearing mice.

Genes and Gene Networks Involved in Sodium Fluoride-Elicited Cell Death Accompanying Endoplasmic Reticulum Stress in Oral Epithelial Cells

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Yoshiaki Tabuchi

2014-05-01

Full Text Available Here, to understand the molecular mechanisms underlying cell death induced by sodium fluoride (NaF, we analyzed gene expression patterns in rat oral epithelial ROE2 cells exposed to NaF using global-scale microarrays and bioinformatics tools. A relatively high concentration of NaF (2 mM induced cell death concomitant with decreases in mitochondrial membrane potential, chromatin condensation and caspase-3 activation. Using 980 probe sets, we identified 432 up-regulated and 548 down-regulated genes, that were differentially expressed by >2.5-fold in the cells treated with 2 mM of NaF and categorized them into 4 groups by K-means clustering. Ingenuity® pathway analysis revealed several gene networks from gene clusters. The gene networks Up-I and Up-II included many up-regulated genes that were mainly associated with the biological function of induction or prevention of cell death, respectively, such as Atf3, Ddit3 and Fos (for Up-I and Atf4 and Hspa5 (for Up-II. Interestingly, knockdown of Ddit3 and Hspa5 significantly increased and decreased the number of viable cells, respectively. Moreover, several endoplasmic reticulum (ER stress-related genes including, Ddit3, Atf4 and Hapa5, were observed in these gene networks. These findings will provide further insight into the molecular mechanisms of NaF-induced cell death accompanying ER stress in oral epithelial cells.

Global analysis of host response to induction of a latent bacteriophage

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Keasling Jay D

2007-08-01

Full Text Available Abstract Background The transition from viral latency to lytic growth involves complex interactions among host and viral factors, and the extent to which host physiology is buffered from the virus during induction of lysis is not known. A reasonable hypothesis is that the virus should be evolutionarily selected to ensure host health throughout induction to minimize its chance of reproductive failure. To address this question, we collected transcriptional profiles of Escherichia coli and bacteriophage lambda throughout lysogenic induction by UV light. Results We observed a temporally coordinated program of phage gene expression, with distinct early, middle and late transcriptional classes. Our study confirmed known host-phage interactions of induction of the heat shock regulon, escape replication, and suppression of genes involved in cell division and initiation of replication. We identified 728 E. coli genes responsive to prophage induction, which included pleiotropic stress response pathways, the Arc and Cpx regulons, and global regulators crp and lrp. Several hundred genes involved in central metabolism, energy metabolism, translation and transport were down-regulated late in induction. Though statistically significant, most of the changes in these genes were mild, with only 140 genes showing greater than two-fold change. Conclusion Overall, we observe that prophage induction has a surprisingly low impact on host physiology. This study provides the first global dynamic picture of how host processes respond to lambda phage induction.

Induction of the Wnt antagonist Dickkopf-1 is involved in stress-induced hippocampal damage.

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Francesco Matrisciano

Full Text Available The identification of mechanisms that mediate stress-induced hippocampal damage may shed new light into the pathophysiology of depressive disorders and provide new targets for therapeutic intervention. We focused on the secreted glycoprotein Dickkopf-1 (Dkk-1, an inhibitor of the canonical Wnt pathway, involved in neurodegeneration. Mice exposed to mild restraint stress showed increased hippocampal levels of Dkk-1 and reduced expression of β-catenin, an intracellular protein positively regulated by the canonical Wnt signalling pathway. In adrenalectomized mice, Dkk-1 was induced by corticosterone injection, but not by exposure to stress. Corticosterone also induced Dkk-1 in mouse organotypic hippocampal cultures and primary cultures of hippocampal neurons and, at least in the latter model, the action of corticosterone was reversed by the type-2 glucocorticoid receptor antagonist mifepristone. To examine whether induction of Dkk-1 was causally related to stress-induced hippocampal damage, we used doubleridge mice, which are characterized by a defective induction of Dkk-1. As compared to control mice, doubleridge mice showed a paradoxical increase in basal hippocampal Dkk-1 levels, but no Dkk-1 induction in response to stress. In contrast, stress reduced Dkk-1 levels in doubleridge mice. In control mice, chronic stress induced a reduction in hippocampal volume associated with neuronal loss and dendritic atrophy in the CA1 region, and a reduced neurogenesis in the dentate gyrus. Doubleridge mice were resistant to the detrimental effect of chronic stress and, instead, responded to stress with increases in dendritic arborisation and neurogenesis. Thus, the outcome of chronic stress was tightly related to changes in Dkk-1 expression in the hippocampus. These data indicate that induction of Dkk-1 is causally related to stress-induced hippocampal damage and provide the first evidence that Dkk-1 expression is regulated by corticosteroids in the central

Genome-Wide Identification and Expression Analyses of Aquaporin Gene Family during Development and Abiotic Stress in Banana

Science.gov (United States)

Hu, Wei; Hou, Xiaowan; Huang, Chao; Yan, Yan; Tie, Weiwei; Ding, Zehong; Wei, Yunxie; Liu, Juhua; Miao, Hongxia; Lu, Zhiwei; Li, Meiying; Xu, Biyu; Jin, Zhiqiang

2015-01-01

Aquaporins (AQPs) function to selectively control the flow of water and other small molecules through biological membranes, playing crucial roles in various biological processes. However, little information is available on the AQP gene family in bananas. In this study, we identified 47 banana AQP genes based on the banana genome sequence. Evolutionary analysis of AQPs from banana, Arabidopsis, poplar, and rice indicated that banana AQPs (MaAQPs) were clustered into four subfamilies. Conserved motif analysis showed that all banana AQPs contained the typical AQP-like or major intrinsic protein (MIP) domain. Gene structure analysis suggested the majority of MaAQPs had two to four introns with a highly specific number and length for each subfamily. Expression analysis of MaAQP genes during fruit development and postharvest ripening showed that some MaAQP genes exhibited high expression levels during these stages, indicating the involvement of MaAQP genes in banana fruit development and ripening. Additionally, some MaAQP genes showed strong induction after stress treatment and therefore, may represent potential candidates for improving banana resistance to abiotic stress. Taken together, this study identified some excellent tissue-specific, fruit development- and ripening-dependent, and abiotic stress-responsive candidate MaAQP genes, which could lay a solid foundation for genetic improvement of banana cultivars. PMID:26307965

Induction of cytochrome P450 1 genes and stress response genes in developing zebrafish exposed to ultraviolet radiation

Energy Technology Data Exchange (ETDEWEB)

Behrendt, Lars [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States); Joensson, Maria E. [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States); Department of Environmental Toxicology, Uppsala University (Sweden); Goldstone, Jared V. [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States); Stegeman, John J., E-mail: jstegeman@whoi.edu [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States)

2010-06-01

Ultraviolet (UV) radiation damages cell molecules, and has been suggested to up-regulate mammalian cytochrome P4501 (CYP1) genes through an aryl hydrocarbon receptor (AHR) mediated mechanism. In this study, embryos and larvae of zebrafish (Danio rerio) were exposed to UV to determine the effects on expression of CYP1 and stress response genes in vivo in these fish. Zebrafish embryos were exposed for varying times to UV on two consecutive days, with exposure beginning at 24 and 48 h post-fertilization (hpf). Embryos exposed for 2, 4 or 6 h twice over 2 days to UVB (0.62 W/m{sup 2}; 8.9-26.7 kJ/m{sup 2}) plus UVA (2.05 W/m{sup 2}; 29.5-144.6 kJ/m{sup 2}) had moderately (2.4 {+-} 0.8-fold) but significantly up-regulated levels of CYP1A. UVA alone had no effect on CYP1A expression. Proliferating cellular nuclear antigen (PCNA) and Cu-Zn superoxide dismutase (SOD1) transcript levels were induced (2.1 {+-} 0.2 and 2.3 {+-} 0.5-fold, respectively) in embryos exposed to two 6-h pulses of 0.62 W/m{sup 2} UVB (26.8 kJ/m{sup 2}). CYP1A was induced also in embryos exposed to higher intensity UVB (0.93 W/m{sup 2}) for two 3-h or two 4-h pulses (20.1 or 26.8 kJ/m{sup 2}). CYP1B1, SOD1 and PCNA expression was induced by the two 3-h pulses of the higher intensity UVB, but not after two 4-h pulses of the higher intensity UVB, possibly due to impaired condition of surviving embryos, reflected in a mortality of 34% at that UVB dose. A single 8-h long exposure of zebrafish larvae (8 dpf) to UVB at 0.93 W/m{sup 2} (26.8 kJ/m{sup 2}) significantly induced CYP1A and CYP1B1 expression, but other CYP1 genes (CYP1C1, CYP1C2 and CYP1D1) showed no significant increase. The results show that UVB can induce expression of CYP1 genes as well stress response genes in developing zebrafish, and that UVB intensity and duration influence the responses.

Radiation oxidative stress in cancer induction and prevention

International Nuclear Information System (INIS)

Meher, Prabodha Kumar; Mishra, Kaushala Prasad

2017-01-01

Exposure of cells to ionizing radiation causes generation of intracellular reactive oxygen species (ROS) which are implicated in the mechanism of carcinogenesis. Molecular steps involved in the transformation of normal cells to cancer cells have been enigmatic but generally believed to arise from aberration in cellular redox homeostasis. In normal cell function, a delicate balance is maintained between ROS generated in the metabolic process and level of endogenous antioxidant defense. ROS are known to regulate various cellular functions, such as cell division, signal transduction, and apoptosis. Cells experience oxidative stress when excess production of ROS occurs inside a cell upon exposure to external stress or agents. This redox imbalance affects the cellular functions due to DNA strand breaks, chromosomal aberrations, gene mutations, alteration in signal transduction, and inhibition of apoptosis leading to induction of cancer and other diseases. Radiation-induced ROS are involved in initiation and promotion of carcinogenesis. Therefore, detoxification of ROS by exogenous antioxidants including dietary polyphenols offers an important strategy for cancer prevention. Recent research results have shown that resistance of cancer stem cells to therapies is linked to low level of ROS. Interestingly, in vitro and in vivo experiments have reported that radiotherapy- and chemotherapy-induced ROS in cytosol sensitize the tumor cells to death, resulting in tumor growth retardation. This review is an attempt to delineate mechanisms of ROS in carcinogenesis and prevention by dietary compounds. Natural polyphenols and dietary antioxidants hold potential to prevent cancer. Interventions in ROS-mediated signal alteration, apoptosis activation, and modulation of epigenetic processes may offer effective cancer prevention strategy. (author)

Induction of neutral trehalase Nth1 by heat and osmotic stress is controlled by STRE elements and Msn2/Msn4 transcription factors: variations of PKA effect during stress and growth.

Science.gov (United States)

Zähringer, H; Thevelein, J M; Nwaka, S

2000-01-01

Saccharomyces cerevisiae neutral trehalase, encoded by NTH1, controls trehalose hydrolysis in response to multiple stress conditions, including nutrient limitation. The presence of three stress responsive elements (STREs, CCCCT) in the NTH1 promoter suggested that the transcriptional activator proteins Msn2 and Msn4, as well as the cAMP-dependent protein kinase (PKA), control the stress-induced expression of Nth1. Here, we give direct evidence that Msn2/Msn4 and the STREs control the heat-, osmotic stress- and diauxic shift-dependent induction of Nth1. Disruption of MSN2 and MSN4 abolishes or significantly reduces the heat- and NaCl-induced increases in Nth1 activity and transcription. Stress-induced increases in activity of a lacZ reporter gene put under control of the NTH1 promoter is nearly absent in the double mutant. In all instances, basal expression is also reduced by about 50%. The trehalose concentration in the msn2 msn4 double mutant increases less during heat stress and drops more slowly during recovery than in wild-type cells. This shows that Msn2/Msn4-controlled expression of enzymes of trehalose synthesis and hydrolysis help to maintain trehalose concentration during stress. However, the Msn2/Msn4-independent mechanism exists for heat control of trehalose metabolism. Site-directed mutagenesis of the three STREs (CCCCT changed to CATCT) in NTH1 promoter fused to a reporter gene indicates that the relative proximity of STREs to each other is important for the function of NTH1. Elimination of the three STREs abolishes the stress-induced responses and reduces basal expression by 30%. Contrary to most STRE-regulated genes, the PKA effect on the induction of NTH1 by heat and sodium chloride is variable. During diauxic growth, NTH1 promoter-controlled reporter activity strongly increases, as opposed to the previously observed decrease in Nth1 activity, suggesting a tight but opposite control of the enzyme at the transcriptional and post-translational levels

Induction of Protective Genes Leads to Islet Survival and Function

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Hongjun Wang

2011-01-01

Full Text Available Islet transplantation is the most valid approach to the treatment of type 1 diabetes. However, the function of transplanted islets is often compromised since a large number of β cells undergo apoptosis induced by stress and the immune rejection response elicited by the recipient after transplantation. Conventional treatment for islet transplantation is to administer immunosuppressive drugs to the recipient to suppress the immune rejection response mounted against transplanted islets. Induction of protective genes in the recipient (e.g., heme oxygenase-1 (HO-1, A20/tumor necrosis factor alpha inducible protein3 (tnfaip3, biliverdin reductase (BVR, Bcl2, and others or administration of one or more of the products of HO-1 to the donor, the islets themselves, and/or the recipient offers an alternative or synergistic approach to improve islet graft survival and function. In this perspective, we summarize studies describing the protective effects of these genes on islet survival and function in rodent allogeneic and xenogeneic transplantation models and the prevention of onset of diabetes, with emphasis on HO-1, A20, and BVR. Such approaches are also appealing to islet autotransplantation in patients with chronic pancreatitis after total pancreatectomy, a procedure that currently only leads to 1/3 of transplanted patients being diabetes-free.

Permethrin induction of multiple cytochrome P450 genes in insecticide resistant mosquitoes, Culex quinquefasciatus.

Science.gov (United States)

Gong, Youhui; Li, Ting; Zhang, Lee; Gao, Xiwu; Liu, Nannan

2013-01-01

The expression of some insect P450 genes can be induced by both exogenous and endogenous compounds and there is evidence to suggest that multiple constitutively overexpressed P450 genes are co-responsible for the development of resistance to permethrin in resistant mosquitoes. This study characterized the permethrin induction profiles of P450 genes known to be constitutively overexpressed in resistant mosquitoes, Culex quinquefasciatus. The gene expression in 7 of the 19 P450 genes CYP325K3v1, CYP4D42v2, CYP9J45, (CYP) CPIJ000926, CYP325G4, CYP4C38, CYP4H40 in the HAmCqG8 strain, increased more than 2-fold after exposure to permethrin at an LC50 concentration (10 ppm) compared to their acetone treated counterpart; no significant differences in the expression of these P450 genes in susceptible S-Lab mosquitoes were observed after permethrin treatment. Eleven of the fourteen P450 genes overexpressed in the MAmCqG6 strain, CYP9M10, CYP6Z12, CYP9J33, CYP9J43, CYP9J34, CYP306A1, CYP6Z15, CYP9J45, CYPPAL1, CYP4C52v1, CYP9J39, were also induced more than doubled after exposure to an LC50 (0.7 ppm) dose of permethrin. No significant induction in P450 gene expression was observed in the susceptible S-Lab mosquitoes after permethrin treatment except for CYP6Z15 and CYP9J39, suggesting that permethrin induction of these two P450 genes are common to both susceptible and resistant mosquitoes while the induction of the others are specific to insecticide resistant mosquitoes. These results demonstrate that multiple P450 genes are co-up-regulated in insecticide resistant mosquitoes through both constitutive overexpression and induction mechanisms, providing additional support for their involvement in the detoxification of insecticides and the development of insecticide resistance.

Residual stresses in surface induction hardening of steels: Comparison between experiment and simulation

International Nuclear Information System (INIS)

Coupard, Dominique; Palin-luc, Thierry; Bristiel, Philippe; Ji, Vincent; Dumas, Christian

2008-01-01

Deep induction hardening has been performed on two batches of smooth cylindrical specimens with a hardening depth respectively around 2 mm and 3 mm. The distributions of axial and circumferential residual stresses are analysed for the two specimen batches by X-ray diffraction technique. The radial normal stress field is estimated through the use of the well known Moore and Evans correction. Finally, the experimental residual stresses are compared with those obtained from a multiphysic finite element modelling of the whole induction treatment process, including electromagnetic, thermal, metallurgical and mechanical phenomena. The simulated residual stress field is in good agreement with X-ray analysis especially at depths lower than one-tenth the specimen diameter. At deeper depths, a correction of the experimental X-ray analysis has been done to obtain realistic values

Induction of innate immune genes in brain create the neurobiology of addiction.

Science.gov (United States)

Crews, F T; Zou, Jian; Qin, Liya

2011-06-01

Addiction occurs through repeated abuse of drugs that progressively reduce behavioral control and cognitive flexibility while increasing limbic negative emotion. Recent discoveries indicate neuroimmune signaling underlies addiction and co-morbid depression. Low threshold microglia undergo progressive stages of innate immune activation involving astrocytes and neurons with repeated drug abuse, stress, and/or cell damage signals. Increased brain NF-κB transcription of proinflammatory chemokines, cytokines, oxidases, proteases, TLR and other genes create loops amplifying NF-κB transcription and innate immune target gene expression. Human post-mortem alcoholic brain has increased NF-κB and NF-κB target gene message, increased microglial markers and chemokine-MCP1. Polymorphisms of human NF-κB1 and other innate immune genes contribute to genetic risk for alcoholism. Animal transgenic and genetic studies link NF-κB innate immune gene expression to alcohol drinking. Human drug addicts show deficits in behavioral flexibility modeled pre-clinically using reversal learning. Binge alcohol, chronic cocaine, and lesions link addiction neurobiology to frontal cortex, neuroimmune signaling and loss of behavioral flexibility. Addiction also involves increasing limbic negative emotion and depression-like behavior that is reflected in hippocampal neurogenesis. Innate immune activation parallels loss of neurogenesis and increased depression-like behavior. Protection against loss of neurogenesis and negative affect by anti-oxidant, anti-inflammatory, anti-depressant, opiate antagonist and abstinence from ethanol dependence link limbic affect to changes in innate immune signaling. The hypothesis that innate immune gene induction underlies addiction and affective disorders creates new targets for therapy. Copyright © 2011 Elsevier Inc. All rights reserved.

Nitric Oxide- and Hydrogen Peroxide-Responsive Gene Regulation during Cell Death Induction in Tobacco1[W

Science.gov (United States)

Zago, Elisa; Morsa, Stijn; Dat, James F.; Alard, Philippe; Ferrarini, Alberto; Inzé, Dirk; Delledonne, Massimo; Van Breusegem, Frank

2006-01-01

Nitric oxide (NO) and hydrogen peroxide (H2O2) are regulatory molecules in various developmental processes and stress responses. Tobacco (Nicotiana tabacum) leaves exposed to moderate high light dramatically potentiated NO-mediated cell death in catalase-deficient (CAT1AS) but not in wild-type plants, providing genetic evidence for a partnership between NO and H2O2 during the induction of programmed cell death. With this experimental model system, the specific impact on gene expression was characterized by either NO or H2O2 alone or both molecules combined. By means of genome-wide cDNA-amplified fragment length polymorphism analysis, transcriptional changes were compared in high light-treated CAT1AS and wild-type leaves treated with or without the NO donor sodium nitroprusside. Differential gene expression was detected for 214 of the approximately 8,000 transcript fragments examined. For 108 fragments, sequence analysis revealed homology to genes with a role in signal transduction, defense response, hormone interplay, proteolysis, transport, and metabolism. Surprisingly, only 16 genes were specifically induced by the combined action of NO and H2O2, whereas the majority were regulated by either of them alone. At least seven transcription factors were mutually up-regulated, indicating significant overlap between NO and H2O2 signaling pathways. These results consolidate significant cross-talk between NO and H2O2, provide new insight into the early transcriptional response of plants to increased NO and H2O2 levels, and identify target genes of the combined action of NO and H2O2 during the induction of plant cell death. PMID:16603664

Plant Core Environmental Stress Response Genes Are Systemically Coordinated during Abiotic Stresses

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Kenneth W. Berendzen

2013-04-01

Full Text Available Studying plant stress responses is an important issue in a world threatened by global warming. Unfortunately, comparative analyses are hampered by varying experimental setups. In contrast, the AtGenExpress abiotic stress experiment displays intercomparability. Importantly, six of the nine stresses (wounding, genotoxic, oxidative, UV-B light, osmotic and salt can be examined for their capacity to generate systemic signals between the shoot and root, which might be essential to regain homeostasis in Arabidopsis thaliana. We classified the systemic responses into two groups: genes that are regulated in the non-treated tissue only are defined as type I responsive and, accordingly, genes that react in both tissues are termed type II responsive. Analysis of type I and II systemic responses suggest distinct functionalities, but also significant overlap between different stresses. Comparison with salicylic acid (SA and methyl-jasmonate (MeJA responsive genes implies that MeJA is involved in the systemic stress response. Certain genes are predominantly responding in only one of the categories, e.g., WRKY genes respond mainly non-systemically. Instead, genes of the plant core environmental stress response (PCESR, e.g., ZAT10, ZAT12, ERD9 or MES9, are part of different response types. Moreover, several PCESR genes switch between the categories in a stress-specific manner.

Ultraviolet and environmental stresses involved in the induction and ...

African Journals Online (AJOL)

Light is one of the most important environmental factors regulating plant development and genes expression. Ultraviolet takes up 7% of sunlight and it stimulates distinct responses in plant. Both UV-A and low influence of UV-B can induce the accumulation of anthocyanin via induction of the expression of anthocyanin ...

DMPD: Type I interferon [corrected] gene induction by the interferon regulatory factorfamily of transcription factors. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 16979567 Type I interferon [corrected] gene induction by the interferon regulatory factorfamily...ng) (.svg) (.html) (.csml) Show Type I interferon [corrected] gene induction by the interferon regulatory factorfamily...orrected] gene induction by the interferon regulatory factorfamily of transcription factors. Authors Honda K

Gene response in rice plants treated with continuous fog influenced by pH, was similar to that treated with biotic stress.

Science.gov (United States)

Satoh, Kouji; Saji, Shoko; Ito, Shoko; Shimizu, Hideyuki; Saji, Hikaru; Kikuchi, Shoshi

2014-01-01

Throughout Asia, including Japan, rice plants are cultivated in a wide range of areas from lowlands to highlands and are frequently exposed to fog, including acid fog. Some physiological studies have shown that acid fog can be a stress factor for plants. We analyzed the gene expression profiles of rice plants treated with artificially prepared simulated acid fog (SiAF) or simulated neutral fog (SiNF) for 1 or 7 days. Microarray analysis results suggested that both the SiAF and the SiNF treatments induced the expression of genes involved in the defense and stress responses in rice plants. Induction of such genes was detected in plants treated with SiAF for 1 day, and the number of induced genes increased in plants treated with SiAF for 7 days. The genes for defense and stress responses were also induced by SiNF for 7 days, although they were not induced by SiNF for 1 day. The gene expression profiles of the SiAF-treated and the SiNF-treated plants were compared to those of plants treated with other stress factors. The comparison revealed that both SiAF and SiNF treatments have similar effects to biotic stresses and ozone stress. The genes encoding NADPH oxidase and germin, which function in apoplasts, were also induced by SiAF, SiNF and biotic stresses. These findings suggest that both the SiAF and the SiNF treatments may result in oxidative stress through the apoplastic production of reactive oxygen species.

Low-power millimeter wave radiations do not alter stress-sensitive gene expression of chaperone proteins.

Science.gov (United States)

Zhadobov, M; Sauleau, R; Le Coq, L; Debure, L; Thouroude, D; Michel, D; Le Dréan, Y

2007-04-01

This article reports experimental results on the influence of low-power millimeter wave (MMW) radiation at 60 GHz on a set of stress-sensitive gene expression of molecular chaperones, namely clusterin (CLU) and HSP70, in a human brain cell line. Selection of the exposure frequency is determined by its near-future applications for the new broadband civil wireless communication systems including wireless local area networks (WLAN) for domestic and professional uses. Frequencies around 60 GHz are strongly attenuated in the earth's atmosphere and such radiations represent a new environmental factor. An exposure system operating in V-band (50-75 GHz) was developed for cell exposure. U-251 MG glial cell line was sham-exposed or exposed to MMW radiation for different durations (1-33 h) and two different power densities (5.4 microW/cm(2) or 0.54 mW/cm(2)). As gene expression is a multiple-step process, we analyzed chaperone proteins induction at different levels. First, using luciferase reporter gene, we investigated potential effect of MMWs on the activation of transcription factors (TFs) and gene promoter activity. Next, using RT-PCR and Western blot assays, we verified whether MMW exposure could alter RNA accumulation, translation, or protein stability. Experimental data demonstrated the absence of significant modifications in gene transcription, mRNA, and protein amount for the considered stress-sensitive genes for the exposure durations and power densities investigated. The main results of this study suggest that low-power 60 GHz radiation does not modify stress-sensitive gene expression of chaperone proteins. (c) 2006 Wiley-Liss, Inc.

Induction of Endoplasmic Reticulum Stress and Unfolded Protein Response Constitutes a Pathogenic Strategy of group A Streptococcus

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Emanuel eHanski

2014-08-01

Full Text Available The connection between bacterial pathogens and unfolded protein response (UPR is poorly explored. In this review we highlight the evidence showing that group A streptococcus (GAS induces endoplasmic reticulum (ER stress and UPR through which it captures the amino acid asparagine (ASN from the host. GAS acts extracellularly and during adherence to host cells it delivers the hemolysin toxins; streptolysin O (SLO and streptolysin S (SLS. By poorly understood pathways, these toxins trigger UPR leading to the induction of the transcriptional regulator ATF4 and consequently to the upregulation of asparagine synthetase (ASNS transcription leading to production and release of ASN. GAS senses ASN and alters gene expression profile accordingly, and increases the rate of multiplication. We suggest that induction of UPR by GAS and by other bacterial pathogens represent means through which bacterial pathogens gain nutrients from the host, obviating the need to become internalized or inflict irreversible cell damage.

Profilin is required for viral morphogenesis, syncytium formation, and cell-specific stress fiber induction by respiratory syncytial virus

Directory of Open Access Journals (Sweden)

Barik Sailen

2003-05-01

Full Text Available Abstract Background Actin is required for the gene expression and morphogenesis of respiratory syncytial virus (RSV, a clinically important Pneumovirus of the Paramyxoviridae family. In HEp-2 cells, RSV infection also induces actin stress fibers, which may be important in the immunopathology of the RSV disease. Profilin, a major regulator of actin polymerization, stimulates viral transcription in vitro. Thus, we tested the role of profilin in RSV growth and RSV-actin interactions in cultured cells (ex vivo. Results We tested three cell lines: HEp-2 (human, A549 (human, and L2 (rat. In all three, RSV grew well and produced fused cells (syncytium, and two RSV proteins, namely, the phosphoprotein P and the nucleocapsid protein N, associated with profilin. In contrast, induction of actin stress fibers by RSV occurred in HEp-2 and L2 cells, but not in A549. Knockdown of profilin by RNA interference had a small effect on viral macromolecule synthesis but strongly inhibited maturation of progeny virions, cell fusion, and induction of stress fibers. Conclusions Profilin plays a cardinal role in RSV-mediated cell fusion and viral maturation. In contrast, interaction of profilin with the viral transcriptional proteins P and N may only nominally activate viral RNA-dependent RNA polymerase. Stress fiber formation is a cell-specific response to infection, requiring profilin and perhaps other signaling molecules that are absent in certain cell lines. Stress fibers per se play no role in RSV replication in cell culture. Clearly, the cellular architecture controls multiple steps of host-RSV interaction, some of which are regulated by profilin.

Water quality assessment using the AREc32 reporter gene assay indicative of the oxidative stress response pathway.

Science.gov (United States)

Escher, Beate I; Dutt, Mriga; Maylin, Erin; Tang, Janet Y M; Toze, Simon; Wolf, C Roland; Lang, Matti

2012-11-01

The reporter gene assay AREc32 is based on the induction of the Nrf2 mediated oxidative stress response pathway in the human breast cancer cell line MCF7, where eight copies of the antioxidant response element (ARE) are linked to a reporter gene encoding for luciferase. The Nrf2-ARE pathway is responsive to many chemicals that cause oxidative stress, among them a large number of pesticides and skin irritants. We adopted and validated the AREc32 bioassay for water quality testing. tert-Butylhydroquinone served as the positive control, phenol as the negative control and other reactive chemicals were assessed for their specificity. An environmentally relevant reference chemical, benzo(a)pyrene was the most potent inducer of all tested chemicals. The concentration causing an induction ratio (IR) of 1.5 (EC(IR1.5)) was chosen as the effect benchmark value. The assay was applied to 21 water samples ranging from sewage to drinking water, including secondary treatment and various tertiary treatment options (ozonation, biologically activated carbon filtration, membrane filtration, reverse osmosis, advanced oxidation, chlorination, chloramination). The samples were enriched by solid phase extraction. In most samples the oxidative stress response was far more sensitive than cytotoxicity. The primary and secondary treated effluent exceeded the effect threshold IR 1.5 at a relative enrichment factor (REF) of 1, i.e., the native samples were active. All tertiary treated samples were less potent and their EC(IR1.5) lay between REF 1 and 10. The Nrf2 pathway was induced at a REF of approximately 10 for surface waters and drinking water, and above this enrichment cytotoxicity took over in most samples and quenched the induction. The blank (ultrapure water run through the sample enrichment process) was cytotoxic at an REF of 100, which is the limit of concentrations range that can be evaluated. Treatment typically decreased both the cytotoxicity and oxidative stress response apart

Exercise improves cognitive responses to psychological stress through enhancement of epigenetic mechanisms and gene expression in the dentate gyrus.

Directory of Open Access Journals (Sweden)

Andrew Collins

Full Text Available We have shown previously that exercise benefits stress resistance and stress coping capabilities. Furthermore, we reported recently that epigenetic changes related to gene transcription are involved in memory formation of stressful events. In view of the enhanced coping capabilities in exercised subjects we investigated epigenetic, gene expression and behavioral changes in 4-weeks voluntarily exercised rats.Exercised and control rats coped differently when exposed to a novel environment. Whereas the control rats explored the new cage for the complete 30-min period, exercised animals only did so during the first 15 min after which they returned to sleeping or resting behavior. Both groups of animals showed similar behavioral responses in the initial forced swim session. When re-tested 24 h later however the exercised rats showed significantly more immobility behavior and less struggling and swimming. If rats were killed at 2 h after novelty or the initial swim test, i.e. at the peak of histone H3 phospho-acetylation and c-Fos induction, then the exercised rats showed a significantly higher number of dentate granule neurons expressing the histone modifications and immediate-early gene induction.Thus, irrespective of the behavioral response in the novel cage or initial forced swim session, the impact of the event at the dentate gyrus level was greater in exercised rats than in control animals. Furthermore, in view of our concept that the neuronal response in the dentate gyrus after forced swimming is involved in memory formation of the stressful event, the observations in exercised rats of enhanced neuronal responses as well as higher immobility responses in the re-test are consistent with the reportedly improved cognitive performance in these animals. Thus, improved stress coping in exercised subjects seems to involve enhanced cognitive capabilities possibly resulting from distinct epigenetic mechanisms in dentate gyrus neurons.

Induction of heat shock proteins DnaK, GroEL, and GroES by salt stress in Lactococcus lactis

DEFF Research Database (Denmark)

Kilstrup, Mogens; Jacobsen, Susanne; Hammer, Karin

1997-01-01

The bacterium Lactococcus lactis has become a model organism in studies of growth physiology and membrane transport, as a result of its simple fermentative metabolism. It is also used as a model for studying the importance of specific genes and functions during lie in excess nutrients, by compari...... the timing during heat stress although at a lower induction level. These data indicate an overlap between the heat shock and salt stress responses in L. lactis......., by comparison of prototrophic wild-type strains and auxotrophic domesticated (daily) strains. In a study of the capacity of domesticated strains to perform directed responses toward various stress conditions, we have analyzed the heat and salt stress response in the established L,. lactis subsp. cremoris...... laboratory strain MG1363, which was originally derived from a dairy strain, After two-dimensional separation of proteins, the DnaK, GroEL, and GroES heat shock proteins, the HrcA (Orf1) heat shack repressor, and the glycolytic enzymes pyruvate kinase, glyceral-dehyde-3-phosphate dehydrogenase...

Mechanism of Gene Expression of Arabidopsis Glutathione S-Transferase, AtGST1, and AtGST11 in Response to Aluminum Stress1

Science.gov (United States)

Ezaki, Bunichi; Suzuki, Masakatsu; Motoda, Hirotoshi; Kawamura, Masako; Nakashima, Susumu; Matsumoto, Hideaki

2004-01-01

The gene expression of two Al-induced Arabidopsis glutathione S-transferase genes, AtGST1 and AtGST11, was analyzed to investigate the mechanism underlying the response to Al stress. An approximately 1-kb DNA fragment of the 5′-upstream region of each gene was fused to a β-glucuronidase (GUS) reporter gene (pAtGST1::GUS and pAtGST11::GUS) and introduced into Arabidopsis ecotype Landsberg erecta. The constructed transgenic lines showed a time-dependent gene expression to a different degree in the root and/or leaf by Al stress. The pAtGST1::GUS gene was induced after a short Al treatment (maximum expression after a 2-h exposure), while the pAtGST11::GUS gene was induced by a longer Al treatment (approximately 8 h for maximum expression). Since the gene expression was observed in the leaf when only the root was exposed to Al stress, a signaling system between the root and shoot was suggested in Al stress. A GUS staining experiment using an adult transgenic line carrying the pAtGST11::GUS gene supported this suggestion. Furthermore, Al treatment simultaneously with various Ca depleted conditions in root region enhanced the gene expression of the pAtGST11::GUS in the shoot region. This result suggested that the degree of Al toxicity in the root reflects the gene response of pAtGST11::GUS in the shoot via the deduced signaling system. Both transgenic lines also showed an increase of GUS activity after cold stress, heat stress, metal toxicity, and oxidative damages, suggesting a common induction mechanism in response to the tested stresses including Al stress. PMID:15047894

Gene expression and apoptosis induction in p53-heterozygous irradiated mice

International Nuclear Information System (INIS)

Di Masi, Alessandra; Antoccia, Antonio; Dimauro, Ivan; Argentino-Storino, Alberta; Mosiello, Alberto; Mango, Ruggiero; Novelli, Giuseppe; Tanzarella, Caterina

2006-01-01

The role of the p53-genetic background in the expression of genes involved in either cell cycle checkpoint activation or apoptosis was evaluated in p53+/+ and p53+/- mouse strains at both basal levels and after DNA-induced damage. The spleen, colon, kidneys, lungs and liver of both strains were harvested from untreated animals and from mice exposed to 7.5 Gy of X-rays and sacrificed after 5 h. No significant differences were observed in the basal levels of p53 protein, CDKN1A and bax mRNA and spontaneous apoptosis, neither among the different organs within the same strain, nor between the same organ in the p53+/+ and p53+/- strains. After X-ray exposure, p53-dependent regulation was strikingly tissue-specific. In wild-type irradiated mice, p53 protein level increased after radiation treatment in all the organs analysed, whereas both CDKN1A and bax genes transcription increased in the spleen, colon and lungs, as assessed by means of quantitative RT-PCR. In p53+/- irradiated mice, on the contrary, a significant p53 induction was detected only in the spleen, while CDKN1A and bax genes levels increased in the spleen, colon and lungs, revealing the existence of different mechanisms of gene regulation in different organs. Apoptosis induction was observed in the spleen and colon of both strains, even if to lower extent in p53+/- mice compared to p53+/+ animals. In conclusion, in the spleen and colon, target gene transcription and apoptosis may be related to p53 genotype after DNA damage-induction. Moreover, our findings highlight the selectivity of p53 in transactivation following DNA damage in vivo, resulting in tissue-specific responses

Gene expression and apoptosis induction in p53-heterozygous irradiated mice

Energy Technology Data Exchange (ETDEWEB)

Di Masi, Alessandra [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy); Antoccia, Antonio [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy); Dimauro, Ivan [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy); Argentino-Storino, Alberta [Research Toxicology Centre S.p.A., Via Tito Speri, 18, 00040 Pomezia (RM) (Italy); Mosiello, Alberto [Research Toxicology Centre S.p.A., Via Tito Speri, 18, 00040 Pomezia (RM) (Italy); Mango, Ruggiero [Centre of Excellence for Genomic Risk Assessment in Multifactorial and Complex Diseases, School of Medicine, University of Rome ' Tor Vergata' , Rome (Italy); Novelli, Giuseppe [Centre of Excellence for Genomic Risk Assessment in Multifactorial and Complex Diseases, School of Medicine, University of Rome ' Tor Vergata' , Rome (Italy); Tanzarella, Caterina [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy)]. E-mail: tanzarel@uniroma3.it

2006-02-22

The role of the p53-genetic background in the expression of genes involved in either cell cycle checkpoint activation or apoptosis was evaluated in p53+/+ and p53+/- mouse strains at both basal levels and after DNA-induced damage. The spleen, colon, kidneys, lungs and liver of both strains were harvested from untreated animals and from mice exposed to 7.5 Gy of X-rays and sacrificed after 5 h. No significant differences were observed in the basal levels of p53 protein, CDKN1A and bax mRNA and spontaneous apoptosis, neither among the different organs within the same strain, nor between the same organ in the p53+/+ and p53+/- strains. After X-ray exposure, p53-dependent regulation was strikingly tissue-specific. In wild-type irradiated mice, p53 protein level increased after radiation treatment in all the organs analysed, whereas both CDKN1A and bax genes transcription increased in the spleen, colon and lungs, as assessed by means of quantitative RT-PCR. In p53+/- irradiated mice, on the contrary, a significant p53 induction was detected only in the spleen, while CDKN1A and bax genes levels increased in the spleen, colon and lungs, revealing the existence of different mechanisms of gene regulation in different organs. Apoptosis induction was observed in the spleen and colon of both strains, even if to lower extent in p53+/- mice compared to p53+/+ animals. In conclusion, in the spleen and colon, target gene transcription and apoptosis may be related to p53 genotype after DNA damage-induction. Moreover, our findings highlight the selectivity of p53 in transactivation following DNA damage in vivo, resulting in tissue-specific responses.

Silver nanoparticles induce endoplasmatic reticulum stress response in zebrafish

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Christen, Verena [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Capelle, Martinus [Crucell, P.O. Box 2048, NL-2301 Leiden (Netherlands); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich, Department of Environmental Systems Science, CH-8092 Zürich (Switzerland)

2013-10-15

Silver nanoparticles (AgNPs) find increasing applications, and therefore humans and the environment are increasingly exposed to them. However, potential toxicological implications are not sufficiently known. Here we investigate effects of AgNPs (average size 120 nm) on zebrafish in vitro and in vivo, and compare them to human hepatoma cells (Huh7). AgNPs are incorporated in zebrafish liver cells (ZFL) and Huh7, and in zebrafish embryos. In ZFL cells AgNPs lead to induction of reactive oxygen species (ROS), endoplasmatic reticulum (ER) stress response, and TNF-α. Transcriptional alterations also occur in pro-apoptotic genes p53 and Bax. The transcriptional profile differed in ZFL and Huh7 cells. In ZFL cells, the ER stress marker BiP is induced, concomitant with the ER stress marker ATF-6 and spliced XBP-1 after 6 h and 24 h exposure to 0.5 g/L and 0.05 g/L AgNPs, respectively. This indicates the induction of different pathways of the ER stress response. Moreover, AgNPs induce TNF-α. In zebrafish embryos exposed to 0.01, 0.1, 1 and 5 mg/L AgNPs hatching was affected and morphological defects occurred at high concentrations. ER stress related gene transcripts BiP and Synv are significantly up-regulated after 24 h at 0.1 and 5 mg/L AgNPs. Furthermore, transcriptional alterations occurred in the pro-apoptotic genes Noxa and p21. The ER stress response was strong in ZFL cells and occurred in zebrafish embryos as well. Our data demonstrate for the first time that AgNPs lead to induction of ER stress in zebrafish. The induction of ER stress can have several consequences including the activation of apoptotic and inflammatory pathways. - Highlights: • Effects of silver nanoparticles (120 nm AgNPs) are investigated in zebrafish. • AgNPs induce all ER stress reponses in vitro in zebrafish liver cells. • AgNPs induce weak ER stress in zebrafish embryos. • AgNPs induce oxidative stress and transcripts of pro-apoptosis genes.

Silver nanoparticles induce endoplasmatic reticulum stress response in zebrafish

International Nuclear Information System (INIS)

Christen, Verena; Capelle, Martinus; Fent, Karl

2013-01-01

Silver nanoparticles (AgNPs) find increasing applications, and therefore humans and the environment are increasingly exposed to them. However, potential toxicological implications are not sufficiently known. Here we investigate effects of AgNPs (average size 120 nm) on zebrafish in vitro and in vivo, and compare them to human hepatoma cells (Huh7). AgNPs are incorporated in zebrafish liver cells (ZFL) and Huh7, and in zebrafish embryos. In ZFL cells AgNPs lead to induction of reactive oxygen species (ROS), endoplasmatic reticulum (ER) stress response, and TNF-α. Transcriptional alterations also occur in pro-apoptotic genes p53 and Bax. The transcriptional profile differed in ZFL and Huh7 cells. In ZFL cells, the ER stress marker BiP is induced, concomitant with the ER stress marker ATF-6 and spliced XBP-1 after 6 h and 24 h exposure to 0.5 g/L and 0.05 g/L AgNPs, respectively. This indicates the induction of different pathways of the ER stress response. Moreover, AgNPs induce TNF-α. In zebrafish embryos exposed to 0.01, 0.1, 1 and 5 mg/L AgNPs hatching was affected and morphological defects occurred at high concentrations. ER stress related gene transcripts BiP and Synv are significantly up-regulated after 24 h at 0.1 and 5 mg/L AgNPs. Furthermore, transcriptional alterations occurred in the pro-apoptotic genes Noxa and p21. The ER stress response was strong in ZFL cells and occurred in zebrafish embryos as well. Our data demonstrate for the first time that AgNPs lead to induction of ER stress in zebrafish. The induction of ER stress can have several consequences including the activation of apoptotic and inflammatory pathways. - Highlights: • Effects of silver nanoparticles (120 nm AgNPs) are investigated in zebrafish. • AgNPs induce all ER stress reponses in vitro in zebrafish liver cells. • AgNPs induce weak ER stress in zebrafish embryos. • AgNPs induce oxidative stress and transcripts of pro-apoptosis genes

Foxtail millet NF-Y families: genome-wide survey and evolution analyses identified two functional genes important in abiotic stresses

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Zhi-Juan eFeng

2015-12-01

Full Text Available It was reported that Nuclear Factor Y (NF-Y genes were involved in abiotic stress in plants. Foxtail millet (Setaria italica, an elite stress tolerant crop, provided an impetus for the investigation of the NF-Y families in abiotic responses. In the present study, a total of 39 NF-Y genes were identified in foxtail millet. Synteny analyses suggested that foxtail millet NF-Y genes had experienced rapid expansion and strong purifying selection during the process of plant evolution. De novo transcriptome assembly of foxtail millet revealed 11 drought up-regulated NF-Y genes. SiNF-YA1 and SiNF-YB8 were highly activated in leaves and/or roots by drought and salt stresses. Abscisic acid (ABA and H2O2 played positive roles in the induction of SiNF-YA1 and SiNF-YB8 under stress treatments. Transient luciferase (LUC expression assays revealed that SiNF-YA1 and SiNF-YB8 could activate the LUC gene driven by the tobacco (Nicotiana tobacam NtERD10, NtLEA5, NtCAT, NtSOD or NtPOD promoter under normal or stress conditions. Overexpression of SiNF-YA1 enhanced drought and salt tolerance by activating stress-related genes NtERD10 and NtCAT1 and by maintaining relatively stable relative water content (RWC and contents of chlorophyll, superoxide dismutase (SOD, peroxidase (POD, catalase (CAT and malondialdehyde (MDA in transgenic lines under stresses. SiNF-YB8 regulated expression of NtSOD, NtPOD, NtLEA5 and NtERD10 and conferred relatively high RWC and chlorophyll contents and low MDA content, resulting in drought and osmotic tolerance in transgenic lines under stresses. Therefore, SiNF-YA1 and SiNF-YB8 could activate stress-related genes and improve physiological traits, resulting in tolerance to abiotic stresses in plants. All these results will facilitate functional characterization of foxtail millet NF-Ys in future studies.

Liposome-based DNA carriers may induce cellular stress response and change gene expression pattern in transfected cells

Science.gov (United States)

2011-01-01

Background During functional studies on the rat stress-inducible Hspa1b (hsp70.1) gene we noticed that some liposome-based DNA carriers, which are used for transfection, induce its promoter activity. This observation concerned commercial liposome formulations (LA), Lipofectin and Lipofectamine 2000. This work was aimed to understand better the mechanism of this phenomenon and its potential biological and practical consequences. Results We found that a reporter gene driven by Hspa1b promoter is activated both in the case of transient transfections and in the stably transfected cells treated with LA. Using several deletion clones containing different fragments of Hspa1b promoter, we found that the regulatory elements responsible for most efficient LA-driven inducibility were located between nucleotides -269 and +85, relative to the transcription start site. Further studies showed that the induction mechanism was independent of the classical HSE-HSF interaction that is responsible for gene activation during heat stress. Using DNA microarrays we also detected significant activation of the endogenous Hspa1b gene in cells treated with Lipofectamine 2000. Several other stress genes were also induced, along with numerous genes involved in cellular metabolism, cell cycle control and pro-apoptotic pathways. Conclusions Our observations suggest that i) some cationic liposomes may not be suitable for functional studies on hsp promoters, ii) lipofection may cause unintended changes in global gene expression in the transfected cells. PMID:21663599

Liposome-based DNA carriers may induce cellular stress response and change gene expression pattern in transfected cells

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Lisowska Katarzyna Marta

2011-06-01

Full Text Available Abstract Background During functional studies on the rat stress-inducible Hspa1b (hsp70.1 gene we noticed that some liposome-based DNA carriers, which are used for transfection, induce its promoter activity. This observation concerned commercial liposome formulations (LA, Lipofectin and Lipofectamine 2000. This work was aimed to understand better the mechanism of this phenomenon and its potential biological and practical consequences. Results We found that a reporter gene driven by Hspa1b promoter is activated both in the case of transient transfections and in the stably transfected cells treated with LA. Using several deletion clones containing different fragments of Hspa1b promoter, we found that the regulatory elements responsible for most efficient LA-driven inducibility were located between nucleotides -269 and +85, relative to the transcription start site. Further studies showed that the induction mechanism was independent of the classical HSE-HSF interaction that is responsible for gene activation during heat stress. Using DNA microarrays we also detected significant activation of the endogenous Hspa1b gene in cells treated with Lipofectamine 2000. Several other stress genes were also induced, along with numerous genes involved in cellular metabolism, cell cycle control and pro-apoptotic pathways. Conclusions Our observations suggest that i some cationic liposomes may not be suitable for functional studies on hsp promoters, ii lipofection may cause unintended changes in global gene expression in the transfected cells.

Effects of various types of stress on the metabolism of reserve carbohydrates in Saccharomyces cerevisiae: genetic evidence for a stress-induced recycling of glycogen and trehalose.

Science.gov (United States)

Parrou, J L; Teste, M A; François, J

1997-06-01

It is well known that glycogen and trehalose accumulate in yeast under nutrient starvation or entering into the stationary phase of growth, and that high levels of trehalose are found in heat-shocked cells. However, effects of various types of stress on trehalose, and especially on glycogen, are poorly documented. Taking into account that almost all genes encoding the enzymes involved in the metabolism of these two reserve carbohydrates contain between one and several copies of the stress-responsive element (STRE), an investigation was made of the possibility of a link between the potential transcriptional induction of these genes and the accumulation of glycogen and trehalose under different stress conditions. Using transcriptional fusions, it was found that all these genes were induced in a similar fashion, although to various extents, by temperature, osmotic and oxidative stresses. Experiments performed with an msn2/msn4 double mutant proved that the transcriptional induction of the genes encoding glycogen synthase (GSY2) and trehalose-6-phosphate synthase (TPS1) was needed for the small increase in glycogen and trehalose upon exposure to a mild heat stress and salt shock. However, the extent of transcriptional activation of these genes upon stresses in wild-type strains was not correlated with a proportional rise in either glycogen or trehalose. The major explanation for this lack of correlation comes from the fact that genes encoding the enzymes of the biosynthetic and of the biodegradative pathways were almost equally induced. Hence, trehalose and glycogen accumulated to much higher levels in cells lacking neutral trehalose or glycogen phosphorylase exposed to stress conditions, which suggested that one of the major effects of stress in yeast is to induce a wasteful expenditure of energy by increasing the recycling of these molecules. We also found that transcriptional induction of STRE-controlled genes was abolished at temperatures above 40 degree C, while

CANDIDATE GENE ANALYSIS IN ISRAELI SOLDIERS WITH STRESS FRACTURES

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Ran Yanovich

2012-03-01

Full Text Available To investigate the association of polymorphisms within candidate genes which we hypothesized may contribute to stress fracture predisposition, a case-control, cross- sectional study design was employed. Genotyping 268 Single Nucleotide Polymorphisms- SNPs within 17 genes in 385 Israeli young male and female recruits (182 with and 203 without stress fractures. Twenty-five polymorphisms within 9 genes (NR3C1, ANKH, VDR, ROR2, CALCR, IL6, COL1A2, CBG, and LRP4 showed statistically significant differences (p < 0.05 in the distribution between stress fracture cases and non stress fracture controls. Seventeen genetic variants were associated with an increased stress fracture risk, and eight variants with a decreased stress fracture risk. None of the SNP associations remained significant after correcting for multiple comparisons (false discovery rate- FDR. Our findings suggest that genes may be involved in stress fracture pathogenesis. Specifically, the CALCR and the VDR genes are intriguing candidates. The putative involvement of these genes in stress fracture predisposition requires analysis of more cases and controls and sequencing the relevant genomic regions, in order to define the specific gene mutations

Heat stress and sudden infant death syndrome--stress gene expression after exposure to moderate heat stress

DEFF Research Database (Denmark)

Rohde, Marianne Cathrine; Corydon, Thomas Juhl; Hansen, Jakob

2013-01-01

The aim of the present study was to investigate stress gene expression in cultured primary fibroblasts established from Achilles tendons collected during autopsies from sudden infant death syndrome (SIDS) cases, and age-matched controls (infants dying in a traumatic event). Expression of 4 stress...... responsive genes, HSPA1B, HSPD1, HMOX1, and SOD2, was studied by quantitative reverse transcriptase PCR analysis of RNA purified from cells cultured under standard or various thermal stress conditions. The expression of all 4 genes was highly influenced by thermal stress in both SIDS and control cells. High...... interpersonal variance found in the SIDS group indicated that they represented a more heterogeneous group than controls. The SIDS group responded to thermal stress with a higher expression of the HSPA1B and HSPD1 genes compared to the control group, whereas no significant difference was observed...

The dehydration stress of couch grass is associated with its lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA.

Science.gov (United States)

Janská, Anna; Svoboda, Pavel; Spiwok, Vojtěch; Kučera, Ladislav; Ovesná, Jaroslava

2018-05-02

The wild relatives of crop species represent a potentially valuable source of novel genetic variation, particularly in the context of improving the crop's level of tolerance to abiotic stress. The mechanistic basis of these tolerances remains largely unexplored. Here, the focus was to characterize the transcriptomic response of the nodes (meristematic tissue) of couch grass (a relative of barley) to dehydration stress, and to compare it to that of the barley crown formed by both a drought tolerant and a drought sensitive barley cultivar. Many of the genes up-regulated in the nodes by the stress were homologs of genes known to be mediated by abscisic acid during the response to drought, or were linked to either development or lipid metabolism. Transporters also featured prominently, as did genes acting on root architecture. The resilience of the couch grass node arise from both their capacity to develop an altered, more effective root architecture, but also from their formation of a lipid barrier on their outer surface and their ability to modify both their lipid metabolism and transporter activity when challenged by dehydration stress. Our analysis revealed the nature of dehydration stress response in couch grass. We suggested the tolerance is associated with lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA. We also proved the applicability of barley microarray for couch grass stress-response analysis.

Induction of Inducible Nitric Oxide Synthase by Lipopolysaccharide and the Influences of Cell Volume Changes, Stress Hormones and Oxidative Stress on Nitric Oxide Efflux from the Perfused Liver of Air-Breathing Catfish, Heteropneustes fossilis.

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Mahua G Choudhury

Full Text Available The air-breathing singhi catfish (Heteropneustes fossilis is frequently being challenged by bacterial contaminants, and different environmental insults like osmotic, hyper-ammonia, dehydration and oxidative stresses in its natural habitats throughout the year. The main objectives of the present investigation were to determine (a the possible induction of inducible nitric oxide synthase (iNOS gene with enhanced production of nitric oxide (NO by intra-peritoneal injection of lipopolysaccharide (LPS (a bacterial endotoxin, and (b to determine the effects of hepatic cell volume changes due to anisotonicity or by infusion of certain metabolites, stress hormones and by induction of oxidative stress on production of NO from the iNOS-induced perfused liver of singhi catfish. Intra-peritoneal injection of LPS led to induction of iNOS gene and localized tissue specific expression of iNOS enzyme with more production and accumulation of NO in different tissues of singhi catfish. Further, changes of hydration status/cell volume, caused either by anisotonicity or by infusion of certain metabolites such as glutamine plus glycine and adenosine, affected the NO production from the perfused liver of iNOS-induced singhi catfish. In general, increase of hydration status/cell swelling due to hypotonicity caused decrease, and decrease of hydration status/cell shrinkage due to hypertonicity caused increase of NO efflux from the perfused liver, thus suggesting that changes in hydration status/cell volume of hepatic cells serve as a potent modulator for regulating the NO production. Significant increase of NO efflux from the perfused liver was also observed while infusing the liver with stress hormones like epinephrine and norepinephrine, accompanied with decrease of hydration status/cell volume of hepatic cells. Further, oxidative stress, caused due to infusion of t-butyl hydroperoxide and hydrogen peroxide separately, in the perfused liver of singhi catfish, resulted

Residual stress improvement for pipe weld by means of induction heating pre-flawed pipe

International Nuclear Information System (INIS)

Umemoto, T.; Yoshida, K.; Okamoto, A.

1980-01-01

The intergranular stress corrosion cracking (IGSCC) has been found in type 304 stainless steel piping of several BWR plants. It is already well known that IGSCC is most likely to occur when three essential factors, material sensitization, high tensile stress and corrosive environment, are present. If the welding residual stress is sufficiently high (200 to approximately 400 MPa) in the inside piping surface near the welded joint, then it may be one of the biggest contributors to IGSCC. If the residual stress is reduced or reversed by some way, the IGSCC will be effectively mitigated. In this paper a method to improve the residual stress named IHSI (Induction Heating Stress Improvement) is explained. IHSI aims to improve the condition of residual stress in the inside pipe surface using the thermal stress induced by the temperature difference in pipe wall, that is produced when the pipe is heated from the outside surface by an induction heating coil and cooled on the inside surface by water simultaneously. This method becomes more attractive when it can be successfully applied to in-service piping which might have some pre-flaw. In order to verify the validity of IHSI for such piping, some experiments and calculations using finite element method were conducted. These results are mainly discussed in this paper from the view-points of residual stress, flaw behaviour during IHSI and material deterioration. (author)

The SAT Protein of Porcine Parvovirus Accelerates Viral Spreading through Induction of Irreversible Endoplasmic Reticulum Stress.

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Mészáros, István; Tóth, Renáta; Olasz, Ferenc; Tijssen, Peter; Zádori, Zoltán

2017-08-15

The SAT protein (SATp) of porcine parvovirus (PPV) accumulates in the endoplasmic reticulum (ER), and SAT deletion induces the slow-spreading phenotype. The in vitro comparison of the wild-type Kresse strain and its SAT knockout (SAT - ) mutant revealed that prolonged cell integrity and late viral release are responsible for the slower spreading of the SAT - virus. During PPV infection, regardless of the presence or absence of SATp, the expression of downstream ER stress response proteins (Xbp1 and CHOP) was induced. However, in the absence of SATp, significant differences in the quantity and the localization of CHOP were detected, suggesting a role of SATp in the induction of irreversible ER stress in infected cells. The involvement of the induction of irreversible ER stress in porcine testis (PT) cell necrosis and viral egress was confirmed by treatment of infected cells by ER stress-inducing chemicals (MG132, dithiothreitol, and thapsigargin), which accelerated the egress and spreading of both the wild-type and the SAT - viruses. UV stress induction had no beneficial effect on PPV infection, underscoring the specificity of ER stress pathways in the process. However, induction of CHOP and its nuclear translocation cannot alone be responsible for the biological effect of SAT, since nuclear CHOP could not complement the lack of SAT in a coexpression experiment. IMPORTANCE SATp is encoded by an alternative open reading frame of the PPV genome. Earlier we showed that SATp of the attenuated PPV NADL-2 strain accumulates in the ER and accelerates virus release and spreading. Our present work revealed that slow spreading is a general feature of SAT - PPVs and is the consequence of prolonged cell integrity. PPV infection induced ER stress in infected cells regardless of the presence of SATp, as demonstrated by the morphological changes of the ER and expression of the stress response proteins Xbp1 and CHOP. However, the presence of SATp made the ER stress more severe and

Gene-based Association Approach Identify Genes Across Stress Traits in Fruit Flies

DEFF Research Database (Denmark)

Rohde, Palle Duun; Edwards, Stefan McKinnon; Sarup, Pernille Merete

Identification of genes explaining variation in quantitative traits or genetic risk factors of human diseases requires both good phenotypic- and genotypic data, but also efficient statistical methods. Genome-wide association studies may reveal association between phenotypic variation and variation...... approach grouping variants accordingly to gene position, thus lowering the number of statistical tests performed and increasing the probability of identifying genes with small to moderate effects. Using this approach we identify numerous genes associated with different types of stresses in Drosophila...... melanogaster, but also identify common genes that affects the stress traits....

Induction of stress- and immune-associated genes in the Indian meal moth Plodia interpunctella against envenomation by the ectoparasitoid Bracon hebetor.

Science.gov (United States)

Shafeeq, Tahir; UlAbdin, Zain; Lee, Kyeong-Yeoll

2017-10-01

Envenomation is an important process in parasitism by parasitic wasps; it suppresses the immune and development of host insects. However, the molecular mechanisms of host responses to envenomation are not yet clear. This study aimed to determine the transcription-level responses of the Indian meal moth Plodia interpunctella against envenomation of the ectoparasitoid Bracon hebetor. Quantitative real-time reverse-transcription PCR was used to determine the transcriptional changes of 13 selected genes, which are associated with development, metabolism, stress, or immunity, in the feeding and wandering fifth instar larvae over a 4-day period after envenomation. The effects of envenomation on the feeding-stage larvae were compared with those of starvation in the transcriptional levels of the 13 genes. Most selected genes were altered in their expression by either envenomation or starvation. In particular, a heat shock protein, hsp70, was highly upregulated in envenomated larvae in both the feeding and wandering stages as well as in starved larvae. Further, some genes were upregulated by envenomation in a stage-specific manner. For example, hsp25 was upregulated after envenomation in the feeding larvae, but hsp90 and an immune-associated gene, hemolin, were upregulated in the wandering larvae. However, both envenomation and starvation resulted in the downregulation of genes associated with development and metabolism. Taken together, P. interpunctella upregulated stress- and immune-responsive genes, but downregulated genes associated with development and metabolism after envenomation. This study provides important information for understanding the molecular mechanisms of host responses to parasitism. © 2017 Wiley Periodicals, Inc.

Differential Involvement of β-Glucosidases from Hypocrea jecorina in Rapid Induction of Cellulase Genes by Cellulose and Cellobiose

Science.gov (United States)

Zhou, Qingxin; Xu, Jintao; Kou, Yanbo; Lv, Xinxing; Zhang, Xi; Zhao, Guolei; Zhang, Weixin; Chen, Guanjun

2012-01-01

Appropriate perception of cellulose outside the cell by transforming it into an intracellular signal ensures the rapid production of cellulases by cellulolytic Hypocrea jecorina. The major extracellular β-glucosidase BglI (CEL3a) has been shown to contribute to the efficient induction of cellulase genes. Multiple β-glucosidases belonging to glycosyl hydrolase (GH) family 3 and 1, however, exist in H. jecorina. Here we demonstrated that CEL1b, like CEL1a, was an intracellular β-glucosidase displaying in vitro transglycosylation activity. We then found evidence that these two major intracellular β-glucosidases were involved in the rapid induction of cellulase genes by insoluble cellulose. Deletion of cel1a and cel1b significantly compromised the efficient gene expression of the major cellulase gene, cbh1. Simultaneous absence of BglI, CEL1a, and CEL1b caused the induction of the cellulase gene by cellulose to further deteriorate. The induction defect, however, was not observed with cellobiose. The absence of the three β-glucosidases, rather, facilitated the induced synthesis of cellulase on cellobiose. Furthermore, addition of cellobiose restored the productive induction on cellulose in the deletion strains. The results indicate that the three β-glucosidases may not participate in transforming cellobiose beyond hydrolysis to provoke cellulase formation in H. jecorina. They may otherwise contribute to the accumulation of cellobiose from cellulose as inducing signals. PMID:23002106

The dual role of cyclin C connects stress regulated gene expression to mitochondrial dynamics

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Randy Strich

2014-09-01

Full Text Available Following exposure to cytotoxic agents, cellular damage is first recognized by a variety of sensor mechanisms. Thenceforth, the damage signal is transduced to the nucleus to install the correct gene expression program including the induction of genes whose products either detoxify destructive compounds or repair the damage they cause. Next, the stress signal is disseminated throughout the cell to effect the appropriate changes at organelles including the mitochondria. The mitochondria represent an important signaling platform for the stress response. An initial stress response of the mitochondria is extensive fragmentation. If the damage is prodigious, the mitochondria fragment (fission and lose their outer membrane integrity leading to the release of pro-apoptotic factors necessary for programmed cell death (PCD execution. As this complex biological process contains many moving parts, it must be exquisitely coordinated as the ultimate decision is life or death. The conserved C-type cyclin plays an important role in executing this molecular Rubicon by coupling changes in gene expression to mitochondrial fission and PCD. Cyclin C, along with its cyclin dependent kinase partner Cdk8, associates with the RNA polymerase holoenzyme to regulate transcription. In particular, cyclin C-Cdk8 repress many stress responsive genes. To relieve this repression, cyclin C is destroyed in cells exposed to pro-oxidants and other stressors. However, prior to its destruction, cyclin C, but not Cdk8, is released from its nuclear anchor (Med13, translocates from the nucleus to the cytoplasm where it interacts with the fission machinery and is both necessary and sufficient to induce extensive mitochondria fragmentation. Furthermore, cytoplasmic cyclin C promotes PCD indicating that it mediates both mitochondrial fission and cell death pathways. This review will summarize the role cyclin C plays in regulating stress-responsive transcription. In addition, we will detail

Characterization of human adipose-derived stem cells and expression of chondrogenic genes during induction of cartilage differentiation.

Science.gov (United States)

Hamid, Adila A; Idrus, Ruszymah Bt Hj; Saim, Aminuddin Bin; Sathappan, Somasumdaram; Chua, Kien-Hui

2012-01-01

Understanding the changes in chondrogenic gene expression that are involved in the differentiation of human adipose-derived stem cells to chondrogenic cells is important prior to using this approach for cartilage repair. The aims of the study were to characterize human adipose-derived stem cells and to examine chondrogenic gene expression after one, two, and three weeks of induction. Human adipose-derived stem cells at passage 4 were evaluated by flow cytometry to examine the expression of surface markers. These adipose-derived stem cells were tested for adipogenic and osteogenic differentiation capacity. Ribonucleic acid was extracted from the cells for quantitative polymerase chain reaction analysis to determine the expression levels of chondrogenic genes after chondrogenic induction. Human adipose-derived stem cells were strongly positive for the mesenchymal markers CD90, CD73, CD44, CD9, and histocompatibility antigen and successfully differentiated into adipogenic and osteogenic lineages. The human adipose-derived stem cells aggregated and formed a dense matrix after chondrogenic induction. The expression of chondrogenic genes (collagen type II, aggrecan core protein, collagen type XI, COMP, and ELASTIN) was significantly higher after the first week of induction. However, a significantly elevated expression of collagen type X was observed after three weeks of chondrogenic induction. Human adipose-derived stem cells retain stem cell characteristics after expansion in culture to passage 4 and serve as a feasible source of cells for cartilage regeneration. Chondrogenesis in human adipose-derived stem cells was most prominent after one week of chondrogenic induction.

Characterization of human adipose-derived stem cells and expression of chondrogenic genes during induction of cartilage differentiation

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Adila A Hamid

2012-01-01

Full Text Available OBJECTIVES: Understanding the changes in chondrogenic gene expression that are involved in the differentiation of human adipose-derived stem cells to chondrogenic cells is important prior to using this approach for cartilage repair. The aims of the study were to characterize human adipose-derived stem cells and to examine chondrogenic gene expression after one, two, and three weeks of induction. MATERIALS AND METHODS: Human adipose-derived stem cells at passage 4 were evaluated by flow cytometry to examine the expression of surface markers. These adipose-derived stem cells were tested for adipogenic and osteogenic differentiation capacity. Ribonucleic acid was extracted from the cells for quantitative polymerase chain reaction analysis to determine the expression levels of chondrogenic genes after chondrogenic induction. RESULTS: Human adipose-derived stem cells were strongly positive for the mesenchymal markers CD90, CD73, CD44, CD9, and histocompatibility antigen and successfully differentiated into adipogenic and osteogenic lineages. The human adipose-derived stem cells aggregated and formed a dense matrix after chondrogenic induction. The expression of chondrogenic genes (collagen type II, aggrecan core protein, collagen type XI, COMP, and ELASTIN was significantly higher after the first week of induction. However, a significantly elevated expression of collagen type X was observed after three weeks of chondrogenic induction. CONCLUSION: Human adipose-derived stem cells retain stem cell characteristics after expansion in culture to passage 4 and serve as a feasible source of cells for cartilage regeneration. Chondrogenesis in human adiposederived stem cells was most prominent after one week of chondrogenic induction.

Induction of time-dependent oxidative stress and related transcriptional effects of perfluorododecanoic acid in zebrafish liver

Energy Technology Data Exchange (ETDEWEB)

Liu Yang [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Beijing 100101 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100080 (China); Wang Jianshe; Wei Yanhong; Zhang Hongxia; Xu Muqi [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Beijing 100101 (China); Dai Jiayin [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Beijing 100101 (China)], E-mail: daijy@ioz.ac.cn

2008-09-29

The effects of acute perfluorododecanoic acid (PFDoA) exposure on the induction of oxidative stress and alteration of mitochondrial gene expression were studied in the livers of female zebrafish (Danio rerio). Female zebrafish were exposed to PFDoA via a single intraperitoneal injection (0, 20, 40, or 80 {mu}g PFDoA/g body weight) and were then sacrificed 48 h, 96 h, or seven days post-PFDoA administration. PFDoA-treated fish exhibited histopathological liver damage, including swollen hepatocytes, vacuolar degeneration, and nuclei pycnosis. Glutathione (GSH) content and catalase (CAT) activity decreased significantly at 48 h post-injection while superoxide dismutase (SOD) activity was initially decreased at 48 h post-injection but was then elevated by seven days post-injection. The activity of glutathione peroxidase (GPx) increased at 48 h and seven days compared to control fish, although the increased level at seven days post-injection was decreased compared to the level at 48 h post-injection. Lipid peroxidation levels were increased at seven days post-injection, while no apparent induction was observed at 48 h or 96 h post-injection. The mRNA expression of medium-chain fatty acid dehydrogenase (MCAD) was induced, while the transcriptional expression of liver fatty acid binding protein (L-FABP), peroxisome proliferating activating receptor {alpha} (PPAR{alpha}), carnitine palmitoyl-transferase I (CPT-I), uncoupling protein 2 (UCP-2), and Bcl-2 were significantly inhibited. Furthermore, the transcriptional expression of peroxisomal fatty acyl-CoA oxidase (ACOX), very long-chain acyl-CoA dehydrogenase (VLCAD), long-chain acyl-CoA dehydrogenase (LCAD) did not exhibit significant changes following PFDoA treatment. No significant changes were noted in the transcriptional expression of genes involved in mitochondrial respiratory chain and ATP synthesis, including cytochrome c oxidase subunit I (COXI), NADH dehydrogenase subunit I (NDI), and ATP synthase F0 subunit 6

Induction of time-dependent oxidative stress and related transcriptional effects of perfluorododecanoic acid in zebrafish liver

International Nuclear Information System (INIS)

Liu Yang; Wang Jianshe; Wei Yanhong; Zhang Hongxia; Xu Muqi; Dai Jiayin

2008-01-01

The effects of acute perfluorododecanoic acid (PFDoA) exposure on the induction of oxidative stress and alteration of mitochondrial gene expression were studied in the livers of female zebrafish (Danio rerio). Female zebrafish were exposed to PFDoA via a single intraperitoneal injection (0, 20, 40, or 80 μg PFDoA/g body weight) and were then sacrificed 48 h, 96 h, or seven days post-PFDoA administration. PFDoA-treated fish exhibited histopathological liver damage, including swollen hepatocytes, vacuolar degeneration, and nuclei pycnosis. Glutathione (GSH) content and catalase (CAT) activity decreased significantly at 48 h post-injection while superoxide dismutase (SOD) activity was initially decreased at 48 h post-injection but was then elevated by seven days post-injection. The activity of glutathione peroxidase (GPx) increased at 48 h and seven days compared to control fish, although the increased level at seven days post-injection was decreased compared to the level at 48 h post-injection. Lipid peroxidation levels were increased at seven days post-injection, while no apparent induction was observed at 48 h or 96 h post-injection. The mRNA expression of medium-chain fatty acid dehydrogenase (MCAD) was induced, while the transcriptional expression of liver fatty acid binding protein (L-FABP), peroxisome proliferating activating receptor α (PPARα), carnitine palmitoyl-transferase I (CPT-I), uncoupling protein 2 (UCP-2), and Bcl-2 were significantly inhibited. Furthermore, the transcriptional expression of peroxisomal fatty acyl-CoA oxidase (ACOX), very long-chain acyl-CoA dehydrogenase (VLCAD), long-chain acyl-CoA dehydrogenase (LCAD) did not exhibit significant changes following PFDoA treatment. No significant changes were noted in the transcriptional expression of genes involved in mitochondrial respiratory chain and ATP synthesis, including cytochrome c oxidase subunit I (COXI), NADH dehydrogenase subunit I (NDI), and ATP synthase F0 subunit 6 (ATPo6). These

The cis-regulatory element CCACGTGG is involved in ABA and water-stress responses of the maize gene rab28.

Science.gov (United States)

Pla, M; Vilardell, J; Guiltinan, M J; Marcotte, W R; Niogret, M F; Quatrano, R S; Pagès, M

1993-01-01

The maize gene rab28 has been identified as ABA-inducible in embryos and vegetative tissues. It is also induced by water stress in young leaves. The proximal promoter region contains the conserved cis-acting element CCACGTGG (ABRE) reported for ABA induction in other plant genes. Transient expression assays in rice protoplasts indicate that a 134 bp fragment (-194 to -60 containing the ABRE) fused to a truncated cauliflower mosaic virus promoter (35S) is sufficient to confer ABA-responsiveness upon the GUS reporter gene. Gel retardation experiments indicate that nuclear proteins from tissues in which the rab28 gene is expressed can interact specifically with this 134 bp DNA fragment. Nuclear protein extracts from embryo and water-stressed leaves generate specific complexes of different electrophoretic mobility which are stable in the presence of detergent and high salt. However, by DMS footprinting the same guanine-specific contacts with the ABRE in both the embryo and leaf binding activities were detected. These results indicate that the rab28 promoter sequence CCACGTGG is a functional ABA-responsive element, and suggest that distinct regulatory factors with apparent similar affinity for the ABRE sequence may be involved in the hormone action during embryo development and in vegetative tissues subjected to osmotic stress.

Development of technique to apply induction heating stress improvement to recirculation inlet nozzle

International Nuclear Information System (INIS)

Chiba, Kunihiko; Nihei, Kenichi; Ootaka, Minoru

2009-01-01

Stress corrosion cracking (SCC) have been found in the primary loop recirculation (PLR) systems of boiling water reactors (BWR). Residual stress in welding heat-affected zone is one of the factors of SCC, and the residual stress improvement is one of the most effective methods to prevent SCC. Induction heating stress improvement (IHSI) is one of the techniques to improve reduce residual stress. However, it is difficult to apply IHSI to the place such as the recirculation inlet nozzle where the flow stagnates. In this present study, the technique to apply IHSI to the recirculation inlet nozzle was developed using water jet which blowed into the crevice between the nozzle safe end and the thermal sleeve. (author)

Exposure of Lactating Dairy Cows to Acute Pre-Ovulatory Heat Stress Affects Granulosa Cell-Specific Gene Expression Profiles in Dominant Follicles

Science.gov (United States)

Vanselow, Jens; Vernunft, Andreas; Koczan, Dirk; Spitschak, Marion; Kuhla, Björn

2016-01-01

High environmental temperatures induce detrimental effects on various reproductive processes in cattle. According to the predicted global warming the number of days with unfavorable ambient temperatures will further increase. The objective of this study was to investigate effects of acute heat stress during the late pre-ovulatory phase on morphological, physiological and molecular parameters of dominant follicles in cycling cows during lactation. Eight German Holstein cows in established lactation were exposed to heat stress (28°C) or thermoneutral conditions (15°C) with pair-feeding for four days. After hormonal heat induction growth of the respective dominant follicles was monitored by ultrasonography for two days, then an ovulatory GnRH dose was given and follicular steroid hormones and granulosa cell-specific gene expression profiles were determined 23 hrs thereafter. The data showed that the pre-ovulatory growth of dominant follicles and the estradiol, but not the progesterone concentrations tended to be slightly affected. mRNA microarray and hierarchical cluster analysis revealed distinct expression profiles in granulosa cells derived from heat stressed compared to pair-fed animals. Among the 255 affected genes heatstress-, stress- or apoptosis associated genes were not present. But instead, we found up-regulation of genes essentially involved in G-protein coupled signaling pathways, extracellular matrix composition, and several members of the solute carrier family as well as up-regulation of FST encoding follistatin. In summary, the data of the present study show that acute pre-ovulatory heat stress can specifically alter gene expression profiles in granulosa cells, however without inducing stress related genes and pathways and suggestively can impair follicular growth due to affecting the activin-inhibin-follistatin system. PMID:27532452

Toxicological responses of environmental mixtures: Environmental metal mixtures display synergistic induction of metal-responsive and oxidative stress genes in placental cells

Energy Technology Data Exchange (ETDEWEB)

Adebambo, Oluwadamilare A. [Department of Biological Sciences, North Carolina State University (United States); Ray, Paul D. [Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill (United States); Shea, Damian [Department of Biological Sciences, North Carolina State University (United States); Fry, Rebecca C., E-mail: rfry@unc.edu [Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill (United States)

2015-12-15

Exposure to elevated levels of the toxic metals inorganic arsenic (iAs) and cadmium (Cd) represents a major global health problem. These metals often occur as mixtures in the environment, creating the potential for interactive or synergistic biological effects different from those observed in single exposure conditions. In the present study, environmental mixtures collected from two waste sites in China and comparable mixtures prepared in the laboratory were tested for toxicogenomic response in placental JEG-3 cells. These cells serve as a model for evaluating cellular responses to exposures during pregnancy. One of the mixtures was predominated by iAs and one by Cd. Six gene biomarkers were measured in order to evaluate the effects from the metal mixtures using dose and time-course experiments including: heme oxygenase 1 (HO-1) and metallothionein isoforms (MT1A, MT1F and MT1G) previously shown to be preferentially induced by exposure to either iAs or Cd, and metal transporter genes aquaporin-9 (AQP9) and ATPase, Cu{sup 2+} transporting, beta polypeptide (ATP7B). There was a significant increase in the mRNA expression levels of ATP7B, HO-1, MT1A, MT1F, and MT1G in mixture-treated cells compared to the iAs or Cd only-treated cells. Notably, the genomic responses were observed at concentrations significantly lower than levels found at the environmental collection sites. These data demonstrate that metal mixtures increase the expression of gene biomarkers in placental JEG-3 cells in a synergistic manner. Taken together, the data suggest that toxic metals that co-occur may induce detrimental health effects that are currently underestimated when analyzed as single metals. - Highlights: • Toxicogenomic responses of environmental metal mixtures assessed • Induction of ATP7B, HO-1, MT1A, MT1F and MT1G by metal mixtures observed in placental cells • Higher gene induction in response to metal mixtures versus single metal treatments.

Toxicological responses of environmental mixtures: Environmental metal mixtures display synergistic induction of metal-responsive and oxidative stress genes in placental cells

International Nuclear Information System (INIS)

Adebambo, Oluwadamilare A.; Ray, Paul D.; Shea, Damian; Fry, Rebecca C.

2015-01-01

Exposure to elevated levels of the toxic metals inorganic arsenic (iAs) and cadmium (Cd) represents a major global health problem. These metals often occur as mixtures in the environment, creating the potential for interactive or synergistic biological effects different from those observed in single exposure conditions. In the present study, environmental mixtures collected from two waste sites in China and comparable mixtures prepared in the laboratory were tested for toxicogenomic response in placental JEG-3 cells. These cells serve as a model for evaluating cellular responses to exposures during pregnancy. One of the mixtures was predominated by iAs and one by Cd. Six gene biomarkers were measured in order to evaluate the effects from the metal mixtures using dose and time-course experiments including: heme oxygenase 1 (HO-1) and metallothionein isoforms (MT1A, MT1F and MT1G) previously shown to be preferentially induced by exposure to either iAs or Cd, and metal transporter genes aquaporin-9 (AQP9) and ATPase, Cu 2+ transporting, beta polypeptide (ATP7B). There was a significant increase in the mRNA expression levels of ATP7B, HO-1, MT1A, MT1F, and MT1G in mixture-treated cells compared to the iAs or Cd only-treated cells. Notably, the genomic responses were observed at concentrations significantly lower than levels found at the environmental collection sites. These data demonstrate that metal mixtures increase the expression of gene biomarkers in placental JEG-3 cells in a synergistic manner. Taken together, the data suggest that toxic metals that co-occur may induce detrimental health effects that are currently underestimated when analyzed as single metals. - Highlights: • Toxicogenomic responses of environmental metal mixtures assessed • Induction of ATP7B, HO-1, MT1A, MT1F and MT1G by metal mixtures observed in placental cells • Higher gene induction in response to metal mixtures versus single metal treatments

Genes, stress, and depression.

Science.gov (United States)

Wurtman, Richard J

2005-05-01

A relationship between genetic makeup and susceptibility to major depressive disorder (MDD) has long been suspected on the basis of family and twin studies. A metaanalysis of reports on the basis of twin studies has estimated MDD's degree of heritability to be 0.33 (confidence interval, 0.26-0.39). Among families exhibiting an increased prevalence of MDD, risk of developing the illness was enhanced in members exposed to a highly stressful environment. Aberrant genes can predispose to depression in a number of ways, for example, by diminishing production of growth factors that act during brain development. An aberrant gene could also increase or decrease a neurotransmitter's release into synapses, its actions, or its duration of activity. The gene products of greatest interest at present are those involved in the synthesis and actions of serotonin; among them, the serotonin-uptake protein localized within the terminals and dendrites of serotonin-releasing neurons. It has been found that the Vmax of platelet serotonin uptake is low in some patients with MDD; also, Vmax is highly correlated in twins. Antidepressant drugs such as the selective serotonin reuptake inhibitors act on this uptake protein. The specific genetic locus causing serotonin uptake to be lower in some patients with major depression involves a polymorphic region (5-HTTLPR) in the promoter region of the gene for the uptake protein. The gene itself exists as several alleles, the short "S" allele and the long "L" allele. The S variant is associated with less, and the L variant with more, of the uptake protein. The effect of stressful life events on depressive symptoms in young adults was found to be significantly stronger among SS or SL subjects than among LL subjects. Neuroimaging studies showed that people with the SS or SL alleles exhibited a greater activation of the amygdala in response to fearful stimuli than those with LL. It has been reported recently that mutations in the gene that controls

Role of arachidonic acid metabolism in transcriptional induction of tumor necrosis factor gene expression by phorbol ester

Energy Technology Data Exchange (ETDEWEB)

Horiguchi, J.; Spriggs, D.; Imamura, K.; Stone, R.; Luebbers, R.; Kufe, D.

1989-01-01

The treatment of human HL-60 promyelocytic leukemia cells with 12-0 tetradecanoylphorbol-13-acetate (TPA) is associated with induction of tumor necrosis factor (TNF) transcripts. The study reported here has examined TPA-induced signaling mechanisms responsible for the regulation of TNF gene expression in these cells. Run-on assays demonstrated that TPA increases TNS mRNA levels by transcriptional activation of this gene. The induction of TNF transcripts by TPA was inhibited by the isoquinolinesulfonamide derivative H7 but not by HA1004, suggesting that this effect of TPA is mediated by activation of protein kinase C. TPA treatment also resulted in increased arachidonic acid release. Moreover, inhibitors of phospholipase, A/sub 2/ blocked both the increase in arachidonic acid release and the induction of TNF transcripts. These findings suggest that TPA induces TNF gene expression through the formation of arachidonic acid metabolites. Although indomethacin had no detectable effect on this induction of TNF transcripts, ketoconazole, an inhibitor of 5-lipoxygenase, blocked TPA-induced increases in TNF mRNA levels. Moreover, TNF mRNA levels were increased by the 5-lipoxygenase metabolite leukotriene B/sub 4/. In contrast, the cyclooxygenase metabolite prostaglandin E/sub 2/ inhibited the induction of TNF transcripts by TPA. Taken together, these results suggest that TPA induces TNF gene expression through the arachidonic acid cascade and that the level of TNF transcripts is regulated by metabolites of the pathway, leukotriene B/sub 4/ and prostaglandin E/sub 2/.

Globular adiponectin protects rat hepatocytes against acetaminophen-induced cell death via modulation of the inflammasome activation and ER stress: Critical role of autophagy induction.

Science.gov (United States)

Kim, Eun Hye; Park, Pil-Hoon

2018-05-24

Acetaminophen (APAP) overdose treatment causes severe liver injury. Adiponectin, a hormone predominantly produced by adipose tissue, exhibits protective effects against APAP-induced hepatotoxicity. However, the underlying mechanisms are not clearly understood. In the present study, we examined the protective effect of globular adiponectin (gAcrp) on APAP-induced hepatocyte death and its underlying mechanisms. We found that APAP (2 mM)-induced hepatocyte death was prevented by inhibition of the inflammasome. In addition, treatment with gAcrp (0.5 and 1 μg/ml) inhibited APAP-induced activation of the inflammasome, judged by suppression of interleukin-1β maturation, caspase-1 activation, and apoptosis-associated speck-like protein (ASC) speck formation, suggesting that protective effects of gAcrp against APAP-induced hepatocyte death is mediated via modulation of the inflammasome. APAP also induced ER stress and treatment with tauroursodeoxycholic acid (TUDCA), an ER chaperone and inhibitor of ER stress, abolished APAP-induced inflammasomes activation, implying that ER stress acts as signaling event leading to the inflammasome activation in hepatocytes stimulated with APAP. Moreover, gAcrp significantly suppressed APAP-induced expression of ER stress marker genes. Finally, the modulatory effects of gAcrp on ER stress and inflammasomes activation were abrogated by treatment with autophagy inhibitors, while an autophagy inducer (rapamycin) suppressed APAP-elicited ER stress, demonstrating that autophagy induction plays a crucial role in the suppression of APAP-induced inflammasome activation and ER stress by gAcrp. Taken together, these results indicate that gAcrp protects hepatocytes against APAP-induced cell death by modulating ER stress and the inflammasome activation, at least in part, via autophagy induction. Copyright © 2018. Published by Elsevier Inc.

Tumoral Environment Triggers Transcript Anomalies in Established Tumors: Induction of Altered Gene Expression and of Aberrant, Truncated and B2 Repeat-Containing Gene Transcripts

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Pieter Rottiers

1999-12-01

Full Text Available In addition to eugenetic changes, cancerous cells exhibit extensive modifications in the expression levels of a variety of genes. The phenotypic switch observed after inoculation of T lymphoma cells into syngenic mice illustrates the active participation of tumoral environment in the induction of an aberrant gene expression pattern. To further substantiate this contribution, we performed polymerase chain reaction (PCR-based subtraction suppression hybridization (SSH to identify genes that are differentially expressed in tumor-derived EL4/13.3 cells compared to the same cells isolated from cultures. Besides a number of unknown genes, the subtracted library contained several known genes that have been reported to be expressed at increased levels in tumors and/or to contribute to carcinogenesis. Apart from clones representing translated transcripts, the subtracted library also contained a high number of clones representing B2 repeat elements, viz. short interspersed repetitive elements that are transcribed by RNA polymerase III. Northern blotting confirmed the induction of B2 transcripts in tumor tissue and also revealed induction of chimeric, B2 repeat-containing mRNA. The appearance of chimeric transcripts was accompanied by aberrant, shorter-than-full-length transcripts, specifically from upregulated genes. Accordingly, in addition to altered gene expression, tumoral environmental triggers constitute a potent mechanism to create an epigenetic diversity in cancers by inducing extensive transcript anomalies.

Fast-acting and nearly gratuitous induction of gene expression and protein depletion in Saccharomyces cerevisiae

Science.gov (United States)

McIsaac, R. Scott; Silverman, Sanford J.; McClean, Megan N.; Gibney, Patrick A.; Macinskas, Joanna; Hickman, Mark J.; Petti, Allegra A.; Botstein, David

2011-01-01

We describe the development and characterization of a system that allows the rapid and specific induction of individual genes in the yeast Saccharomyces cerevisiae without changes in nutrients or temperature. The system is based on the chimeric transcriptional activator Gal4dbd.ER.VP16 (GEV). Upon addition of the hormone β-estradiol, cytoplasmic GEV localizes to the nucleus and binds to promoters containing Gal4p consensus binding sequences to activate transcription. With galactokinase Gal1p and transcriptional activator Gal4p absent, the system is fast-acting, resulting in readily detectable transcription within 5 min after addition of the inducer. β-Estradiol is nearly a gratuitous inducer, as indicated by genome-wide profiling that shows unintended induction (by GEV) of only a few dozen genes. Response to inducer is graded: intermediate concentrations of inducer result in production of intermediate levels of product protein in all cells. We present data illustrating several applications of this system, including a modification of the regulated degron method, which allows rapid and specific degradation of a specific protein upon addition of β-estradiol. These gene induction and protein degradation systems provide important tools for studying the dynamics and functional relationships of genes and their respective regulatory networks. PMID:21965290

Halophytes: Potential Resources for Salt Stress Tolerance Genes and Promoters.

Science.gov (United States)

Mishra, Avinash; Tanna, Bhakti

2017-01-01

Halophytes have demonstrated their capability to thrive under extremely saline conditions and thus considered as one of the best germplasm for saline agriculture. Salinity is a worldwide problem, and the salt-affected areas are increasing day-by-day because of scanty rainfall, poor irrigation system, salt ingression, water contamination, and other environmental factors. The salinity stress tolerance mechanism is a very complex phenomenon, and some pathways are coordinately linked for imparting salinity tolerance. Though a number of salt responsive genes have been reported from the halophytes, there is always a quest for promising stress-responsive genes that can modulate plant physiology according to the salt stress. Halophytes such as Aeluropus, Mesembryanthemum, Suaeda, Atriplex, Thellungiella, Cakile , and Salicornia serve as a potential candidate for the salt-responsive genes and promoters. Several known genes like antiporters ( NHX, SOS, HKT, VTPase ), ion channels (Cl - , Ca 2+ , aquaporins), antioxidant encoding genes ( APX, CAT, GST, BADH, SOD ) and some novel genes such as USP, SDR1, SRP etc. were isolated from halophytes and explored for developing stress tolerance in the crop plants (glycophytes). It is evidenced that stress triggers salt sensors that lead to the activation of stress tolerance mechanisms which involve multiple signaling proteins, up- or down-regulation of several genes, and finally the distinctive or collective effects of stress-responsive genes. In this review, halophytes are discussed as an excellent platform for salt responsive genes which can be utilized for developing salinity tolerance in crop plants through genetic engineering.

Expression induction of P450 genes by imidacloprid in Nilaparvata lugens: A genome-scale analysis.

Science.gov (United States)

Zhang, Jianhua; Zhang, Yixi; Wang, Yunchao; Yang, Yuanxue; Cang, Xinzhu; Liu, Zewen

2016-09-01

The overexpression of P450 monooxygenase genes is a main mechanism for the resistance to imidacloprid, a representative neonicotinoid insecticide, in Nilaparvata lugens (brown planthopper, BPH). However, only two P450 genes (CYP6AY1 and CYP6ER1), among fifty-four P450 genes identified from BPH genome database, have been reported to play important roles in imidacloprid resistance until now. In this study, after the confirmation of important roles of P450s in imidacloprid resistance by the synergism analysis, the expression induction by imidacloprid was determined for all P450 genes. In the susceptible (Sus) strain, eight P450 genes in Clade4, eight in Clade3 and two in Clade2 were up-regulated by imidacloprid, among which three genes (CYP6CS1, CYP6CW1 and CYP6ER1, all in Clade3) were increased to above 4.0-fold and eight genes to above 2.0-fold. In contrast, no P450 genes were induced in Mito clade. Eight genes induced to above 2.0-fold were selected to determine their expression and induced levels in Huzhou population, in which piperonyl butoxide showed the biggest effects on imidacloprid toxicity among eight field populations. The expression levels of seven P450 genes were higher in Huzhou population than that in Sus strain, with the biggest differences for CYP6CS1 (9.8-fold), CYP6ER1 (7.7-fold) and CYP6AY1 (5.1-fold). The induction levels for all tested genes were bigger in Sus strain than that in Huzhou population except CYP425B1. Screening the induction of P450 genes by imidacloprid in the genome-scale will provide an overall view on the possible metabolic factors in the resistance to neonicotinoid insecticides. The further work, such as the functional study of recombinant proteins, will be performed to validate the roles of these P450s in imidacloprid resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

Residual stress state in an induction hardened steel bar determined by synchrotron- and neutron diffraction compared to results from lab-XRD

International Nuclear Information System (INIS)

Holmberg, Jonas; Steuwer, Axel; Stormvinter, Albin; Kristoffersen, Hans; Haakanen, Merja; Berglund, Johan

2016-01-01

Induction hardening is a relatively rapid heat treatment method to increase mechanical properties of steel components. However, results from FE-simulation of the induction hardening process show that a tensile stress peak will build up in the transition zone in order to balance the high compressive stresses close to the surface. This tensile stress peak is located in the transition zone between the hardened zone and the core material. The main objective with this investigation has been to non-destructively validate the residual stress state throughout an induction hardened component. Thereby, allowing to experimentally confirming the existence and magnitude of the tensile stress peak arising from rapid heat treatment. For this purpose a cylindrical steel bar of grade C45 was induction hardened and characterised regarding the microstructure, hardness, hardening depth and residual stresses. This investigation shows that a combined measurement with synchrotron/neutron diffraction is well suited to non-destructively measure the strains through the steel bar of a diameter of 20 mm and thereby making it possible to calculate the residual stress profile. The result verified the high compressive stresses at the surface which rapidly changes to tensile stresses in the transition zone resulting in a large tensile stress peak. Measured stresses by conventional lab-XRD showed however that at depths below 1.5 mm the stresses were lower compared to the synchrotron and neutron data. This is believed to be an effect of stress relaxation from the layer removal. The FE-simulation predicts the depth of the tensile stress peak well but exaggerates the magnitude compared to the measured results by synchrotron/neutron measurements. This is an important knowledge when designing the component and the heat treatment process since this tensile stress peak will have great impact on the mechanical properties of the final component.

Residual stress state in an induction hardened steel bar determined by synchrotron- and neutron diffraction compared to results from lab-XRD

Energy Technology Data Exchange (ETDEWEB)

Holmberg, Jonas, E-mail: jonas.holmberg@swerea.se [Swerea IVF AB, Argongatan 30, 431 22 Mölndal (Sweden); University West, 461 86 Trollhättan (Sweden); Steuwer, Axel [Nelson Mandela Metropolitan University, Gardham Avenue, 6031 Port Elizabeth (South Africa); Stormvinter, Albin; Kristoffersen, Hans [Swerea IVF AB, Argongatan 30, 431 22 Mölndal (Sweden); Haakanen, Merja [Stresstech OY, Tikkutehtaantie 1, 40 800 Vaajakoski (Finland); Berglund, Johan [Swerea IVF AB, Argongatan 30, 431 22 Mölndal (Sweden)

2016-06-14

Induction hardening is a relatively rapid heat treatment method to increase mechanical properties of steel components. However, results from FE-simulation of the induction hardening process show that a tensile stress peak will build up in the transition zone in order to balance the high compressive stresses close to the surface. This tensile stress peak is located in the transition zone between the hardened zone and the core material. The main objective with this investigation has been to non-destructively validate the residual stress state throughout an induction hardened component. Thereby, allowing to experimentally confirming the existence and magnitude of the tensile stress peak arising from rapid heat treatment. For this purpose a cylindrical steel bar of grade C45 was induction hardened and characterised regarding the microstructure, hardness, hardening depth and residual stresses. This investigation shows that a combined measurement with synchrotron/neutron diffraction is well suited to non-destructively measure the strains through the steel bar of a diameter of 20 mm and thereby making it possible to calculate the residual stress profile. The result verified the high compressive stresses at the surface which rapidly changes to tensile stresses in the transition zone resulting in a large tensile stress peak. Measured stresses by conventional lab-XRD showed however that at depths below 1.5 mm the stresses were lower compared to the synchrotron and neutron data. This is believed to be an effect of stress relaxation from the layer removal. The FE-simulation predicts the depth of the tensile stress peak well but exaggerates the magnitude compared to the measured results by synchrotron/neutron measurements. This is an important knowledge when designing the component and the heat treatment process since this tensile stress peak will have great impact on the mechanical properties of the final component.

Induction, by thymidylate stress, of genetic recombination as evidenced by deletion of a transferred genetic marker in mouse FM3A cells

International Nuclear Information System (INIS)

Ayusawa, D.; Koyama, H.; Shimizu, K.; Kaneda, S.; Takeishi, K.; Seno, T.

1986-01-01

Studies were made on the genetic consequences of methotrexate-directed thymidylate stress, focusing attention on a human thymidylate synthase gene that was introduced as a heterologous genetic marker into mouse thymidylate synthase-negative mutant cells. Thymidylate stress induced thymidylate synthase-negative segregants with concomitant loss of human thymidylate synthase activity with frequencies 1 to 2 orders of magnitude higher than the uninduced spontaneous level in some but not all transformant lines. Induction of the segregants was suppressed almost completely by cycloheximide and partially by caffeine. Thymidylate stress did not, however, induce mutations, as determined by measuring resistance to ouabain or 6-thioguanine. Thymidylate synthase-negative segregants were also induced by other means such as bromodeoxyuridine treatment and X-ray irradiation. In each of the synthase-negative segregants induced by thymidylate stress, a DNA segment including almost the whole coding region of the transferred human thymidylate synthase gene was deleted in a very specific manner, as shown by Southern blot analysis with a human Alu sequence and a human thymidylate synthase cDNA as probes. In the segregants that emerged spontaneously at low frequency, the entire transferred genetic marker was lost. In the segregants induced by X-ray irradiation, structural alterations of the genetic marker were random. These results show that thymidylate stress is a physiological factor that provokes the instability of this exogenously incorporated DNA in some specific manner and produces nonrandom genetic recombination in mammalian cells

Differential gene expression and mitotic cell analysis of the drought tolerant soybean (Glycine max L. Merrill Fabales, Fabaceae cultivar MG/BR46 (Conquista under two water deficit induction systems

Directory of Open Access Journals (Sweden)

Polyana K. Martins

2008-01-01

Full Text Available Drought cause serious yield losses in soybean (Glycine max, roots being the first plant organ to detect the water-stress signals triggering defense mechanisms. We used two drought induction systems to identify genes differentially expressed in the roots of the drought-tolerant soybean cultivar MG/BR46 (Conquista and characterize their expression levels during water deficit. Soybean plants grown in nutrient solution hydroponically and in sand-pots were submitted to water stress and gene expression analysis was conducted using the differential display (DD and real time polymerase chain reaction (PCR techniques. Three differentially expressed mRNA transcripts showed homology to the Antirrhinum majus basic helix-loop-helix transcription factor bHLH, the Arabidopsis thaliana phosphatidylinositol transfer protein PITP and the auxin-independent growth regulator 1 (axi 1. The hydroponic experiments showed that after 100 min outside the nutrient solution photosynthesis completely stopped, stomata closed and leaf temperature rose. Both stress induction treatments produced significant decrease in the mitotic indices of root cells. Axi 1, PITP and bHLH were not only differentially expressed during dehydration in the hydroponics experiments but also during induced drought in the pot experiments. Although, there were differences between the two sets of experiments in the time at which up or down regulation occurred, the expression pattern of all three transcripts was related. Similar gene expression and cytological analysis results occurred in both systems, suggesting that hydroponics could be used to simulate drought detection by roots growing in soil and thus facilitate rapid and easy root sampling.

Induction of fibroblast growth factor 21 does not require activation of the hepatic X-box binding protein 1 in mice

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Shantel Olivares

2017-12-01

Full Text Available Objective: Fibroblast growth factor 21 (FGF21, a key regulator of the metabolic response to fasting, is highly induced by endoplasmic reticulum (ER stress. The X-box binding protein 1 (Xbp1 is one of several ER stress proteins that has been shown to directly activate the FGF21 promoter. We aimed to determine whether hepatic Xbp1 is required for induction of hepatic FGF21 in vivo. Methods: Mice bearing a hepatocyte-specific deletion of Xbp1 (Xbp1LKO were subjected to fasting, pharmacologic ER stress, or a ketogenic diet, all potent stimuli of Fgf21 expression. Results: Hepatocyte-specific Xbp1 knockout mice demonstrated normal induction of FGF21 in response to fasting or pharmacologic ER stress and enhanced induction of FGF21 in response to a ketogenic diet. Consistent with preserved induction of FGF21, Xbp1LKO mice exhibited normal induction of FGF21 target genes and normal ketogenesis in response to fasting or a ketogenic diet. Conclusion: Hepatic Xbp1 is not required for induction of FGF21 under physiologic or pathophysiologic conditions in vivo. Keywords: Unfolded protein response, Endoplasmic reticulum stress, Fasting, Fatty acid oxidation, Ketogenic diet

Halophytes: Potential Resources for Salt Stress Tolerance Genes and Promoters

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Avinash Mishra

2017-05-01

Full Text Available Halophytes have demonstrated their capability to thrive under extremely saline conditions and thus considered as one of the best germplasm for saline agriculture. Salinity is a worldwide problem, and the salt-affected areas are increasing day-by-day because of scanty rainfall, poor irrigation system, salt ingression, water contamination, and other environmental factors. The salinity stress tolerance mechanism is a very complex phenomenon, and some pathways are coordinately linked for imparting salinity tolerance. Though a number of salt responsive genes have been reported from the halophytes, there is always a quest for promising stress-responsive genes that can modulate plant physiology according to the salt stress. Halophytes such as Aeluropus, Mesembryanthemum, Suaeda, Atriplex, Thellungiella, Cakile, and Salicornia serve as a potential candidate for the salt-responsive genes and promoters. Several known genes like antiporters (NHX, SOS, HKT, VTPase, ion channels (Cl−, Ca2+, aquaporins, antioxidant encoding genes (APX, CAT, GST, BADH, SOD and some novel genes such as USP, SDR1, SRP etc. were isolated from halophytes and explored for developing stress tolerance in the crop plants (glycophytes. It is evidenced that stress triggers salt sensors that lead to the activation of stress tolerance mechanisms which involve multiple signaling proteins, up- or down-regulation of several genes, and finally the distinctive or collective effects of stress-responsive genes. In this review, halophytes are discussed as an excellent platform for salt responsive genes which can be utilized for developing salinity tolerance in crop plants through genetic engineering.

Deciphering the role of the signal- and Sty1 kinase-dependent phosphorylation of the stress-responsive transcription factor Atf1 on gene activation.

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Salat-Canela, Clàudia; Paulo, Esther; Sánchez-Mir, Laura; Carmona, Mercè; Ayté, José; Oliva, Baldo; Hidalgo, Elena

2017-08-18

Adaptation to stress triggers the most dramatic shift in gene expression in fission yeast ( Schizosaccharomyces pombe ), and this response is driven by signaling via the MAPK Sty1. Upon activation, Sty1 accumulates in the nucleus and stimulates expression of hundreds of genes via the nuclear transcription factor Atf1, including expression of atf1 itself. However, the role of stress-induced, Sty1-mediated Atf1 phosphorylation in transcriptional activation is unclear. To this end, we expressed Atf1 phosphorylation mutants from a constitutive promoter to uncouple Atf1 activity from endogenous, stress-activated Atf1 expression. We found that cells expressing a nonphosphorylatable Atf1 variant are sensitive to oxidative stress because of impaired transcription of a subset of stress genes whose expression is also controlled by another transcription factor, Pap1. Furthermore, cells expressing a phospho-mimicking Atf1 mutant display enhanced stress resistance, and although expression of the Pap1-dependent genes still relied on stress induction, another subset of stress-responsive genes was constitutively expressed in these cells. We also observed that, in cells expressing the phospho-mimicking Atf1 mutant, the presence of Sty1 was completely dispensable, with all stress defects of Sty1-deficient cells being suppressed by expression of the Atf1 mutant. We further demonstrated that Sty1-mediated Atf1 phosphorylation does not stimulate binding of Atf1 to DNA but, rather, establishes a platform of interactions with the basal transcriptional machinery to facilitate transcription initiation. In summary, our results provide evidence that Atf1 phosphorylation by the MAPK Sty1 is required for oxidative stress responses in fission yeast cells by promoting transcription initiation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Stress tolerances of nullmutants of function-unknown genes encoding menadione stress-responsive proteins in Aspergillus nidulans.

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Leiter, Éva; Bálint, Mihály; Miskei, Márton; Orosz, Erzsébet; Szabó, Zsuzsa; Pócsi, István

2016-07-01

A group of menadione stress-responsive function-unkown genes of Aspergillus nidulans (Locus IDs ANID_03987.1, ANID_06058.1, ANID_10219.1, and ANID_10260.1) was deleted and phenotypically characterized. Importantly, comparative and phylogenetic analyses of the tested A. nidulans genes and their orthologs shed light only on the presence of a TANGO2 domain with NRDE protein motif in the translated ANID_06058.1 gene but did not reveal any recognizable protein-encoding domains in other protein sequences. The gene deletion strains were subjected to oxidative, osmotic, and metal ion stress and, surprisingly, only the ΔANID_10219.1 mutant showed an increased sensitivity to 0.12 mmol l(-1) menadione sodium bisulfite. The gene deletions affected the stress sensitivities (tolerances) irregularly, for example, some strains grew more slowly when exposed to various oxidants and/or osmotic stress generating agents, meanwhile the ΔANID_10260.1 mutant possessed a wild-type tolerance to all stressors tested. Our results are in line with earlier studies demonstrating that the deletions of stress-responsive genes do not confer necessarily any stress-sensitivity phenotypes, which can be attributed to compensatory mechanisms based on other elements of the stress response system with overlapping functions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stress amplifies sex differences in primate prefrontal profiles of gene expression.

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Lee, Alex G; Hagenauer, Megan; Absher, Devin; Morrison, Kathleen E; Bale, Tracy L; Myers, Richard M; Watson, Stanley J; Akil, Huda; Schatzberg, Alan F; Lyons, David M

2017-11-02

Stress is a recognized risk factor for mood and anxiety disorders that occur more often in women than men. Prefrontal brain regions mediate stress coping, cognitive control, and emotion. Here, we investigate sex differences and stress effects on prefrontal cortical profiles of gene expression in squirrel monkey adults. Dorsolateral, ventrolateral, and ventromedial prefrontal cortical regions from 18 females and 12 males were collected after stress or no-stress treatment conditions. Gene expression profiles were acquired using HumanHT-12v4.0 Expression BeadChip arrays adapted for squirrel monkeys. Extensive variation between prefrontal cortical regions was discerned in the expression of numerous autosomal and sex chromosome genes. Robust sex differences were also identified across prefrontal cortical regions in the expression of mostly autosomal genes. Genes with increased expression in females compared to males were overrepresented in mitogen-activated protein kinase and neurotrophin signaling pathways. Many fewer genes with increased expression in males compared to females were discerned, and no molecular pathways were identified. Effect sizes for sex differences were greater in stress compared to no-stress conditions for ventromedial and ventrolateral prefrontal cortical regions but not dorsolateral prefrontal cortex. Stress amplifies sex differences in gene expression profiles for prefrontal cortical regions involved in stress coping and emotion regulation. Results suggest molecular targets for new treatments of stress disorders in human mental health.

Modulation of Apoptosis Pathways by Oxidative Stress and Autophagy in β Cells

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Maorong Wang

2012-01-01

Full Text Available Human islets isolated for transplantation are exposed to multiple stresses including oxidative stress and hypoxia resulting in significant loss of functional β cell mass. In this study we examined the modulation of apoptosis pathway genes in islets exposed to hydrogen peroxide, peroxynitrite, hypoxia, and cytokines. We observed parallel induction of pro- and antiapoptotic pathways and identified several novel genes including BFAR, CARD8, BNIP3, and CIDE-A. As BNIP3 is an inducer of autophagy, we examined this pathway in MIN6 cells, a mouse beta cell line and in human islets. Culture of MIN6 cells under low serum conditions increased the levels of several proteins in autophagy pathway, including ATG4, Beclin 1, LAMP-2, and UVRAG. Amino acid deprivation led to induction of autophagy in human islets. Preconditioning of islets with inducers of autophagy protected them from hypoxia-induced apoptosis. However, induction of autophagy during hypoxia exacerbated apoptotic cell death. ER stress led to induction of autophagy and apoptosis in β cells. Overexpression of MnSOD, an enzyme that scavenges free radicals, resulted in protection of MIN6 cells from cytokine-induced apoptosis. Ceramide, a mediator of cytokine-induced injury, reduced the active phosphorylated form of Akt and downregulated the promoter activity of the antiapoptotic gene bcl-2. Furthermore, cytokine-stimulated JNK pathway downregulated the bcl-2 promoter activity which was reversed by preincubation with SP600125, a JNK inhibitor. Our findings suggest that β cell apoptosis by multiple stresses in islets isolated for transplantation is the result of orchestrated gene expression in apoptosis pathway.

Stress-induced activation of the immediate early gene Arc (activity-regulated cytoskeleton-associated protein) is restricted to telencephalic areas in the rat brain: relationship to c-fos mRNA.

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Ons, Sheila; Martí, Octavi; Armario, Antonio

2004-06-01

Arc is an effector immediate early gene whose expression is induced in situations of increased neuronal activity. However, there is no report on the influence of stress on Arc expression. Here, we compared the induction of both c-fos and Arc mRNAs in the brain of rats exposed to one of three different stressful situations: novel environment, forced swimming and immobilization. An absent or weak c-fos mRNA signal was observed in control rats, whereas those exposed to one of three stressors showed enhanced c-fos expression in a wide range of brain areas. Constitutive Arc expression was observed in some areas such as cortex, striatum, hippocampus, reticular thalamic nucleus and cerebellar cortex. In response to stressors, a strong induction of Arc was observed, but the pattern was different from that of c-fos. For instance, activation of Arc but not c-fos was observed in the nucleus accumbens after immobilization and in the hippocampus after novel environment. No Arc induction was observed in diencephalic and brainstem areas. The present data show that Arc has a neuroanatomically restricted pattern of induction in the brain after emotional stress. Telencephalic activation suggests that a more intense induction of synaptic plasticity is occurring in this area after exposure to emotional stressors.

A root specific induction of carotenoid biosynthesis contributes to ABA production upon salt stress in arabidopsis.

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M Águila Ruiz-Sola

Full Text Available Abscisic acid (ABA is a hormone that plays a vital role in mediating abiotic stress responses in plants. Salt exposure induces the synthesis of ABA through the cleavage of carotenoid precursors (xanthophylls, which are found at very low levels in roots. Here we show that de novo ABA biosynthesis in salt-treated Arabidopsis thaliana roots involves an organ-specific induction of the carotenoid biosynthetic pathway. Upregulation of the genes encoding phytoene synthase (PSY and other enzymes of the pathway producing ABA precursors was observed in roots but not in shoots after salt exposure. A pharmacological block of the carotenoid pathway substantially reduced ABA levels in stressed roots, confirming that an increase in carotenoid accumulation contributes to fuel hormone production after salt exposure. Treatment with exogenous ABA was also found to upregulate PSY expression only in roots, suggesting an organ-specific feedback regulation of the carotenoid pathway by ABA. Taken together, our results show that the presence of high concentrations of salt in the growth medium rapidly triggers a root-specific activation of the carotenoid pathway, probably to ensure a proper supply of ABA precursors required for a sustained production of the hormone.

Transcription of four Rhopalosiphum padi (L.) heat shock protein genes and their responses to heat stress and insecticide exposure.

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Li, Yuting; Zhao, Qi; Duan, Xinle; Song, Chunman; Chen, Maohua

2017-03-01

The bird cherry-oat aphid, Rhopalosiphum padi (L.), a worldwide destructive pest, is more heat tolerant than other wheat aphids, and it has developed resistance to different insecticides. Heat shock proteins (HSPs) play an important role in coping with environmental stresses. To investigate Hsp transcriptional responses to heat and insecticide stress, four full-length Hsp genes from R. padi (RpHsp60, RpHsc70, RpHsp70-1, and RpHsp70-2) were cloned. Four RpHsps were expressed during all R. padi developmental stages, but at varying levels. The mRNA levels of RpHsps were increased under thermal stress and reached maximal induction at a lower temperature (36°C) in the alate morph than in the apterous morph (37°C or 38°C). RpHsp expressions under heat stress suggest that RpHsp70-1 and RpHsp70-2 are inducible in both apterous and alate morphs, RpHsc70 is only heat-inducible in apterous morph, and RpHsp60 exhibits poor sensitivity to heat stress. The pretreatment at 37°C significantly increase both the survival rate and the RpHsps expression level of R. padi at subsequent lethal temperature. Under exposure to two sublethal concentrations (LC 10 and LC 30 ) of beta-cypermethrin, both RpHsp70-1 and RpHsp70-2 expressions were induced and reached a maximum 24h after exposure. In contrast, expression of RpHsp60 was not induced by either sublethal concentration of beta-cypermethrin. Moreover, the responses of RpHsp70-1 and RpHsp70-2 to heat shock were more sensitive than those to beta-cypermethrin. These results suggest that induction of RpHsp expression is related to thermal tolerance, and that RpHsp70-1 and RpHsp70-2 are the primary genes involved in the response to both heat and pesticide stress. Copyright © 2016 Elsevier Inc. All rights reserved.

The effects of CCK-8S on spatial memory and long-term potentiation at CA1 during induction of stress in rats.

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Sadeghi, Malihe; Reisi, Parham; Radahmadi, Maryam

2017-12-01

Cholecystokinin (CCK) has been proposed as a mediator in stress. However, it is still not fully documented what are its effects. We aimed to evaluate the effects of systemic administration of CCK exactly before induction of stress on spatial memory and synaptic plasticity at CA1 in rats. Male Wistar rats were divided into 4 groups: the control, the control-CCK, the stress and the stress-CCK. Restraint stress was induced 6 hr per day, for 24 days. Cholecystokinin sulfated octapeptide (CCK-8S) was injected (1.6 µg/kg, IP) before each session of stress induction. Spatial memory was evaluated by Morris water maze test. Long-term potentiation (LTP) in Schaffer collateral-CA1 synapses was assessed (by 100 Hz tetanization) in order to investigate synaptic plasticity. Stress impaired spatial memory significantly ( P stress group. With respect to the control group, both fEPSP amplitude and slope were significantly ( P stress group. However, there were no differences between responses of the control-CCK and Stress-CCK groups compared to the control group. The present results suggest that high levels of CCK-8S during induction of stress can modulate the destructive effects of stress on hippocampal synaptic plasticity and memory. Therefore, the mediatory effects of CCK in stress are likely as compensatory responses.

Selection of relatively exact reference genes for gene expression studies in goosegrass (Eleusine indica) under herbicide stress.

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Chen, Jingchao; Huang, Zhaofeng; Huang, Hongjuan; Wei, Shouhui; Liu, Yan; Jiang, Cuilan; Zhang, Jie; Zhang, Chaoxian

2017-04-21

Goosegrass (Eleusine indica) is one of the most serious annual grassy weeds worldwide, and its evolved herbicide-resistant populations are more difficult to control. Quantitative real-time PCR (qPCR) is a common technique for investigating the resistance mechanism; however, there is as yet no report on the systematic selection of stable reference genes for goosegrass. This study proposed to test the expression stability of 9 candidate reference genes in goosegrass in different tissues and developmental stages and under stress from three types of herbicide. The results show that for different developmental stages and organs (control), eukaryotic initiation factor 4 A (eIF-4) is the most stable reference gene. Chloroplast acetolactate synthase (ALS) is the most stable reference gene under glyphosate stress. Under glufosinate stress, eIF-4 is the best reference gene. Ubiquitin-conjugating enzyme (UCE) is the most stable reference gene under quizalofop-p-ethyl stress. The gene eIF-4 is the recommended reference gene for goosegrass under the stress of all three herbicides. Moreover, pairwise analysis showed that seven reference genes were sufficient to normalize the gene expression data under three herbicides treatment. This study provides a list of reliable reference genes for transcript normalization in goosegrass, which will facilitate resistance mechanism studies in this weed species.

[Regulation of heat shock gene expression in response to stress].

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Garbuz, D G

2017-01-01

Heat shock (HS) genes, or stress genes, code for a number of proteins that collectively form the most ancient and universal stress defense system. The system determines the cell capability of adaptation to various adverse factors and performs a variety of auxiliary functions in normal physiological conditions. Common stress factors, such as higher temperatures, hypoxia, heavy metals, and others, suppress transcription and translation for the majority of genes, while HS genes are upregulated. Transcription of HS genes is controlled by transcription factors of the HS factor (HSF) family. Certain HSFs are activated on exposure to higher temperatures or other adverse factors to ensure stress-induced HS gene expression, while other HSFs are specifically activated at particular developmental stages. The regulation of the main mammalian stress-inducible factor HSF1 and Drosophila melanogaster HSF includes many components, such as a variety of early warning signals indicative of abnormal cell activity (e.g., increases in intracellular ceramide, cytosolic calcium ions, or partly denatured proteins); protein kinases, which phosphorylate HSFs at various Ser residues; acetyltransferases; and regulatory proteins, such as SUMO and HSBP1. Transcription factors other than HSFs are also involved in activating HS gene transcription; the set includes D. melanogaster GAF, mammalian Sp1 and NF-Y, and other factors. Transcription of several stress genes coding for molecular chaperones of the glucose-regulated protein (GRP) family is predominantly regulated by another stress-detecting system, which is known as the unfolded protein response (UPR) system and is activated in response to massive protein misfolding in the endoplasmic reticulum and mitochondrial matrix. A translational fine tuning of HS protein expression occurs via changing the phosphorylation status of several proteins involved in translation initiation. In addition, specific signal sequences in the 5'-UTRs of some HS

Dehydration stress memory genes of Zea mays; comparison with Arabidopsis thaliana

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2014-01-01

Background Pre-exposing plants to diverse abiotic stresses may alter their physiological and transcriptional responses to a subsequent stress, suggesting a form of “stress memory”. Arabidopsis thaliana plants that have experienced multiple exposures to dehydration stress display transcriptional behavior suggesting “memory” from an earlier stress. Genes that respond to a first stress by up-regulating or down-regulating their transcription but in a subsequent stress provide a significantly different response define the ‘memory genes’ category. Genes responding similarly to each stress form the ‘non-memory’ category. It is unknown whether such memory responses exists in other Angiosperm lineages and whether memory is an evolutionarily conserved response to repeated dehydration stresses. Results Here, we determine the transcriptional responses of maize (Zea mays L.) plants that have experienced repeated exposures to dehydration stress in comparison with plants encountering the stress for the first time. Four distinct transcription memory response patterns similar to those displayed by A. thaliana were revealed. The most important contribution is the evidence that monocot and eudicot plants, two lineages that have diverged 140 to 200 M years ago, display similar abilities to ‘remember’ a dehydration stress and to modify their transcriptional responses, accordingly. The highly sensitive RNA-Seq analyses allowed to identify genes that function similarly in the two lineages, as well as genes that function in species-specific ways. Memory transcription patterns indicate that the transcriptional behavior of responding genes under repeated stresses is different from the behavior during an initial dehydration stress, suggesting that stress memory is a complex phenotype resulting from coordinated responses of multiple signaling pathways. Conclusions Structurally related genes displaying the same memory responses in the two species would suggest conservation

Stress-related clinical pain and mood in women with chronic pain: moderating effects of depression and positive mood induction.

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Davis, Mary C; Thummala, Kirti; Zautra, Alex J

2014-08-01

Chronic pain with comorbid depression is characterized by poor mood regulation and stress-related pain. This study aims to compare depressed and non-depressed pain patients in mood and pain stress reactivity and recovery, and test whether a post-stress positive mood induction moderates pain recovery. Women with fibromyalgia and/or osteoarthritis (N = 110) underwent interpersonal stress and were then randomly assigned by pain condition and depression status, assessed via the Center for Epidemiological Studies-Depression scale, to positive versus neutral mood induction. Depression did not predict stress-related reactivity in despondency, joviality, or clinical pain. However, depression × mood condition predicted recovery in joviality and clinical pain; depressed women recovered only in the positive mood condition, whereas non-depressed women recovered in both mood conditions. Depression does not alter pain and mood stress reactivity, but does impair recovery. Boosting post-stress jovial mood ameliorates pain recovery deficits in depressed patients, a finding relevant to chronic pain interventions.

Gene-expression analysis of cold-stress response in the sexually transmitted protist Trichomonas vaginalis.

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Fang, Yi-Kai; Huang, Kuo-Yang; Huang, Po-Jung; Lin, Rose; Chao, Mei; Tang, Petrus

2015-12-01

Trichomonas vaginalis is the etiologic agent of trichomoniasis, the most common nonviral sexually transmitted disease in the world. This infection affects millions of individuals worldwide annually. Although direct sexual contact is the most common mode of transmission, increasing evidence indicates that T. vaginalis can survive in the external environment and can be transmitted by contaminated utensils. We found that the growth of T. vaginalis under cold conditions is greatly inhibited, but recovers after placing these stressed cells at the normal cultivation temperature of 37 °C. However, the mechanisms by which T. vaginalis regulates this adaptive process are unclear. An expressed sequence tag (EST) database generated from a complementary DNA library of T. vaginalis messenger RNAs expressed under cold-culture conditions (4 °C, TvC) was compared with a previously published normal-cultured EST library (37 °C, TvE) to assess the cold-stress responses of T. vaginalis. A total of 9780 clones were sequenced from the TvC library and were mapped to 2934 genes in the T. vaginalis genome. A total of 1254 genes were expressed in both the TvE and TvC libraries, and 1680 genes were only found in the TvC library. A functional analysis showed that cold temperature has effects on many cellular mechanisms, including increased H2O2 tolerance, activation of the ubiquitin-proteasome system, induction of iron-sulfur cluster assembly, and reduced energy metabolism and enzyme expression. The current study is the first large-scale transcriptomic analysis in cold-stressed T. vaginalis and the results enhance our understanding of this important protist. Copyright © 2014. Published by Elsevier B.V.

Microarray analysis of expression of cell death-associated genes in rat spinal cord cells exposed to cyclic tensile stresses in vitro

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Roberts Sally

2010-07-01

Full Text Available Abstract Background The application of mechanical insults to the spinal cord results in profound cellular and molecular changes, including the induction of neuronal cell death and altered gene expression profiles. Previous studies have described alterations in gene expression following spinal cord injury, but the specificity of this response to mechanical stimuli is difficult to investigate in vivo. Therefore, we have investigated the effect of cyclic tensile stresses on cultured spinal cord cells from E15 Sprague-Dawley rats, using the FX3000® Flexercell Strain Unit. We examined cell morphology and viability over a 72 hour time course. Microarray analysis of gene expression was performed using the Affymetrix GeneChip System®, where categorization of identified genes was performed using the Gene Ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG systems. Changes in expression of 12 genes were validated with quantitative real-time reverse transcription polymerase chain reaction (RT-PCR. Results The application of cyclic tensile stress reduced the viability of cultured spinal cord cells significantly in a dose- and time-dependent manner. Increasing either the strain or the strain rate independently was associated with significant decreases in spinal cord cell survival. There was no clear evidence of additive effects of strain level with strain rate. GO analysis identified 44 candidate genes which were significantly related to "apoptosis" and 17 genes related to "response to stimulus". KEGG analysis identified changes in the expression levels of 12 genes of the mitogen-activated protein kinase (MAPK signaling pathway, which were confirmed to be upregulated by RT-PCR analysis. Conclusions We have demonstrated that spinal cord cells undergo cell death in response to cyclic tensile stresses, which were dose- and time-dependent. In addition, we have identified the up regulation of various genes, in particular of the MAPK pathway, which

Anti-oxidative stress regulator NF-E2-related factor 2 mediates the adaptive induction of antioxidant and detoxifying enzymes by lipid peroxidation metabolite 4-hydroxynonenal

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Huang Ying

2012-11-01

Full Text Available Abstract Background NF-E2-related factor 2 (NRF2 regulates a battery of antioxidative and phase II drug metabolizing/detoxifying genes through binding to the antioxidant response elements (ARE. NRF2-ARE signaling plays a central role in protecting cells from a wide spectrum of reactive toxic species including reactive oxygen/nitrogen species (RONS. 4-hydroxylnonenal (4-HNE is a major end product from lipid peroxidation of omega-6 polyunsaturated fatty acids (PUFA induced by oxidative stress, and it is highly reactive to nucleophilic sites in DNA and proteins, causing cytotoxicity and genotoxicity. In this study, we examined the role of NRF2 in regulating the 4-HNE induced gene expression of antioxidant and detoxifying enzymes. Results When HeLa cells were treated with 4-HNE, NRF2 rapidly transloated into the nucleus, as determined by the distribution of NRF2 tagged with the enhanced green fluorescent protein (EGFP and increased NRF2 protein in the nuclear fraction. Transcriptional activity of ARE-luciferase was significantly induced by 0.01-10 μM of 4-HNE in a dose-dependent manner, and the induction could be blocked by pretreatment with glutathione (GSH. 4-HNE induced transcriptional expression of glutathione S-transferase (GST A4, aldoketone reductase (AKR 1C1 and heme oxygenase-1 (HO-1, and the induction was attenuated by knocking down NRF2 using small interfering RNA. Conclusions NRF2 is critical in mediating 4-HNE induced expression of antioxidant and detoxifying genes. This may account for one of the major cellular defense mechanisms against reactive metabolites of lipids peroxidation induced by oxidative stress and protect cells from cytotoxicity.

Induction of the early-late Ddc gene during Drosophila metamorphosis by the ecdysone receptor.

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Chen, Li; Reece, Christian; O'Keefe, Sandra L; Hawryluk, Gregory W L; Engstrom, Monica M; Hodgetts, Ross B

2002-06-01

During Drosophila metamorphosis, the 'early-late' genes constitute a unique class regulated by the steroid hormone 20-hydroxyecdysone. Their induction is comprised of both a primary and a secondary response to ecdysone. Previous work has suggested that the epidermal expression of the dopa decarboxylase gene (Ddc) is likely that of a typical early-late gene. Accumulation of the Ddc transcript is rapidly initiated in the absence of protein synthesis, which implies that the ecdysone receptor plays a direct role in induction. However, full Ddc expression requires the participation of one of the transcription factors encoded by the Broad-Complex. In this paper, we characterize an ecdysone response element (EcRE) that contributes to the primary response. Using gel mobility shift assays and transgenic assays, we identified a single functional EcRE, located at position -97 to -83 bp relative to the transcription initiation site. This is the first report of an EcRE associated with an early-late gene in Drosophila. Competition experiments indicated that the affinity of the Ddc EcRE for the ecdysone receptor complex was at least four-fold less than that of the canonical EcRE of the hsp27 gene. Using in vitro mutagenesis, we determined that the reduced affinity of the EcRE resided at two positions where the nucleotides differed from those found in the canonical sequence. The ecdysone receptor, acting through this EcRE, releases Ddc from a silencing mechanism, whose cis-acting domain we have mapped to the 5'-upstream region between -2067 and -1427 bp. Deletion of this repressive element resulted in precocious expression of Ddc in both epidermis and imaginal discs. Thus, epidermal Ddc induction at pupariation is under the control of an extended genomic region that contains both positive and negative regulatory elements. Copyright 2002 Elsevier Science Ireland Ltd.

Induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway delays the initiation but fails to eradicate established murine acute myeloid leukemia.

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Jaako, P; Ugale, A; Wahlestedt, M; Velasco-Hernandez, T; Cammenga, J; Lindström, M S; Bryder, D

2017-01-01

Mutations resulting in constitutive activation of signaling pathways that regulate ribosome biogenesis are among the most common genetic events in acute myeloid leukemia (AML). However, whether ribosome biogenesis presents as a therapeutic target to treat AML remains unexplored. Perturbations in ribosome biogenesis trigger the 5S ribonucleoprotein particle (RNP)-Mdm2-p53 ribosomal stress pathway, and induction of this pathway has been shown to have therapeutic efficacy in Myc-driven lymphoma. In the current study we address the physiological and therapeutic role of the 5S RNP-Mdm2-p53 pathway in AML. By utilizing mice that have defective ribosome biogenesis due to downregulation of ribosomal protein S19 (Rps19), we demonstrate that induction of the 5S RNP-Mdm2-p53 pathway significantly delays the initiation of AML. However, even a severe Rps19 deficiency that normally results in acute bone marrow failure has no consistent efficacy on already established disease. Finally, by using mice that harbor a mutation in the Mdm2 gene disrupting its binding to 5S RNP, we show that loss of the 5S RNP-Mdm2-p53 pathway is dispensable for development of AML. Our study suggests that induction of the 5S RNP-Mdm2-p53 ribosomal stress pathway holds limited potential as a single-agent therapy in the treatment of AML.

Beginning Teachers' Self-Efficacy and Stress and the Supposed Effects of Induction Arrangements

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Helms-Lorenz, Michelle; Slof, Bert; Vermue, Carlien E.; Canrinus, Esther T.

2012-01-01

Induction arrangements are implemented in schools all over the world to support beginning teachers (BTs) (novices) in gradually growing into their profession. The aim of this study is to gain more insight into two key psychological processes involved in the work of a qualified beginning teacher, namely perceived stress and self-efficacy. This…

Expression of Aluminum-Induced Genes in Transgenic Arabidopsis Plants Can Ameliorate Aluminum Stress and/or Oxidative Stress1

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Ezaki, Bunichi; Gardner, Richard C.; Ezaki, Yuka; Matsumoto, Hideaki

2000-01-01

To examine the biological role of Al-stress-induced genes, nine genes derived from Arabidopsis, tobacco (Nicotiana tabacum L.), wheat (Triticum aestivum L.), and yeast (Saccharomyces cerevisiae) were expressed in Arabidopsis ecotype Landsberg. Lines containing eight of these genes were phenotypically normal and were tested in root elongation assays for their sensitivity to Al, Cd, Cu, Na, Zn, and to oxidative stresses. An Arabidopsis blue-copper-binding protein gene (AtBCB), a tobacco glutathione S-transferase gene (parB), a tobacco peroxidase gene (NtPox), and a tobacco GDP-dissociation inhibitor gene (NtGDI1) conferred a degree of resistance to Al. Two of these genes, AtBCB and parB, and a peroxidase gene from Arabidopsis (AtPox) also showed increased resistance to oxidative stress induced by diamide, while parB conferred resistance to Cu and Na. Al content of Al-treated root tips was reduced in the four Al-resistant plant lines compared with wild-type Ler-0, as judged by morin staining. All four Al-resistant lines also showed reduced staining of roots with 2′,7′-dichloro fluorescein diacetate (H2DCFDA), an indicator of oxidative stress. We conclude that Al-induced genes can serve to protect against Al toxicity, and also provide genetic evidence for a link between Al stress and oxidative stress in plants. PMID:10712528

Time-course profiling of molecular stress responses to silver nanoparticles in the earthworm Eisenia fetida

DEFF Research Database (Denmark)

Hayashi, Yuya; Heckmann, Lars-Henrik; Simonsen, Vibeke

2013-01-01

) with reference to dissolved silver salt (AgNO3). Principal component analysis of selected gene and enzyme response profiles revealed dissimilar patterns between AgNO3 and AgNP treatments and also over time. Despite the observed difference in molecular profiles, the body burdens of total Ag were within the same...... range (10–40 mg/kg dry weight worm) for both treatments with apparent correlation to the induction pattern of metallothionein. AgNO3 induced the genes and enzymes related to oxidative stress at day 1, after which markers of energy metabolism were all suppressed at day 2. Exposure to AgNPs likewise led...... to induction of oxidative stress genes at day 2, but with a temporal pattern shift to immune genes at day 14 following metabolic upregulation at day 7. The involvement of oxidative stress and subsequent alterations in immune gene regulation were as predicted by our in vitro study reported previously...

Selection of Reference Genes for qRT-PCR Analysis of Gene Expression in Stipa grandis during Environmental Stresses.

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Dongli Wan

Full Text Available Stipa grandis P. Smirn. is a dominant plant species in the typical steppe of the Xilingole Plateau of Inner Mongolia. Selection of suitable reference genes for the quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR is important for gene expression analysis and research into the molecular mechanisms underlying the stress responses of S. grandis. In the present study, 15 candidate reference genes (EF1 beta, ACT, GAPDH, SamDC, CUL4, CAP, SNF2, SKIP1, SKIP5, SKIP11, UBC2, UBC15, UBC17, UCH, and HERC2 were evaluated for their stability as potential reference genes for qRT-PCR under different stresses. Four algorithms were used: GeNorm, NormFinder, BestKeeper, and RefFinder. The results showed that the most stable reference genes were different under different stress conditions: EF1beta and UBC15 during drought and salt stresses; ACT and GAPDH under heat stress; SKIP5 and UBC17 under cold stress; UBC15 and HERC2 under high pH stress; UBC2 and UBC15 under wounding stress; EF1beta and UBC17 under jasmonic acid treatment; UBC15 and CUL4 under abscisic acid treatment; and HERC2 and UBC17 under salicylic acid treatment. EF1beta and HERC2 were the most suitable genes for the global analysis of all samples. Furthermore, six target genes, SgPOD, SgPAL, SgLEA, SgLOX, SgHSP90 and SgPR1, were selected to validate the most and least stable reference genes under different treatments. Our results provide guidelines for reference gene selection for more accurate qRT-PCR quantification and will promote studies of gene expression in S. grandis subjected to environmental stress.

A transcriptional analysis of carotenoid, chlorophyll and plastidial isoprenoid biosynthesis genes during development and osmotic stress responses in Arabidopsis thaliana

KAUST Repository

Meier, Stuart; Tzfadia, Oren; Vallabhaneni, Ratnakar; Gehring, Christoph A; Wurtzel, Eleanore T

2011-01-01

Background: The carotenoids are pure isoprenoids that are essential components of the photosynthetic apparatus and are coordinately synthesized with chlorophylls in chloroplasts. However, little is known about the mechanisms that regulate carotenoid biosynthesis or the mechanisms that coordinate this synthesis with that of chlorophylls and other plastidial synthesized isoprenoid-derived compounds, including quinones, gibberellic acid and abscisic acid. Here, a comprehensive transcriptional analysis of individual carotenoid and isoprenoid-related biosynthesis pathway genes was performed in order to elucidate the role of transcriptional regulation in the coordinated synthesis of these compounds and to identify regulatory components that may mediate this process in Arabidopsis thaliana.Results: A global microarray expression correlation analysis revealed that the phytoene synthase gene, which encodes the first dedicated and rate-limiting enzyme of carotenogenesis, is highly co-expressed with many photosynthesis-related genes including many isoprenoid-related biosynthesis pathway genes. Chemical and mutant analysis revealed that induction of the co-expressed genes following germination was dependent on gibberellic acid and brassinosteroids (BR) but was inhibited by abscisic acid (ABA). Mutant analyses further revealed that expression of many of the genes is suppressed in dark grown plants by Phytochrome Interacting transcription Factors (PIFs) and activated by photoactivated phytochromes, which in turn degrade PIFs and mediate a coordinated induction of the genes. The promoters of PSY and the co-expressed genes were found to contain an enrichment in putative BR-auxin response elements and G-boxes, which bind PIFs, further supporting a role for BRs and PIFs in regulating expression of the genes. In osmotically stressed root tissue, transcription of Calvin cycle, methylerythritol 4-phosphate pathway and carotenoid biosynthesis genes is induced and uncoupled from that of

A transcriptional analysis of carotenoid, chlorophyll and plastidial isoprenoid biosynthesis genes during development and osmotic stress responses in Arabidopsis thaliana

KAUST Repository

Meier, Stuart

2011-05-19

Background: The carotenoids are pure isoprenoids that are essential components of the photosynthetic apparatus and are coordinately synthesized with chlorophylls in chloroplasts. However, little is known about the mechanisms that regulate carotenoid biosynthesis or the mechanisms that coordinate this synthesis with that of chlorophylls and other plastidial synthesized isoprenoid-derived compounds, including quinones, gibberellic acid and abscisic acid. Here, a comprehensive transcriptional analysis of individual carotenoid and isoprenoid-related biosynthesis pathway genes was performed in order to elucidate the role of transcriptional regulation in the coordinated synthesis of these compounds and to identify regulatory components that may mediate this process in Arabidopsis thaliana.Results: A global microarray expression correlation analysis revealed that the phytoene synthase gene, which encodes the first dedicated and rate-limiting enzyme of carotenogenesis, is highly co-expressed with many photosynthesis-related genes including many isoprenoid-related biosynthesis pathway genes. Chemical and mutant analysis revealed that induction of the co-expressed genes following germination was dependent on gibberellic acid and brassinosteroids (BR) but was inhibited by abscisic acid (ABA). Mutant analyses further revealed that expression of many of the genes is suppressed in dark grown plants by Phytochrome Interacting transcription Factors (PIFs) and activated by photoactivated phytochromes, which in turn degrade PIFs and mediate a coordinated induction of the genes. The promoters of PSY and the co-expressed genes were found to contain an enrichment in putative BR-auxin response elements and G-boxes, which bind PIFs, further supporting a role for BRs and PIFs in regulating expression of the genes. In osmotically stressed root tissue, transcription of Calvin cycle, methylerythritol 4-phosphate pathway and carotenoid biosynthesis genes is induced and uncoupled from that of

A transcriptional analysis of carotenoid, chlorophyll and plastidial isoprenoid biosynthesis genes during development and osmotic stress responses in Arabidopsis thaliana

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Vallabhaneni Ratnakar

2011-05-01

Full Text Available Abstract Background The carotenoids are pure isoprenoids that are essential components of the photosynthetic apparatus and are coordinately synthesized with chlorophylls in chloroplasts. However, little is known about the mechanisms that regulate carotenoid biosynthesis or the mechanisms that coordinate this synthesis with that of chlorophylls and other plastidial synthesized isoprenoid-derived compounds, including quinones, gibberellic acid and abscisic acid. Here, a comprehensive transcriptional analysis of individual carotenoid and isoprenoid-related biosynthesis pathway genes was performed in order to elucidate the role of transcriptional regulation in the coordinated synthesis of these compounds and to identify regulatory components that may mediate this process in Arabidopsis thaliana. Results A global microarray expression correlation analysis revealed that the phytoene synthase gene, which encodes the first dedicated and rate-limiting enzyme of carotenogenesis, is highly co-expressed with many photosynthesis-related genes including many isoprenoid-related biosynthesis pathway genes. Chemical and mutant analysis revealed that induction of the co-expressed genes following germination was dependent on gibberellic acid and brassinosteroids (BR but was inhibited by abscisic acid (ABA. Mutant analyses further revealed that expression of many of the genes is suppressed in dark grown plants by Phytochrome Interacting transcription Factors (PIFs and activated by photoactivated phytochromes, which in turn degrade PIFs and mediate a coordinated induction of the genes. The promoters of PSY and the co-expressed genes were found to contain an enrichment in putative BR-auxin response elements and G-boxes, which bind PIFs, further supporting a role for BRs and PIFs in regulating expression of the genes. In osmotically stressed root tissue, transcription of Calvin cycle, methylerythritol 4-phosphate pathway and carotenoid biosynthesis genes is induced

Transcriptomic analysis of salt stress responsive genes in Rhazya stricta.

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Nahid H Hajrah

Full Text Available Rhazya stricta is an evergreen shrub that is widely distributed across Western and South Asia, and like many other members of the Apocynaceae produces monoterpene indole alkaloids that have anti-cancer properties. This species is adapted to very harsh desert conditions making it an excellent system for studying tolerance to high temperatures and salinity. RNA-Seq analysis was performed on R. stricta exposed to severe salt stress (500 mM NaCl across four time intervals (0, 2, 12 and 24 h to examine mechanisms of salt tolerance. A large number of transcripts including genes encoding tetrapyrroles and pentatricopeptide repeat (PPR proteins were regulated only after 12 h of stress of seedlings grown in controlled greenhouse conditions. Mechanisms of salt tolerance in R. stricta may involve the upregulation of genes encoding chaperone protein Dnaj6, UDP-glucosyl transferase 85a2, protein transparent testa 12 and respiratory burst oxidase homolog protein b. Many of the highly-expressed genes act on protecting protein folding during salt stress and the production of flavonoids, key secondary metabolites in stress tolerance. Other regulated genes encode enzymes in the porphyrin and chlorophyll metabolic pathway with important roles during plant growth, photosynthesis, hormone signaling and abiotic responses. Heme biosynthesis in R. stricta leaves might add to the level of salt stress tolerance by maintaining appropriate levels of photosynthesis and normal plant growth as well as by the participation in reactive oxygen species (ROS production under stress. We speculate that the high expression levels of PPR genes may be dependent on expression levels of their targeted editing genes. Although the results of PPR gene family indicated regulation of a large number of transcripts under salt stress, PPR actions were independent of the salt stress because their RNA editing patterns were unchanged.

Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5

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Eline Saenen

2015-06-01

Full Text Available To evaluate the environmental impact of uranium (U contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed.

Effects of stress and MDMA on hippocampal gene expression.

Science.gov (United States)

Weber, Georg F; Johnson, Bethann N; Yamamoto, Bryan K; Gudelsky, Gary A

2014-01-01

MDMA (3,4-methylenedioxymethamphetamine) is a substituted amphetamine and popular drug of abuse. Its mood-enhancing short-term effects may prompt its consumption under stress. Clinical studies indicate that MDMA treatment may mitigate the symptoms of stress disorders such as posttraumatic stress syndrome (PTSD). On the other hand, repeated administration of MDMA results in persistent deficits in markers of serotonergic (5-HT) nerve terminals that have been viewed as indicative of 5-HT neurotoxicity. Exposure to chronic stress has been shown to augment MDMA-induced 5-HT neurotoxicity. Here, we examine the transcriptional responses in the hippocampus to MDMA treatment of control rats and rats exposed to chronic stress. MDMA altered the expression of genes that regulate unfolded protein binding, protein folding, calmodulin-dependent protein kinase activity, and neuropeptide signaling. In stressed rats, the gene expression profile in response to MDMA was altered to affect sensory processing and responses to tissue damage in nerve sheaths. Subsequent treatment with MDMA also markedly altered the genetic responses to stress such that the stress-induced downregulation of genes related to the circadian rhythm was reversed. The data support the view that MDMA-induced transcriptional responses accompany the persistent effects of this drug on neuronal structure/function. In addition, MDMA treatment alters the stress-induced transcriptional signature.

Silencing of DNase Colicin E8 Gene Expression by a Complex Nucleoprotein Assembly Ensures Timely Colicin Induction.

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Simona Kamenšek

2015-06-01

Full Text Available Colicins are plasmid-encoded narrow spectrum antibiotics that are synthesized by strains of Escherichia coli and govern intraspecies competition. In a previous report, we demonstrated that the global transcriptional factor IscR, co dependently with the master regulator of the DNA damage response, LexA, delays induction of the pore forming colicin genes after SOS induction. Here we show that IscR is not involved in the regulation of nuclease colicins, but that the AsnC protein is. We report that AsnC, in concert with LexA, is the key controller of the temporal induction of the DNA degrading colicin E8 gene (cea8, after DNA damage. We demonstrate that a large AsnC nucleosome-like structure, in conjunction with two LexA molecules, prevent cea8 transcription initiation and that AsnC binding activity is directly modulated by L asparagine. We show that L-asparagine is an environmental factor that has a marked impact on cea8 promoter regulation. Our results show that AsnC also modulates the expression of several other DNase and RNase colicin genes but does not substantially affect pore-forming colicin K gene expression. We propose that selection pressure has "chosen" highly conserved regulators to control colicin expression in E. coli strains, enabling similar colicin gene silencing among bacteria upon exchange of colicinogenic plasmids.

Differential induction of heme oxygenase and other stress proteins in cultured hippocampal astrocytes and neurons by inorganic lead

International Nuclear Information System (INIS)

Cabell, Leigh; Ferguson, Charles; Luginbill, Deana; Kern, Marcey; Weingart, Adam; Audesirk, Gerald

2004-01-01

We examined the effects of exposure to inorganic lead (Pb 2+ ) on the induction of stress proteins in cultured hippocampal neurons and astrocytes, with particular emphasis on the induction of heme oxygenase-1 (HO-1). In radiolabeled neuronal cultures, Pb 2+ exposure had no significant effect on the synthesis of any protein at any concentration (up to 250 μM) or duration of exposure (up to 4 days). In radiolabeled astrocyte cultures, however, Pb 2+ exposure (100 nM to 100 μM; 1-4 days) increased synthesis of proteins with approximate molecular weights of 23, 32, 45, 57, 72, and 90 kDa. Immunoblot experiments showed that Pb 2+ exposure (100 nM to 10 μM, 1-14 days) induces HO-1 synthesis in astrocytes, but not in neurons; this is probably the 32-kDa protein. The other heme oxygenase isoform, HO-2, is present in both neurons and astrocytes, but is not inducible by Pb 2+ at concentrations up to 100 μM. HO-1 can be induced by a variety of stimuli. We found that HO-1 induction in astrocytes is increased by combined exposure to Pb 2+ and many other stresses, including heat, nitric oxide, H 2 O 2 , and superoxide. One of the stimuli that may induce HO-1 is oxidative stress. Lead exposure causes oxidative stress in many cell types, including astrocytes. Induction of HO-1 by Pb 2+ is reduced by the hydroxyl radical scavengers dimethylthiourea (DMTU) and mannitol, but not by inhibitors of calmodulin, calmodulin-dependent protein kinases, protein kinase C, or extracellular signal-regulated kinases (ERK). Therefore, we conclude that oxidative stress is an important mechanism by which Pb 2+ induces HO-1 synthesis in astrocytes

Phytohormones and induction of plant-stress tolerance and defense genes by seed and foliar inoculation with Azospirillum brasilense cells and metabolites promote maize growth.

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Fukami, Josiane; Ollero, Francisco Javier; Megías, Manuel; Hungria, Mariangela

2017-12-01

Azospirillum spp. are plant-growth-promoting bacteria used worldwide as inoculants for a variety of crops. Among the beneficial mechanisms associated with Azospirillum inoculation, emphasis has been given to the biological nitrogen fixation process and to the synthesis of phytohormones. In Brazil, the application of inoculants containing A. brasilense strains Ab-V5 and Ab-V6 to cereals is exponentially growing and in this study we investigated the effects of maize inoculation with these two strains applied on seeds or by leaf spray at the V2.5 stage growth-a strategy to relieve incompatibility with pesticides used for seed treatment. We also investigate the effects of spraying the metabolites of these two strains at V2.5. Maize growth was promoted by the inoculation of bacteria and their metabolites. When applied via foliar spray, although A. brasilense survival on leaves was confirmed by confocal microscopy and cell recovery, few cells were detected after 24 h, indicating that the effects of bacterial leaf spray might also be related to their metabolites. The major molecules detected in the supernatants of both strains were indole-3-acetic acid, indole-3-ethanol, indole-3-lactic acid and salicylic acid. RT-PCR of genes related to oxidative stress (APX1, APX2, CAT1, SOD2, SOD4) and plant defense (pathogenesis-related PR1, prp2 and prp4) was evaluated on maize leaves and roots. Differences were observed according to the gene, plant tissue, strain and method of application, but, in general, inoculation with Azospirillum resulted in up-regulation of oxidative stress genes in leaves and down-regulation in roots; contrarily, in general, PR genes were down-regulated in leaves and up-regulated in roots. Emphasis should be given to the application of metabolites, especially of Ab-V5 + Ab-V6 that in general resulted in the highest up-regulation of oxidative-stress and PR genes both in leaves and in roots. We hypothesize that the benefits of inoculation of Azospirillum on

Genome-wide identification and analysis of biotic and abiotic stress regulation of small heat shock protein (HSP20) family genes in bread wheat.

Science.gov (United States)

Muthusamy, Senthilkumar K; Dalal, Monika; Chinnusamy, Viswanathan; Bansal, Kailash C

2017-04-01

Small Heat Shock Proteins (sHSPs)/HSP20 are molecular chaperones that protect plants by preventing protein aggregation during abiotic stress conditions, especially heat stress. Due to global climate change, high temperature is emerging as a major threat to wheat productivity. Thus, the identification of HSP20 and analysis of HSP transcriptional regulation under different abiotic stresses in wheat would help in understanding the role of these proteins in abiotic stress tolerance. We used sequences of known rice and Arabidopsis HSP20 HMM profiles as queries against publicly available wheat genome and wheat full length cDNA databases (TriFLDB) to identify the respective orthologues from wheat. 163 TaHSP20 (including 109 sHSP and 54 ACD) genes were identified and classified according to the sub-cellular localization and phylogenetic relationship with sequenced grass genomes (Oryza sativa, Sorghum bicolor, Zea mays, Brachypodium distachyon and Setaria italica). Spatio-temporal, biotic and abiotic stress-specific expression patterns in normalized RNA seq and wheat array datasets revealed constitutive as well as inductive responses of HSP20 in different tissues and developmental stages of wheat. Promoter analysis of TaHSP20 genes showed the presence of tissue-specific, biotic, abiotic, light-responsive, circadian and cell cycle-responsive cis-regulatory elements. 14 TaHSP20 family genes were under the regulation of 8 TamiRNA genes. The expression levels of twelve HSP20 genes were studied under abiotic stress conditions in the drought- and heat-tolerant wheat genotype C306. Of the 13 TaHSP20 genes, TaHSP16.9H-CI showed high constitutive expression with upregulation only under salt stress. Both heat and salt stresses upregulated the expression of TaHSP17.4-CI, TaHSP17.7A-CI, TaHSP19.1-CIII, TaACD20.0B-CII and TaACD20.6C-CIV, while TaHSP23.7-MTI was specifically induced only under heat stress. Our results showed that the identified TaHSP20 genes play an important role under

P53-mediated rapid induction of apoptosis conveys resistance to viral infection in Drosophila melanogaster.

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Bo Liu

2013-02-01

Full Text Available Arthropod-borne pathogens account for millions of deaths each year. Understanding the genetic mechanisms controlling vector susceptibility to pathogens has profound implications for developing novel strategies for controlling insect-transmitted infectious diseases. The fact that many viruses carry genes that have anti-apoptotic activity has long led to the hypothesis that induction of apoptosis could be a fundamental innate immune response. However, the cellular mechanisms mediating the induction of apoptosis following viral infection remained enigmatic, which has prevented experimental verification of the functional significance of apoptosis in limiting viral infection in insects. In addition, studies with cultured insect cells have shown that there is sometimes a lack of apoptosis, or the pro-apoptotic response happens relatively late, thus casting doubt on the functional significance of apoptosis as an innate immunity. Using in vivo mosquito models and the native route of infection, we found that there is a rapid induction of reaper-like pro-apoptotic genes within a few hours following exposure to DNA or RNA viruses. Recapitulating a similar response in Drosophila, we found that this rapid induction of apoptosis requires the function of P53 and is mediated by a stress-responsive regulatory region upstream of reaper. More importantly, we showed that the rapid induction of apoptosis is responsible for preventing the expression of viral genes and blocking the infection. Genetic changes influencing this rapid induction of reaper-like pro-apoptotic genes led to significant differences in susceptibility to viral infection.

Effects of Stress and MDMA on Hippocampal Gene Expression

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Georg F. Weber

2014-01-01

Full Text Available MDMA (3,4-methylenedioxymethamphetamine is a substituted amphetamine and popular drug of abuse. Its mood-enhancing short-term effects may prompt its consumption under stress. Clinical studies indicate that MDMA treatment may mitigate the symptoms of stress disorders such as posttraumatic stress syndrome (PTSD. On the other hand, repeated administration of MDMA results in persistent deficits in markers of serotonergic (5-HT nerve terminals that have been viewed as indicative of 5-HT neurotoxicity. Exposure to chronic stress has been shown to augment MDMA-induced 5-HT neurotoxicity. Here, we examine the transcriptional responses in the hippocampus to MDMA treatment of control rats and rats exposed to chronic stress. MDMA altered the expression of genes that regulate unfolded protein binding, protein folding, calmodulin-dependent protein kinase activity, and neuropeptide signaling. In stressed rats, the gene expression profile in response to MDMA was altered to affect sensory processing and responses to tissue damage in nerve sheaths. Subsequent treatment with MDMA also markedly altered the genetic responses to stress such that the stress-induced downregulation of genes related to the circadian rhythm was reversed. The data support the view that MDMA-induced transcriptional responses accompany the persistent effects of this drug on neuronal structure/function. In addition, MDMA treatment alters the stress-induced transcriptional signature.

Salt stress-induced transcription of σB- and CtsR-regulated genes in persistent and non-persistent Listeria monocytogenes strains from food processing plants.

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Ringus, Daina L; Ivy, Reid A; Wiedmann, Martin; Boor, Kathryn J

2012-03-01

Listeria monocytogenes is a foodborne pathogen that can persist in food processing environments. Six persistent and six non-persistent strains from fish processing plants and one persistent strain from a meat plant were selected to determine if expression of genes in the regulons of two stress response regulators, σ(B) and CtsR, under salt stress conditions is associated with the ability of L. monocytogenes to persist in food processing environments. Subtype data were also used to categorize the strains into genetic lineages I or II. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to measure transcript levels for two σ(B)-regulated genes, inlA and gadD3, and two CtsR-regulated genes, lmo1138 and clpB, before and after (t=10 min) salt shock (i.e., exposure of exponential phase cells to BHI+6% NaCl for 10 min at 37°C). Exposure to salt stress induced higher transcript levels relative to levels under non-stress conditions for all four stress and virulence genes across all wildtype strains tested. Analysis of variance (ANOVA) of induction data revealed that transcript levels for one gene (clpB) were induced at significantly higher levels in non-persistent strains compared to persistent strains (p=0.020; two-way ANOVA). Significantly higher transcript levels of gadD3 (p=0.024; two-way ANOVA) and clpB (p=0.053; two-way ANOVA) were observed after salt shock in lineage I strains compared to lineage II strains. No clear association between stress gene transcript levels and persistence was detected. Our data are consistent with an emerging model that proposes that establishment of L. monocytogenes persistence in a specific environment occurs as a random, stochastic event, rather than as a consequence of specific bacterial strain characteristics.

Identification of differentially expressed genes in flax (Linum usitatissimum L.) under saline-alkaline stress by digital gene expression.

Science.gov (United States)

Yu, Ying; Huang, Wengong; Chen, Hongyu; Wu, Guangwen; Yuan, Hongmei; Song, Xixia; Kang, Qinghua; Zhao, Dongsheng; Jiang, Weidong; Liu, Yan; Wu, Jianzhong; Cheng, Lili; Yao, Yubo; Guan, Fengzhi

2014-10-01

The salinization and alkalization of soil are widespread environmental problems, and alkaline salt stress is more destructive than neutral salt stress. Therefore, understanding the mechanism of plant tolerance to saline-alkaline stress has become a major challenge. However, little attention has been paid to the mechanism of plant alkaline salt tolerance. In this study, gene expression profiling of flax was analyzed under alkaline-salt stress (AS2), neutral salt stress (NSS) and alkaline stress (AS) by digital gene expression. Three-week-old flax seedlings were placed in 25 mM Na2CO3 (pH11.6) (AS2), 50mM NaCl (NSS) and NaOH (pH11.6) (AS) for 18 h. There were 7736, 1566 and 454 differentially expressed genes in AS2, NSS and AS compared to CK, respectively. The GO category gene enrichment analysis revealed that photosynthesis was particularly affected in AS2, carbohydrate metabolism was particularly affected in NSS, and the response to biotic stimulus was particularly affected in AS. We also analyzed the expression pattern of five categories of genes including transcription factors, signaling transduction proteins, phytohormones, reactive oxygen species proteins and transporters under these three stresses. Some key regulatory gene families involved in abiotic stress, such as WRKY, MAPKKK, ABA, PrxR and ion channels, were differentially expressed. Compared with NSS and AS, AS2 triggered more differentially expressed genes and special pathways, indicating that the mechanism of AS2 was more complex than NSS and AS. To the best of our knowledge, this was the first transcriptome analysis of flax in response to saline-alkaline stress. These data indicate that common and diverse features of saline-alkaline stress provide novel insights into the molecular mechanisms of plant saline-alkaline tolerance and offer a number of candidate genes as potential markers of tolerance to saline-alkaline stress. Copyright © 2014 Elsevier B.V. All rights reserved.

Evolution and Stress Responses of Gossypium hirsutum SWEET Genes.

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Li, Wei; Ren, Zhongying; Wang, Zhenyu; Sun, Kuan; Pei, Xiaoyu; Liu, Yangai; He, Kunlun; Zhang, Fei; Song, Chengxiang; Zhou, Xiaojian; Zhang, Wensheng; Ma, Xiongfeng; Yang, Daigang

2018-03-08

The SWEET (sugars will eventually be exported transporters) proteins are sugar efflux transporters containing the MtN3_saliva domain, which affects plant development as well as responses to biotic and abiotic stresses. These proteins have not been functionally characterized in the tetraploid cotton, Gossypium hirsutum , which is a widely cultivated cotton species. In this study, we comprehensively analyzed the cotton SWEET gene family. A total of 55 putative G. hirsutum SWEET genes were identified. The GhSWEET genes were classified into four clades based on a phylogenetic analysis and on the examination of gene structural features. Moreover, chromosomal localization and an analysis of homologous genes in Gossypium arboreum , Gossypium raimondii , and G. hirsutum suggested that a whole-genome duplication, several tandem duplications, and a polyploidy event contributed to the expansion of the cotton SWEET gene family, especially in Clade III and IV. Analyses of cis -acting regulatory elements in the promoter regions, expression profiles, and artificial selection revealed that the GhSWEET genes were likely involved in cotton developmental processes and responses to diverse stresses. These findings may clarify the evolution of G. hirsutum SWEET gene family and may provide a foundation for future functional studies of SWEET proteins regarding cotton development and responses to abiotic stresses.

Transcriptional 'memory' of a stress: transient chromatin and memory (epigenetic) marks at stress-response genes.

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Avramova, Zoya

2015-07-01

Drought, salinity, extreme temperature variations, pathogen and herbivory attacks are recurring environmental stresses experienced by plants throughout their life. To survive repeated stresses, plants provide responses that may be different from their response during the first encounter with the stress. A different response to a similar stress represents the concept of 'stress memory'. A coordinated reaction at the organismal, cellular and gene/genome levels is thought to increase survival chances by improving the plant's tolerance/avoidance abilities. Ultimately, stress memory may provide a mechanism for acclimation and adaptation. At the molecular level, the concept of stress memory indicates that the mechanisms responsible for memory-type transcription during repeated stresses are not based on repetitive activation of the same response pathways activated by the first stress. Some recent advances in the search for transcription 'memory factors' are discussed with an emphasis on super-induced dehydration stress memory response genes in Arabidopsis. © 2015 The Author The Plant Journal © 2015 John Wiley & Sons Ltd.

Microarray meta-analysis to explore abiotic stress-specific gene expression patterns in Arabidopsis.

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Shen, Po-Chih; Hour, Ai-Ling; Liu, Li-Yu Daisy

2017-12-01

Abiotic stresses are the major limiting factors that affect plant growth, development, yield and final quality. Deciphering the underlying mechanisms of plants' adaptations to stresses using few datasets might overlook the different aspects of stress tolerance in plants, which might be simultaneously and consequently operated in the system. Fortunately, the accumulated microarray expression data offer an opportunity to infer abiotic stress-specific gene expression patterns through meta-analysis. In this study, we propose to combine microarray gene expression data under control, cold, drought, heat, and salt conditions and determined modules (gene sets) of genes highly associated with each other according to the observed expression data. By analyzing the expression variations of the Eigen genes from different conditions, we had identified two, three, and five gene modules as cold-, heat-, and salt-specific modules, respectively. Most of the cold- or heat-specific modules were differentially expressed to a particular degree in shoot samples, while most of the salt-specific modules were differentially expressed to a particular degree in root samples. A gene ontology (GO) analysis on the stress-specific modules suggested that the gene modules exclusively enriched stress-related GO terms and that different genes under the same GO terms may be alternatively disturbed in different conditions. The gene regulatory events for two genes, DREB1A and DEAR1, in the cold-specific gene module had also been validated, as evidenced through the literature search. Our protocols study the specificity of the gene modules that were specifically activated under a particular type of abiotic stress. The biplot can also assist to visualize the stress-specific gene modules. In conclusion, our approach has the potential to further elucidate mechanisms in plants and beneficial for future experiments design under different abiotic stresses.

Induction of Pro-Apoptotic Endoplasmic Reticulum Stress in Multiple Myeloma Cells by NEO214, Perillyl Alcohol Conjugated to Rolipram.

Science.gov (United States)

Chen, Thomas C; Chan, Nymph; Labib, Shirin; Yu, Jiali; Cho, Hee-Yeon; Hofman, Florence M; Schönthal, Axel H

2018-01-17

Despite the introduction of new therapies for multiple myeloma (MM), many patients are still dying from this disease and novel treatments are urgently needed. We have designed a novel hybrid molecule, called NEO214, that was generated by covalent conjugation of the natural monoterpene perillyl alcohol (POH), an inducer of endoplasmic reticulum (ER) stress, to rolipram (Rp), an inhibitor of phosphodiesterase-4 (PDE4). Its potential anticancer effects were investigated in a panel of MM cell lines. We found that NEO214 effectively killed MM cells in vitro with a potency that was over an order of magnitude stronger than that of its individual components, either alone or in combination. The cytotoxic mechanism of NEO214 involved severe ER stress and prolonged induction of CCAAT/enhancer-binding protein homologous protein (CHOP), a key pro-apoptotic component of the ER stress response. These effects were prevented by salubrinal, a pharmacologic inhibitor of ER stress, and by CHOP gene knockout. Conversely, combination of NEO214 with bortezomib, a drug in clinical use for patients with MM, resulted in synergistic enhancement of MM cell death. Combination with the adenylate cyclase stimulant forskolin did not enhance NEO214 impact, indicating that cyclic adenosine 3',5'-monophosphate (AMP) pathways might play a lesser role. Our study introduces the novel agent NEO214 as a potent inducer of ER stress with significant anti-MM activity in vitro. It should be further investigated as a potential MM therapy aimed at exploiting this tumor's distinct sensitivity to ER stress.

Characterization of abiotic stress genes from different species of eucalyptus

International Nuclear Information System (INIS)

Naz, S.; Kausar, H.; Saleem, F.; Zafarullah, A.

2015-01-01

The stresses causing dehydration damage to the plant cell like cold, drought, and high salinity are the most frequent environmental stresses that influence plant growth, development and restraining productivity in cultivated areas world-wide. Many drought, salinity and cold inducible genes causing tolerance to environmental stresses in many plants include Dehydrin1 (DHN1), Dehydrin2 (DHN2), Dehydrin10 (DHN10), putative phosphate transporter (Ecpt2), choline monooxygenase (CMO) and DREB/CBF1c genes. Gene specific primer pairs were designed for each gene using DNAStar software. These genes were amplified from different species of eucalyptus such as Eucalyptus camaldulensis, E. globulus, E. tereticornis and E. gunii through PCR. Dehydrin2 gene of E. camaldulensis and dehydrin10 gene of E. globulus were cloned using the TA Cloning Kit with pCR 2.1 vector and sequenced. The Dehydrin genes sequences were submitted to GeneBank: Eucalyptus globulus dehydrin10 gene (Accession No. HG915712) and E. camaldulensis dehydrin 2 gene (Accession No. HG813113). The amino acid sequence of Dehydrin10 from E. globulus showed 97% homology to E. globulus DHN10 (JN052210) and Dehydrin2 from E. camaldulensis presented 94% homology to E. globulus DHN2 (JN052209). These genes can be employed in generating drought resistant crop plants. (author)

Memory responses of jasmonic acid-associated Arabidopsis genes to a repeated dehydration stress.

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Liu, Ning; Staswick, Paul E; Avramova, Zoya

2016-11-01

Dehydration stress activates numerous genes co-regulated by diverse signaling pathways. Upon repeated exposures, however, a subset of these genes does not respond maintaining instead transcription at their initial pre-stressed levels ('revised-response' genes). Most of these genes are involved in jasmonic acid (JA) biosynthesis, JA-signaling and JA-mediated stress responses. How these JA-associated genes are regulated to provide different responses to similar dehydration stresses is an enigma. Here, we investigate molecular mechanisms that contribute to this transcriptional behavior. The memory-mechanism is stress-specific: one exposure to dehydration stress or to abscisic acid (ABA) is required to prevent transcription in the second. Both ABA-mediated and JA-mediated pathways are critical for the activation of these genes, but the two signaling pathways interact differently during a single or multiple encounters with dehydration stress. Synthesis of JA during the first (S1) but not the second dehydration stress (S2) accounts for the altered transcriptional responses. We propose a model for these memory responses, wherein lack of MYC2 and of JA synthesis in S2 is responsible for the lack of expression of downstream genes. The similar length of the memory displayed by different memory-type genes suggests biological relevance for transcriptional memory as a gene-regulating mechanism during recurring bouts of drought. © 2016 John Wiley & Sons Ltd.

Acetaminophen hepatotoxicity and HIF-1α induction in acetaminophen toxicity in mice occurs without hypoxia

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Chaudhuri, Shubhra; McCullough, Sandra S.; Hennings, Leah; Letzig, Lynda; Simpson, Pippa M.; Hinson, Jack A.; James, Laura P.

2011-01-01

HIF-1α is a nuclear factor important in the transcription of genes controlling angiogenesis including vascular endothelial growth factor (VEGF). Both hypoxia and oxidative stress are known mechanisms for the induction of HIF-1α. Oxidative stress and mitochondrial permeability transition (MPT) are mechanistically important in acetaminophen (APAP) toxicity in the mouse. MPT may occur as a result of oxidative stress and leads to a large increase in oxidative stress. We previously reported the induction of HIF-1α in mice with APAP toxicity and have shown that VEGF is important in hepatocyte regeneration following APAP toxicity. The following study was performed to examine the relative contribution of hypoxia versus oxidative stress to the induction of HIF-1α in APAP toxicity in the mouse. Time course studies using the hypoxia marker pimonidazole showed no staining for pimonidazole at 1 or 2 h in B6C3F1 mice treated with APAP. Staining for pimonidazole was present in the midzonal to periportal regions at 4, 8, 24 and 48 h and no staining was observed in centrilobular hepatocytes, the sites of the toxicity. Subsequent studies with the MPT inhibitor cyclosporine A showed that cyclosporine A (CYC; 10 mg/kg) reduced HIF-1α induction in APAP treated mice at 1 and 4 h and did not inhibit the metabolism of APAP (depletion of hepatic non-protein sulfhydryls and hepatic protein adduct levels). The data suggest that HIF-1α induction in the early stages of APAP toxicity is secondary to oxidative stress via a mechanism involving MPT. In addition, APAP toxicity is not mediated by a hypoxia mechanism.

The effects of CCK-8S on spatial memory and long-term potentiation at CA1 during induction of stress in rats

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Malihe Sadeghi

2017-12-01

Full Text Available Objective(s: Cholecystokinin (CCK has been proposed as a mediator in stress. However, it is still not fully documented what are its effects. We aimed to evaluate the effects of systemic administration of CCK exactly before induction of stress on spatial memory and synaptic plasticity at CA1 in rats. Materials and Methods: Male Wistar rats were divided into 4 groups: the control, the control-CCK, the stress and the stress-CCK. Restraint stress was induced 6 hr per day, for 24 days. Cholecystokinin sulfated octapeptide (CCK-8S was injected (1.6 µg/kg, IP before each session of stress induction. Spatial memory was evaluated by Morris water maze test. Long term potentiation (LTP in Schaffer collateral-CA1 synapses was assessed (by 100 Hz tetanization in order to investigate synaptic plasticity. Results: Stress impaired spatial memory significantly (P

A novel radiation responsive cis-acting element regulates gene induction and mediates tissue injury

International Nuclear Information System (INIS)

Hallahan, Dennis E.; Virudachalam, Subbulakshmi; Kuchibahtla, Jaya

1997-01-01

Purpose: The intracellular adhesion molecule (ICAM-1) binds and activates inflammatory cells and thereby contributes to the pathogenesis of tissue injury. To characterize a model for radiation-induction of tissue injury, we studied radiation-mediated lung injury in mice deficient in the ICAM-1 gene. To study the mechanisms of x-ray mediated ICAM induction, we studied transcriptional activation of the ICAM promoter and nuclear protein binding to the 5' untranslated region of the ICAM gene. Methods: Immunohistochemistry and immunofluorescence were used to study the histologic pattern of ICAM expression in irradiated tissue. The ICAM-1 knockout mice were bred with wild type mice to create heterozygous mice with attenuated ICAM expression. ICAM -/-, ICAM+/- and ICAM +/+ mice were treated with thoracic irradiation and lung sections were stained for leukocyte common antigen (CD45) to study inflammation. To study the mechanism of x-ray induction of ICAM, we linked the 5' untranslated region of the ICAM gene to the luciferase reporter gene and delated DNA segments from the promoter to determine which elements are required for induction. We performed electrophoretic mobility shift analysis of nuclear proteins from irradiated endothelial cells to study transcription factor activation. Results: Immunohistochemistry showed dose and time dependent increases in ICAM protein expression in irradiated lungs which was prolonged as compared to endothelial cells in vitro. The histologic pattern of ICAM expression was in the capillary endothelium and was distinct from the pattern of expression of other radiation-inducible adhesion molecules. ICAM knockout mice had no ICAM expression and no inflammatory cell accumulation in the irradiated lung. ICAM+/+ mice developed leukocyte adhesion to irradiated endothelium within hours of irradiation and radiation pneumonitis 5 to 6 weeks later. The DNA sequence between -981 and -769 (relative to start codon) contains two 16-base pair repeats, each

Induction of P450 genes in Nilaparvata lugens and Sogatella furcifera by two neonicotinoid insecticides.

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Yang, Yuan-Xue; Yu, Na; Zhang, Jian-Hua; Zhang, Yi-Xi; Liu, Ze-Wen

2018-06-01

Nilaparvata lugens and Sogatella furcifera are two primary planthoppers on rice throughout Asian countries and areas. Neonicotinoid insecticides, such as imidacloprid (IMI), have been extensively used to control rice planthoppers and IMI resistance consequently occurred with an important mechanism from the over-expression of P450 genes. The induction of P450 genes by IMI may increase the ability to metabolize this insecticide in planthoppers and increase the resistance risk. In this study, the induction of P450 genes was compared in S. furcifera treated with IMI and nitromethyleneimidazole (NMI), in two planthopper species by IMI lethal dose that kills 85% of the population (LD 85 ), and in N. lugens among three IMI doses (LD 15 , LD 50 and LD 85 ). When IMI and NMI at the LD 85 dose were applied to S. furcifera, the expression changes in most P450 genes were similar, including the up-regulation of nine genes and down-regulation of three genes. In terms of the expression changes in 12 homologous P450 genes between N. lugens and S. furcifera treated with IMI at the LD 85 dose, 10 genes had very similar patterns, such as up-regulation in seven genes, down-regulation in one gene and no significant changes in two genes. When three different IMI doses were applied to N. lugens, the changes in P450 gene expression were much different, such as up-regulation in four genes at all doses and dose-dependent regulation of the other nine genes. For example, CYP6AY1 could be induced by all IMI doses, while CYP6ER1 was only up-regulated by the LD 50 dose, although both genes were reported important in IMI resistance. In conclusion, P450 genes in two planthopper species showed similar regulation patterns in responding to IMI, and the two neonicotinoid insecticides had similar effects on P450 gene expression, although the regulation was often dose-dependent. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Investigating the molecular basis of local adaptation to thermal stress: population differences in gene expression across the transcriptome of the copepod Tigriopus californicus

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Schoville Sean D

2012-09-01

Full Text Available Abstract Background Geographic variation in the thermal environment impacts a broad range of biochemical and physiological processes and can be a major selective force leading to local population adaptation. In the intertidal copepod Tigriopus californicus, populations along the coast of California show differences in thermal tolerance that are consistent with adaptation, i.e., southern populations withstand thermal stresses that are lethal to northern populations. To understand the genetic basis of these physiological differences, we use an RNA-seq approach to compare genome-wide patterns of gene expression in two populations known to differ in thermal tolerance. Results Observed differences in gene expression between the southern (San Diego and the northern (Santa Cruz populations included both the number of affected loci as well as the identity of these loci. However, the most pronounced differences concerned the amplitude of up-regulation of genes producing heat shock proteins (Hsps and genes involved in ubiquitination and proteolysis. Among the hsp genes, orthologous pairs show markedly different thermal responses as the amplitude of hsp response was greatly elevated in the San Diego population, most notably in members of the hsp70 gene family. There was no evidence of accelerated evolution at the sequence level for hsp genes. Among other sets of genes, cuticle genes were up-regulated in SD but down-regulated in SC, and mitochondrial genes were down-regulated in both populations. Conclusions Marked changes in gene expression were observed in response to acute sub-lethal thermal stress in the copepod T. californicus. Although some qualitative differences were observed between populations, the most pronounced differences involved the magnitude of induction of numerous hsp and ubiquitin genes. These differences in gene expression suggest that evolutionary divergence in the regulatory pathway(s involved in acute temperature stress may offer at

Checkpoint-dependent RNR induction promotes fork restart after replicative stress.

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Morafraile, Esther C; Diffley, John F X; Tercero, José Antonio; Segurado, Mónica

2015-01-20

The checkpoint kinase Rad53 is crucial to regulate DNA replication in the presence of replicative stress. Under conditions that interfere with the progression of replication forks, Rad53 prevents Exo1-dependent fork degradation. However, although EXO1 deletion avoids fork degradation in rad53 mutants, it does not suppress their sensitivity to the ribonucleotide reductase (RNR) inhibitor hydroxyurea (HU). In this case, the inability to restart stalled forks is likely to account for the lethality of rad53 mutant cells after replication blocks. Here we show that Rad53 regulates replication restart through the checkpoint-dependent transcriptional response, and more specifically, through RNR induction. Thus, in addition to preventing fork degradation, Rad53 prevents cell death in the presence of HU by regulating RNR-expression and localization. When RNR is induced in the absence of Exo1 and RNR negative regulators, cell viability of rad53 mutants treated with HU is increased and the ability of replication forks to restart after replicative stress is restored.

TET1-Mediated Hydroxymethylation Facilitates Hypoxic Gene Induction in Neuroblastoma

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Christopher J. Mariani

2014-06-01

Full Text Available The ten-eleven-translocation 5-methylcytosine dioxygenase (TET family of enzymes catalyzes the conversion of 5-methylcytosine (5-mC to 5-hydroxymethylcytosine (5-hmC, a modified cytosine base that facilitates gene expression. Cells respond to hypoxia by inducing a transcriptional program regulated in part by oxygen-dependent dioxygenases that require Fe(II and α-ketoglutarate. Given that the TET enzymes also require these cofactors, we hypothesized that the TETs regulate the hypoxia-induced transcriptional program. Here, we demonstrate that hypoxia increases global 5-hmC levels, with accumulation of 5-hmC density at canonical hypoxia response genes. A subset of 5-hmC gains colocalize with hypoxia response elements facilitating DNA demethylation and HIF binding. Hypoxia results in transcriptional activation of TET1, and full induction of hypoxia-responsive genes and global 5-hmC increases require TET1. Finally, we show that 5-hmC increases and TET1 upregulation in hypoxia are HIF-1 dependent. These findings establish TET1-mediated 5-hmC changes as an important epigenetic component of the hypoxic response.

Gene expression profiling in the inductive human hematopoietic microenvironment

International Nuclear Information System (INIS)

Zhao Yongjun; Chen, Edwin; Li Liheng; Gong Baiwei; Xie Wei; Nanji, Shaherose; Dube, Ian D.; Hough, Margaret R.

2004-01-01

Human hematopoietic stem cells (HSCs) and their progenitors can be maintained in vitro in long-term bone marrow cultures (LTBMCs) in which constituent HSCs can persist within the adherent layers for up to 2 months. Media replenishment of LTBMCs has been shown to induce transition of HSCs from a quiescent state to an active cycling state. We hypothesize that the media replenishment of the LTBMCs leads to the activation of important regulatory genes uniquely involved in HSC proliferation and differentiation. To profile the gene expression changes associated with HSC activation, we performed suppression subtractive hybridization (SSH) on day 14 human LTBMCs following 1-h media replenishment and on unmanipulated controls. The generated SSH library contained 191 differentially up-regulated expressed sequence tags (ESTs), the majority corresponding to known genes related to various intracellular processes, including signal transduction pathways, protein synthesis, and cell cycle regulation. Nineteen ESTs represented previously undescribed sequences encoding proteins of unknown function. Differential up-regulation of representative genes, including IL-8, IL-1, putative cytokine 21/HC21, MAD3, and a novel EST was confirmed by semi-quantitative RT-PCR. Levels of fibronectin, G-CSF, and stem cell factor also increased in the conditioned media of LTBMCs as assessed by ELISA, indicating increased synthesis and secretion of these factors. Analysis of our library provides insights into some of the immediate early gene changes underlying the mechanisms by which the stromal elements within the LTBMCs contribute to the induction of HSC activation and provides the opportunity to identify as yet unrecognized factors regulating HSC activation in the LTBMC milieu

Expression profiling of AUXIN RESPONSE FACTOR genes during somatic embryogenesis induction in Arabidopsis.

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Wójcikowska, Barbara; Gaj, Małgorzata D

2017-06-01

Extensive modulation of numerous ARF transcripts in the embryogenic culture of Arabidopsis indicates a substantial role of auxin signaling in the mechanism of somatic embryogenesis induction. Somatic embryogenesis (SE) is induced by auxin in plants and auxin signaling is considered to play a key role in the molecular mechanism that controls the embryogenic transition of plant somatic cells. Accordingly, the expression of AUXIN RESPONSE FACTOR (ARF) genes in embryogenic culture of Arabidopsis was analyzed. The study revealed that 14 of the 22 ARFs were transcribed during SE in Arabidopsis. RT-qPCR analysis indicated that the expression of six ARFs (ARF5, ARF6, ARF8, ARF10, ARF16, and ARF17) was significantly up-regulated, whereas five other genes (ARF1, ARF2, ARF3, ARF11, and ARF18) were substantially down-regulated in the SE-induced explants. The activity of ARFs during SE was also monitored with GFP reporter lines and the ARFs that were expressed in areas of the explants engaged in SE induction were detected. A functional test of ARFs transcribed during SE was performed and the embryogenic potential of the arf mutants and overexpressor lines was evaluated. ARFs with a significantly modulated expression during SE coupled with an impaired embryogenic response of the relevant mutant and/or overexpressor line, including ARF1, ARF2, ARF3, ARF5, ARF6, ARF8, and ARF11 were indicated as possibly being involved in SE induction. The study provides evidence that embryogenic induction strongly depends on ARFs, which are key regulators of the auxin signaling. Some clues on the possible functions of the candidate ARFs, especially ARF5, in the mechanism of embryogenic transition are discussed. The results provide guidelines for further research on the auxin-related functional genomics of SE and the developmental plasticity of somatic cells.

The Escherichia coli Cpx envelope stress response regulates genes of diverse function that impact antibiotic resistance and membrane integrity.

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Raivio, Tracy L; Leblanc, Shannon K D; Price, Nancy L

2013-06-01

The Cpx envelope stress response mediates adaptation to stresses that cause envelope protein misfolding. Adaptation is partly conferred through increased expression of protein folding and degradation factors. The Cpx response also plays a conserved role in the regulation of virulence determinant expression and impacts antibiotic resistance. We sought to identify adaptive mechanisms that may be involved in these important functions by characterizing changes in the transcriptome of two different Escherichia coli strains when the Cpx response is induced. We show that, while there is considerable strain- and condition-specific variability in the Cpx response, the regulon is enriched for proteins and functions that are inner membrane associated under all conditions. Genes that were changed by Cpx pathway induction under all conditions were involved in a number of cellular functions and included several intergenic regions, suggesting that posttranscriptional regulation is important during Cpx-mediated adaptation. Some Cpx-regulated genes are centrally involved in energetics and play a role in antibiotic resistance. We show that a number of small, uncharacterized envelope proteins are Cpx regulated and at least two of these affect phenotypes associated with membrane integrity. Altogether, our work suggests new mechanisms of Cpx-mediated envelope stress adaptation and antibiotic resistance.

Transcriptome analysis uncovers Arabidopsis F-BOX STRESS INDUCED 1 as a regulator of jasmonic acid and abscisic acid stress gene expression.

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Gonzalez, Lauren E; Keller, Kristen; Chan, Karen X; Gessel, Megan M; Thines, Bryan C

2017-07-17

The ubiquitin 26S proteasome system (UPS) selectively degrades cellular proteins, which results in physiological changes to eukaryotic cells. F-box proteins are substrate adaptors within the UPS and are responsible for the diversity of potential protein targets. Plant genomes are enriched in F-box genes, but the vast majority of these have unknown roles. This work investigated the Arabidopsis F-box gene F-BOX STRESS INDUCED 1 (FBS1) for its effects on gene expression in order elucidate its previously unknown biological function. Using publically available Affymetrix ATH1 microarray data, we show that FBS1 is significantly co-expressed in abiotic stresses with other well-characterized stress response genes, including important stress-related transcriptional regulators. This gene suite is most highly expressed in roots under cold and salt stresses. Transcriptome analysis of fbs1-1 knock-out plants grown at a chilling temperature shows that hundreds of genes require FBS1 for appropriate expression, and that these genes are enriched in those having roles in both abiotic and biotic stress responses. Based on both this genome-wide expression data set and quantitative real-time PCR (qPCR) analysis, it is apparent that FBS1 is required for elevated expression of many jasmonic acid (JA) genes that have established roles in combatting environmental stresses, and that it also controls a subset of JA biosynthesis genes. FBS1 also significantly impacts abscisic acid (ABA) regulated genes, but this interaction is more complex, as FBS1 has both positive and negative effects on ABA-inducible and ABA-repressible gene modules. One noteworthy effect of FBS1 on ABA-related stress processes, however, is the restraint it imposes on the expression of multiple class I LIPID TRANSFER PROTEIN (LTP) gene family members that have demonstrated protective effects in water deficit-related stresses. FBS1 impacts plant stress responses by regulating hundreds of genes that respond to the plant

Transcriptomic events involved in melon mature-fruit abscission comprise the sequential induction of cell-wall degrading genes coupled to a stimulation of endo and exocytosis.

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Jorge Corbacho

Full Text Available Mature-fruit abscission (MFA in fleshy-fruit is a genetically controlled process with mechanisms that, contrary to immature-fruit abscission, has not been fully characterized. Here, we use pyrosequencing to characterize the transcriptomes of melon abscission zone (AZ at three stages during AZ-cell separation in order to understand MFA control at an early stage of AZ-activation.The results show that by early induction of MFA, the melon AZ exhibits major gene induction, while by late induction of MFA, melon AZ shows major gene repression. Although some genes displayed similar regulation in both early and late induction of abscission, such as EXT1-EXT4, EGase1, IAA2, ERF1, AP2D15, FLC, MADS2, ERAF17, SAP5 and SCL13 genes, the majority had different expression patterns. This implies that time-specific events occur during MFA, and emphasizes the value of characterizing multiple time-specific abscission transcriptomes. Analysis of gene-expression from these AZs reveal that a sequential induction of cell-wall-degrading genes is associated with the upregulation of genes involved in endo and exocytosis, and a shift in plant-hormone metabolism and signaling genes during MFA. This is accompanied by transcriptional activity of small-GTPases and synthaxins together with tubulins, dynamins, V-type ATPases and kinesin-like proteins potentially involved in MFA signaling. Early events are potentially controlled by down-regulation of MADS-box, AP2/ERF and Aux/IAA transcription-factors, and up-regulation of homeobox, zinc finger, bZIP, and WRKY transcription-factors, while late events may be controlled by up-regulation of MYB transcription-factors.Overall, the data provide a comprehensive view on MFA in fleshy-fruit, identifying candidate genes and pathways associated with early induction of MFA. Our comprehensive gene-expression profile will be very useful for elucidating gene regulatory networks of the MFA in fleshy-fruit.

Gene expression profiling in the stress control brain region hypothalamic paraventricular nucleus reveals a novel gene network including Amyloid beta Precursor Protein

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Deussing Jan M

2010-10-01

Full Text Available Abstract Background The pivotal role of stress in the precipitation of psychiatric diseases such as depression is generally accepted. This study aims at the identification of genes that are directly or indirectly responding to stress. Inbred mouse strains that had been evidenced to differ in their stress response as well as in their response to antidepressant treatment were chosen for RNA profiling after stress exposure. Gene expression and regulation was determined by microarray analyses and further evaluated by bioinformatics tools including pathway and cluster analyses. Results Forced swimming as acute stressor was applied to C57BL/6J and DBA/2J mice and resulted in sets of regulated genes in the paraventricular nucleus of the hypothalamus (PVN, 4 h or 8 h after stress. Although the expression changes between the mouse strains were quite different, they unfolded in phases over time in both strains. Our search for connections between the regulated genes resulted in potential novel signalling pathways in stress. In particular, Guanine nucleotide binding protein, alpha inhibiting 2 (GNAi2 and Amyloid β (A4 precursor protein (APP were detected as stress-regulated genes, and together with other genes, seem to be integrated into stress-responsive pathways and gene networks in the PVN. Conclusions This search for stress-regulated genes in the PVN revealed its impact on interesting genes (GNAi2 and APP and a novel gene network. In particular the expression of APP in the PVN that is governing stress hormone balance, is of great interest. The reported neuroprotective role of this molecule in the CNS supports the idea that a short acute stress can elicit positive adaptational effects in the brain.

Ammonia stress under high environmental ammonia induces Hsp70 and Hsp90 in the mud eel, Monopterus cuchia.

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Hangzo, Hnunlalliani; Banerjee, Bodhisattwa; Saha, Shrabani; Saha, Nirmalendu

2017-02-01

The obligatory air-breathing mud eel (Monopterus cuchia) is frequently being challenged with high environmental ammonia (HEA) exposure in its natural habitats. The present study investigated the possible induction of heat shock protein 70 and 90 (hsp70, hsc70, hsp90α and hsp90β) genes and more expression of Hsp70 and Hsp90 proteins under ammonia stress in different tissues of the mud eel after exposure to HEA (50 mM NH 4 Cl) for 14 days. HEA resulted in significant accumulation of toxic ammonia in different body tissues and plasma, which was accompanied with the stimulation of oxidative stress in the mud eel as evidenced by more accumulation of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ) during exposure to HEA. Further, hyper-ammonia stress led to significant increase in the levels of mRNA transcripts for inducible hsp70 and hsp90α genes and also their translated proteins in different tissues probably as a consequence of induction of hsp70 and hsp90α genes in the mud eel. However, hyper-ammonia stress was neither associated with any significant alterations in the levels of mRNA transcripts for constitutive hsc70 and hsp90β genes nor their translated proteins in any of the tissues studied. More abundance of Hsp70 and Hsp90α proteins might be one of the strategies adopted by the mud eel to defend itself from the ammonia-induced cellular damages under ammonia stress. Further, this is the first report of ammonia-induced induction of hsp70 and hsp90α genes under hyper-ammonia stress in any freshwater air-breathing teleost.

Distinct steps of neural induction revealed by Asterix, Obelix and TrkC, genes induced by different signals from the organizer.

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Sonia Pinho

2011-04-01

Full Text Available The amniote organizer (Hensen's node can induce a complete nervous system when grafted into a peripheral region of a host embryo. Although BMP inhibition has been implicated in neural induction, non-neural cells cannot respond to BMP antagonists unless previously exposed to a node graft for at least 5 hours before BMP inhibitors. To define signals and responses during the first 5 hours of node signals, a differential screen was conducted. Here we describe three early response genes: two of them, Asterix and Obelix, encode previously undescribed proteins of unknown function but Obelix appears to be a nuclear RNA-binding protein. The third is TrkC, a neurotrophin receptor. All three genes are induced by a node graft within 4-5 hours but they differ in the extent to which they are inducible by FGF: FGF is both necessary and sufficient to induce Asterix, sufficient but not necessary to induce Obelix and neither sufficient nor necessary for induction of TrkC. These genes are also not induced by retinoic acid, Noggin, Chordin, Dkk1, Cerberus, HGF/SF, Somatostatin or ionomycin-mediated Calcium entry. Comparison of the expression and regulation of these genes with other early neural markers reveals three distinct "epochs", or temporal waves, of gene expression accompanying neural induction by a grafted organizer, which are mirrored by specific stages of normal neural plate development. The results are consistent with neural induction being a cascade of responses elicited by different signals, culminating in the formation of a patterned nervous system.

Clock genes × stress × reward interactions in alcohol and substance use disorders.

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Perreau-Lenz, Stéphanie; Spanagel, Rainer

2015-06-01

Adverse life events and highly stressful environments have deleterious consequences for mental health. Those environmental factors can potentiate alcohol and drug abuse in vulnerable individuals carrying specific genetic risk factors, hence producing the final risk for alcohol- and substance-use disorders development. The nature of these genes remains to be fully determined, but studies indicate their direct or indirect relation to the stress hypothalamo-pituitary-adrenal (HPA) axis and/or reward systems. Over the past decade, clock genes have been revealed to be key-players in influencing acute and chronic alcohol/drug effects. In parallel, the influence of chronic stress and stressful life events in promoting alcohol and substance use and abuse has been demonstrated. Furthermore, the reciprocal interaction of clock genes with various HPA-axis components, as well as the evidence for an implication of clock genes in stress-induced alcohol abuse, have led to the idea that clock genes, and Period genes in particular, may represent key genetic factors to consider when examining gene × environment interaction in the etiology of addiction. The aim of the present review is to summarize findings linking clock genes, stress, and alcohol and substance abuse, and to propose potential underlying neurobiological mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

Heme oxygenase-1 induction improves cardiac function following myocardial ischemia by reducing oxidative stress.

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Yossi Issan

Full Text Available Oxidative stress plays a key role in exacerbating diabetes and cardiovascular disease. Heme oxygenase-1 (HO-1, a stress response protein, is cytoprotective, but its role in post myocardial infarction (MI and diabetes is not fully characterized. We aimed to investigate the protection and the mechanisms of HO-1 induction in cardiomyocytes subjected to hypoxia and in diabetic mice subjected to LAD ligation.In vitro: cultured cardiomyocytes were treated with cobalt-protoporphyrin (CoPP and tin protoporphyrin (SnPP prior to hypoxic stress. In vivo: CoPP treated streptozotocin-induced diabetic mice were subjected to LAD ligation for 2/24 h. Cardiac function, histology, biochemical damage markers and signaling pathways were measured.HO-1 induction lowered release of lactate dehydrogenase (LDH and creatine phospho kinase (CK, decreased propidium iodide staining, improved cell morphology and preserved mitochondrial membrane potential in cardiomyocytes. In diabetic mice, Fractional Shortening (FS was lower than non-diabetic mice (35±1%vs.41±2, respectively p<0.05. CoPP-treated diabetic animals improved cardiac function (43±2% p<0.01, reduced CK, Troponin T levels and infarct size compared to non-treated diabetic mice (P<0.01, P<0.001, P<0.01 respectively. CoPP-enhanced HO-1 protein levels and reduced oxidative stress in diabetic animals, as indicated by the decrease in superoxide levels in cardiac tissues and plasma TNFα levels (p<0.05. The increased levels of HO-1 by CoPP treatment after LAD ligation led to a shift of the Bcl-2/bax ratio towards the antiapoptotic process (p<0.05. CoPP significantly increased the expression levels of pAKT and pGSK3β (p<0.05 in cardiomyocytes and in diabetic mice with MI. SnPP abolished CoPP's cardioprotective effects.HO-1 induction plays a role in cardioprotection against hypoxic damage in cardiomyocytes and in reducing post ischemic cardiac damage in the diabetic heart as proved by the increased levels of pAKT with

Environmental stress, oxytocin receptor gene (OXTR) polymorphism, and mental health following collective stress

OpenAIRE

Lucas-Thompson, RG; Holman, EA

2013-01-01

We examined whether the oxytocin receptor gene (OXTR) single nucleotide polymorphism (SNP) rs53576 genotype buffers the combined impact of negative social environments (e.g., interpersonal conflict/constraint) and economic stress on post-traumatic stress (PTS) symptoms and impaired daily functioning following collective stress (September 11th terrorist attacks). Saliva was collected by mail and used to genotype 704 respondents. Participants completed Web-based assessments of pre-9/11 mental h...

The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis

KAUST Repository

Wang, Zhenyu

2011-05-01

Osmotic stress activates the biosynthesis of abscisic acid (ABA). One major step in ABA biosynthesis is the carotenoid cleavage catalyzed by a 9-cis epoxycarotenoid dioxygenase (NCED). To understand the mechanism for osmotic stress activation of ABA biosynthesis, we screened for Arabidopsis thaliana mutants that failed to induce the NCED3 genee xpression in response to osmotic stress treatments. The ced1 (for 9-cis epoxycarotenoid dioxy genase defective 1) mutant isolated in this study showed markedly reduced expression of NCED3 in response to osmotic stress (polyethylene glycol)treatments compared with the wild type. Other ABA biosynthesis genes are also greatly reduced in ced1 under osmotic stress. ced1 mutant plants are very sensitive to even mild osmotic stress. Map-based cloning revealed unexpectedly thatCED1 encodes a putative a/b hydrolase domain-containing protein and is allelic to the BODYGUARD gene that was recently shown to be essential for cuticle biogenesis. Further studies discovered that other cut in biosynthesis mutants are also impaired in osmotic stress induction of ABA biosynthesis genes and are sensitive to osmotic stress. Our work demonstrates that the cuticle functions not merely as a physical barrier to minimize water loss but also mediates osmotic stress signaling and tolerance by regulating ABA biosynthesis and signaling. © 2011 American Society of Plant Biologists. All rights reserved.

Chicken domestication changes expression of stress-related genes in brain, pituitary and adrenals

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Pia Løtvedt

2017-12-01

Full Text Available Domesticated species have an attenuated behavioral and physiological stress response compared to their wild counterparts, but the genetic mechanisms underlying this change are not fully understood. We investigated gene expression of a panel of stress response-related genes in five tissues known for their involvement in the stress response: hippocampus, hypothalamus, pituitary, adrenal glands and liver of domesticated White Leghorn chickens and compared it with the wild ancestor of all domesticated breeds, the Red Junglefowl. Gene expression was measured both at baseline and after 45 min of restraint stress. Most of the changes in gene expression related to stress were similar to mammals, with an upregulation of genes such as FKBP5, C-FOS and EGR1 in hippocampus and hypothalamus and StAR, MC2R and TH in adrenal glands. We also found a decrease in the expression of CRHR1 in the pituitary of chickens after stress, which could be involved in negative feedback regulation of the stress response. Furthermore, we observed a downregulation of EGR1 and C-FOS in the pituitary following stress, which could be a potential link between stress and its effects on reproduction and growth in chickens.We also found changes in the expression of important genes between breeds such as GR in the hypothalamus, POMC and PC1 in the pituitary and CYP11A1 and HSD3B2 in the adrenal glands. These results suggest that the domesticated White Leghorn may have a higher capacity for negative feedback of the HPA axis, a lower capacity for synthesis of ACTH in the pituitary and a reduced synthesis rate of corticosterone in the adrenal glands compared to Red Junglefowl. All of these findings could explain the attenuated stress response in the domesticated birds. Keywords: Animal domestication, Stress response, HPA axis, Glucocorticoid receptor, Gene expression, Chicken

Psychological Stress, Cocaine and Natural Reward Each Induce Endoplasmic Reticulum Stress Genes in Rat Brain

OpenAIRE

Pavlovsky, Ashly A.; Boehning, Darren; Li, Dingge; Zhang, Yafang; Fan, Xiuzhen; Green, Thomas A.

2013-01-01

Our prior research has shown that the transcription of endoplasmic reticulum (ER) stress transcription factors Activating Transcription Factor 3 (ATF3) and ATF4 are induced by amphetamine and restraint stress in rat striatum. However, presently it is unknown the full extent of ER stress responses to psychological stress or cocaine, and which of the three ER stress pathways is activated. The current study examines transcriptional responses of key ER stress target genes subsequent to psychologi...

Resveratrol inhibits LXRα-dependent hepatic lipogenesis through novel antioxidant Sestrin2 gene induction

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Jin, So Hee; Yang, Ji Hye; Shin, Bo Yeon; Seo, Kyuhwa; Shin, Sang Mi [College of Pharmacy, Chosun University, Gwangju 501-759 (Korea, Republic of); Cho, Il Je, E-mail: skek023@dhu.ac.kr [MRC-GHF, College of Korean Medicine, Daegu Haany University, Gyeongsan, Gyeongsangbukdo 712-715 (Korea, Republic of); Ki, Sung Hwan, E-mail: shki@chosun.ac.kr [College of Pharmacy, Chosun University, Gwangju 501-759 (Korea, Republic of)

2013-08-15

Liver X receptor-α (LXRα), a member of the nuclear receptor superfamily of ligand-activated transcription factors, regulates de novo fatty acid synthesis that leads to stimulate hepatic steatosis. Although, resveratrol has beneficial effects on metabolic disease, it is not known whether resveratrol affects LXRα-dependent lipogenic gene expression. This study investigated the effect of resveratrol in LXRα-mediated lipogenesis and the underlying molecular mechanism. Resveratrol inhibited the ability of LXRα to activate sterol regulatory element binding protein-1c (SREBP-1c) and thereby inhibited target gene expression in hepatocytes. Moreover, resveratrol decreased LXRα–RXRα DNA binding activity and LXRE-luciferase transactivation. Resveratrol is known to activate Sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK), although its precise mechanism of action remains controversial. We found that the ability of resveratrol to repress T0901317-induced SREBP-1c expression was not dependent on AMPK and Sirt1. It is well established that hepatic steatosis is associated with antioxidant and redox signaling. Our data showing that expression of Sestrin2 (Sesn2), which is a novel antioxidant gene, was significantly down-regulated in the livers of high-fat diet-fed mice. Moreover, resveratrol up-regulated Sesn2 expression, but not Sesn1 and Sesn3. Sesn2 overexpression repressed LXRα-activated SREBP-1c expression and LXRE-luciferase activity. Finally, Sesn2 knockdown using siRNA abolished the effect of resveratrol in LXRα-induced FAS luciferase gene transactivation. We conclude that resveratrol affects Sesn2 gene induction and contributes to the inhibition of LXRα-mediated hepatic lipogenesis. - Highlights: • We investigated the effect of resveratrol in LXRα-mediated lipogenesis. • Resveratrol attenuated the ability of the LXRα-mediated lipogenic gene expression. • Resveratrol’s effects on T090-induced lipogenesis is not dependent on Sirt1 or AMPK. �

Resveratrol inhibits LXRα-dependent hepatic lipogenesis through novel antioxidant Sestrin2 gene induction

International Nuclear Information System (INIS)

Jin, So Hee; Yang, Ji Hye; Shin, Bo Yeon; Seo, Kyuhwa; Shin, Sang Mi; Cho, Il Je; Ki, Sung Hwan

2013-01-01

Liver X receptor-α (LXRα), a member of the nuclear receptor superfamily of ligand-activated transcription factors, regulates de novo fatty acid synthesis that leads to stimulate hepatic steatosis. Although, resveratrol has beneficial effects on metabolic disease, it is not known whether resveratrol affects LXRα-dependent lipogenic gene expression. This study investigated the effect of resveratrol in LXRα-mediated lipogenesis and the underlying molecular mechanism. Resveratrol inhibited the ability of LXRα to activate sterol regulatory element binding protein-1c (SREBP-1c) and thereby inhibited target gene expression in hepatocytes. Moreover, resveratrol decreased LXRα–RXRα DNA binding activity and LXRE-luciferase transactivation. Resveratrol is known to activate Sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK), although its precise mechanism of action remains controversial. We found that the ability of resveratrol to repress T0901317-induced SREBP-1c expression was not dependent on AMPK and Sirt1. It is well established that hepatic steatosis is associated with antioxidant and redox signaling. Our data showing that expression of Sestrin2 (Sesn2), which is a novel antioxidant gene, was significantly down-regulated in the livers of high-fat diet-fed mice. Moreover, resveratrol up-regulated Sesn2 expression, but not Sesn1 and Sesn3. Sesn2 overexpression repressed LXRα-activated SREBP-1c expression and LXRE-luciferase activity. Finally, Sesn2 knockdown using siRNA abolished the effect of resveratrol in LXRα-induced FAS luciferase gene transactivation. We conclude that resveratrol affects Sesn2 gene induction and contributes to the inhibition of LXRα-mediated hepatic lipogenesis. - Highlights: • We investigated the effect of resveratrol in LXRα-mediated lipogenesis. • Resveratrol attenuated the ability of the LXRα-mediated lipogenic gene expression. • Resveratrol’s effects on T090-induced lipogenesis is not dependent on Sirt1 or AMPK. �

Impact of Heat Stress on Cellular and Transcriptional Adaptation of Mammary Epithelial Cells in Riverine Buffalo (Bubalus Bubalis).

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Kapila, Neha; Sharma, Ankita; Kishore, Amit; Sodhi, Monika; Tripathi, Pawan K; Mohanty, Ashok K; Mukesh, Manishi

2016-01-01

The present study aims to identify the heat responsive genes and biological pathways in heat stressed buffalo mammary epithelial cells (MECs). The primary mammary epithelial cells of riverine buffalo were exposed to thermal stress at 42°C for one hour. The cells were subsequently allowed to recover at 37°C and harvested at different time intervals (30 min to 48 h) along with control samples (un-stressed). In order to assess the impact of heat stress in buffalo MECs, several in-vitro cellular parameters (lactate dehydrogenase activity, cell proliferation assay, cellular viability, cell death and apoptosis) and transcriptional studies were conducted. The heat stress resulted in overall decrease in cell viability and cell proliferation of MECs while induction of cellular apoptosis and necrosis. The transcriptomic profile of heat stressed MECs was generated using Agilent 44 K bovine oligonucleotide array and at cutoff criteria of ≥3-or ≤3 fold change, a total of 153 genes were observed to be upregulated while 8 genes were down regulated across all time points post heat stress. The genes that were specifically up-regulated or down-regulated were identified as heat responsive genes. The upregulated genes in heat stressed MECs belonged to heat shock family viz., HSPA6, HSPB8, DNAJB2, HSPA1A. Along with HSPs, genes like BOLA, MRPL55, PFKFB3, PSMC2, ENDODD1, ARID5A, and SENP3 were also upregulated. Microarray data revealed that the heat responsive genes belonged to different functional classes viz., chaperons; immune responsive; cell proliferation and metabolism related. Gene ontology analysis revealed enrichment of several biological processes like; cellular process, metabolic process, response to stimulus, biological regulation, immune system processes and signaling. The transcriptome analysis data was further validated by RT-qPCR studies. Several HSP (HSP40, HSP60, HSP70, HSP90, and HSPB1), apoptotic (Bax and Bcl2), immune (IL6, TNFα and NF-kβ) and oxidative

Deletion analysis of Streptococcus pneumoniae late competence genes distinguishes virulence determinants that are dependent or independent of competence induction.

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Zhu, Luchang; Lin, Jingjun; Kuang, Zhizhou; Vidal, Jorge E; Lau, Gee W

2015-07-01

The competence regulon of Streptococcus pneumoniae (pneumococcus) is crucial for genetic transformation. During competence development, the alternative sigma factor ComX is activated, which in turn, initiates transcription of 80 'late' competence genes. Interestingly, only 16 late genes are essential for genetic transformation. We hypothesized that these late genes that are dispensable for competence are beneficial to pneumococcal fitness during infection. These late genes were systematically deleted, and the resulting mutants were examined for their fitness during mouse models of bacteremia and acute pneumonia. Among these, 14 late genes were important for fitness in mice. Significantly, deletion of some late genes attenuated pneumococcal fitness to the same level in both wild-type and ComX-null genetic backgrounds, suggesting that the constitutive baseline expression of these genes was important for bacterial fitness. In contrast, some mutants were attenuated only in the wild-type genetic background but not in the ComX-null background, suggesting that specific expression of these genes during competence state contributed to pneumococcal fitness. Increased virulence during competence state was partially caused by the induction of allolytic enzymes that enhanced pneumolysin release. These results distinguish the role of basal expression versus competence induction in virulence functions encoded by ComX-regulated late competence genes. © 2015 John Wiley & Sons Ltd.

DNA damage and defence gene expression after oxidative stress induced by x-rays and diesel exhaust particles

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Risom, Lotte

2004-07-01

Particulate air pollution is one the most important environmental health factors for people living in cities. Especially the exhaust particles from traffic are possible causes for cancer and cardiopulmonary diseases. The aim of this thesis was to characterize the health effects of diesel exhaust particles (DEP) by inducing oxidative stress and analyse the underlying mechanisms. Methods for determining oxidative stress, DNA damage, and gene expression were validated and calibrated in lung tissue by studying the dose response relations after ionizing radiation. The study showed the feasibility of partial-body x-ray irradiation as an in vivo model for induction and repair of oxidative DNA damage, of DNA repair enzymes expression, and antioxidant defense genes. A 'nose-only' mouse model for inhalation of ultra-fine particles showed that particles induce oxidative DNA damage in lung tissue and in bronchoalveolar lavage cells. The exposure increased the expression of HO-1 mRNA and oxoguanine DNA glycosylase OGG1 mRNA. The levels of 8-oxodG and OGG1 mRNA were mirror images. Colon and liver were analysed after administration of DEP in the diet with or without increasing doses of sucrose. This study indicated that DEP induces DNA adducts and oxidative stress through formation of DNA strand breaks, DNA repair enzyme expression, apoptosis, and protein oxidisation in colon and liver at relatively low exposure doses. The thesis is based on four published journal articles. (ln)

DNA damage and defence gene expression after oxidative stress induced by x-rays and diesel exhaust particles

International Nuclear Information System (INIS)

Risom, Lotte

2004-01-01

Particulate air pollution is one the most important environmental health factors for people living in cities. Especially the exhaust particles from traffic are possible causes for cancer and cardiopulmonary diseases. The aim of this thesis was to characterize the health effects of diesel exhaust particles (DEP) by inducing oxidative stress and analyse the underlying mechanisms. Methods for determining oxidative stress, DNA damage, and gene expression were validated and calibrated in lung tissue by studying the dose response relations after ionizing radiation. The study showed the feasibility of partial-body x-ray irradiation as an in vivo model for induction and repair of oxidative DNA damage, of DNA repair enzymes expression, and antioxidant defense genes. A 'nose-only' mouse model for inhalation of ultra-fine particles showed that particles induce oxidative DNA damage in lung tissue and in bronchoalveolar lavage cells. The exposure increased the expression of HO-1 mRNA and oxoguanine DNA glycosylase OGG1 mRNA. The levels of 8-oxodG and OGG1 mRNA were mirror images. Colon and liver were analysed after administration of DEP in the diet with or without increasing doses of sucrose. This study indicated that DEP induces DNA adducts and oxidative stress through formation of DNA strand breaks, DNA repair enzyme expression, apoptosis, and protein oxidisation in colon and liver at relatively low exposure doses. The thesis is based on four published journal articles. (ln)

Aluminium resistant, plant growth promoting bacteria induce overexpression of Aluminium stress related genes in Arabidopsis thaliana and increase the ginseng tolerance against Aluminium stress.

Science.gov (United States)

Farh, Mohamed El-Agamy; Kim, Yeon-Ju; Sukweenadhi, Johan; Singh, Priyanka; Yang, Deok-Chun

2017-07-01

Panax ginseng is an important cash crop in the Asian countries due to its pharmaceutical effects, however the plant is exposed to various abiotic stresses, lead to reduction of its quality. One of them is the Aluminum (Al) accumulation. Plant growth promoting bacteria which able to tolerate heavy metals has been considered as a new trend for supporting the growth of many crops in heavy metal occupied areas. In this study, twelve bacteria strains were isolated from rhizosphere of diseased Korean ginseng roots located in Gochang province, Republic of Korea and tested for their ability to grow in Al-embedded broth media. Out of them, four strains (Pseudomonas simiae N3, Pseudomonas fragi N8, Chryseobacterium polytrichastri N10, and Burkholderia ginsengiterrae N11-2) were able to grow. The strains could also show other plant growth promoting activities e.g. auxins and siderophores production and phosphate solubilization. P. simiae N3, C. polytrichastri N10, and B. ginsengiterrae N11-2 strains were able to support the growth of Arabidopsis thaliana stressed by Al while P. fragi N8 could not. Plants inoculated with P. simiae N3, C. polytrichastri N10, and B. ginsengiterrae N11-2 showed higher expression level of Al-stress related genes, AtAIP, AtALS3 and AtALMT1, compared to non-bacterized plants. Expression profiles of the genes reveal the induction of external mechanism of Al resistance by P. simiae N3 and B. ginsengiterrae N11-2 and internal mechanism by C. polytrichastri N10. Korean ginseng seedlings treated with these strains showed higher biomass, particularly the foliar part, higher chlorophyll content than non-bacterized Al-stressed seedlings. According to the present results, these strains can be used in the future for the cultivation of ginseng in Al-persisted locations. Copyright © 2017 Elsevier GmbH. All rights reserved.

Selection of reliable reference genes for gene expression studies in Trichoderma afroharzianum LTR-2 under oxalic acid stress.

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Lyu, Yuping; Wu, Xiaoqing; Ren, He; Zhou, Fangyuan; Zhou, Hongzi; Zhang, Xinjian; Yang, Hetong

2017-10-01

An appropriate reference gene is required to get reliable results from gene expression analysis by quantitative real-time reverse transcription PCR (qRT-PCR). In order to identify stable and reliable reference genes in Trichoderma afroharzianum under oxalic acid (OA) stress, six commonly used housekeeping genes, i.e., elongation factor 1, ubiquitin, ubiquitin-conjugating enzyme, glyceraldehyde-3-phosphate dehydrogenase, α-tubulin, actin, from the effective biocontrol isolate T. afroharzianum strain LTR-2 were tested for their expression during growth in liquid culture amended with OA. Four in silico programs (comparative ΔCt, NormFinder, geNorm and BestKeeper) were used to evaluate the expression stabilities of six candidate reference genes. The elongation factor 1 gene EF-1 was identified as the most stably expressed reference gene, and was used as the normalizer to quantify the expression level of the oxalate decarboxylase coding gene OXDC in T. afroharzianum strain LTR-2 under OA stress. The result showed that the expression of OXDC was significantly up-regulated as expected. This study provides an effective method to quantify expression changes of target genes in T. afroharzianum under OA stress. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of salt-stress induced differentially expressed genes in ...

African Journals Online (AJOL)

Identification of salt-stress induced differentially expressed genes in barley leaves using the annealingcontrol- primer-based GeneFishing technique. S Lee, K Lee, K Kim, GJ Choi, SH Yoon, HC Ji, S Seo, YC Lim, N Ahsan ...

Molecular Cloning and mRNA Expression of Heat Shock Protein Genes and Their Response to Cadmium Stress in the Grasshopper Oxya chinensis.

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Yuping Zhang

Full Text Available Heat shock proteins (Hsps are highly conserved molecular chaperones that are synthesized in response to stress. In this study, we cloned the full-length sequences of the Grp78 (glucose-regulated protein 78, Hsp70, Hsp90, and Hsp40 genes from the Chinese rice grasshopper Oxya chinensis. The full-length cDNA sequences of OcGrp78, OcHsp70, OcHsp90, and OcHsp40 contain open reading frames of 1947, 1920, 2172, and 1042 bp that encode proteins of 649, 640, 724, and 347 amino acids, respectively. Fluorescent real-time quantitative PCR (RT-qPCR was performed to quantify the relative transcript levels of these Hsp genes in different tissues and developmental stages. The mRNAs encoding these four Hsp genes were present at all developmental stages and in all tissues examined but were expressed at varying levels. Additionally, we investigated the mRNA expression profiles of these four Hsps in O. chinensis subjected to Cadmium (Cd stress. OcGrp78, OcHsp70, OcHsp90, and OcHsp40 mRNA expression was induced under acute Cd stress; the levels reached a maximum within a short time (6 h, were reduced significantly at 12 h, and were lowered to or below control levels by 48 h. Regarding induction efficiency, OcHsp70 was the most sensitive gene to acute Cd stress. Chronic Cd exposure showed that dietary Cd treatment induced increased OcGrp78, OcHsp90, and OcHsp40 expression. However, dietary Cd induced a significant reduction of OcHsp70 expression. In the period tested, no significant difference in the mortality of the grasshoppers was observed. Our results suggest that these four Hsps genes, especially OcHsp70, are sensitive to acute Cd stress and could be used as molecular markers for toxicology studies. However, our results also indicate that OcHsp70 is not suitable for use as a molecular marker of chronic Cd contamination.

Molecular Cloning and mRNA Expression of Heat Shock Protein Genes and Their Response to Cadmium Stress in the Grasshopper Oxya chinensis.

Science.gov (United States)

Zhang, Yuping; Liu, Yaoming; Zhang, Jianzhen; Guo, Yaping; Ma, Enbo

2015-01-01

Heat shock proteins (Hsps) are highly conserved molecular chaperones that are synthesized in response to stress. In this study, we cloned the full-length sequences of the Grp78 (glucose-regulated protein 78), Hsp70, Hsp90, and Hsp40 genes from the Chinese rice grasshopper Oxya chinensis. The full-length cDNA sequences of OcGrp78, OcHsp70, OcHsp90, and OcHsp40 contain open reading frames of 1947, 1920, 2172, and 1042 bp that encode proteins of 649, 640, 724, and 347 amino acids, respectively. Fluorescent real-time quantitative PCR (RT-qPCR) was performed to quantify the relative transcript levels of these Hsp genes in different tissues and developmental stages. The mRNAs encoding these four Hsp genes were present at all developmental stages and in all tissues examined but were expressed at varying levels. Additionally, we investigated the mRNA expression profiles of these four Hsps in O. chinensis subjected to Cadmium (Cd) stress. OcGrp78, OcHsp70, OcHsp90, and OcHsp40 mRNA expression was induced under acute Cd stress; the levels reached a maximum within a short time (6 h), were reduced significantly at 12 h, and were lowered to or below control levels by 48 h. Regarding induction efficiency, OcHsp70 was the most sensitive gene to acute Cd stress. Chronic Cd exposure showed that dietary Cd treatment induced increased OcGrp78, OcHsp90, and OcHsp40 expression. However, dietary Cd induced a significant reduction of OcHsp70 expression. In the period tested, no significant difference in the mortality of the grasshoppers was observed. Our results suggest that these four Hsps genes, especially OcHsp70, are sensitive to acute Cd stress and could be used as molecular markers for toxicology studies. However, our results also indicate that OcHsp70 is not suitable for use as a molecular marker of chronic Cd contamination.

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

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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

Exploring valid internal-control genes in Porphyra yezoensis (Bangiaceae) during stress response conditions

Science.gov (United States)

Wang, Wenlei; Wu, Xiaojie; Wang, Chao; Jia, Zhaojun; He, Linwen; Wei, Yifan; Niu, Jianfeng; Wang, Guangce

2014-07-01

To screen the stable expression genes related to the stress (strong light, dehydration and temperature shock) we applied Absolute real-time PCR technology to determine the transcription numbers of the selected test genes in P orphyra yezoensis, which has been regarded as a potential model species responding the stress conditions in the intertidal. Absolute real-time PCR technology was applied to determine the transcription numbers of the selected test genes in P orphyra yezoensis, which has been regarded as a potential model species in stress responding. According to the results of photosynthesis parameters, we observed that Y(II) and F v/ F m were significantly affected when stress was imposed on the thalli of P orphyra yezoensis, but underwent almost completely recovered under normal conditions, which were collected for the following experiments. Then three samples, which were treated with different grade stresses combined with salinity, irradiation and temperature, were collected. The transcription numbers of seven constitutive expression genes in above samples were determined after RNA extraction and cDNA synthesis. Finally, a general insight into the selection of internal control genes during stress response was obtained. We found that there were no obvious effects in terms of salinity stress (at salinity 90) on transcription of most genes used in the study. The 18S ribosomal RNA gene had the highest expression level, varying remarkably among different tested groups. RPS8 expression showed a high irregular variance between samples. GAPDH presented comparatively stable expression and could thus be selected as the internal control. EF-1α showed stable expression during the series of multiple-stress tests. Our research provided available references for the selection of internal control genes for transcripts determination of P. yezoensis.

Function of the auxin-responsive gene TaSAUR75 under salt and drought stress

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Yuan Guo

2018-04-01

Full Text Available Small auxin-upregulated RNAs (SAURs are genes regulated by auxin and environmental factors. In this study, we identified a SAUR gene in wheat, TaSAUR75. Under salt stress, TaSAUR75 is downregulated in wheat roots. Subcellular localization revealed that TaSAUR75 was localized in both the cytoplasm and nucleus. Overexpression of TaSAUR75 increased drought and salt tolerance in Arabidopsis. Transgenic lines showed higher root length and survival rate and higher expression of some stress-responsive genes than control plants under salt and drought stress. Less H2O2 accumulated in transgenic lines than in control plants under drought stress. Our findings reveal a positive regulatory role of the auxin-responsive gene TaSAUR75 in plant responses to drought and salt stress and provide a candidate gene for improvement of abiotic stress tolerance in crop breeding.

Expression analysis of MYC genes from Tamarix hispida in response to different abiotic stresses.

Science.gov (United States)

Ji, Xiaoyu; Wang, Yucheng; Liu, Guifeng

2012-01-01

The MYC genes are a group of transcription factors containing both bHLH and ZIP motifs that play important roles in the regulation of abscisic acid (ABA)-responsive genes. In the present study, to investigate the roles of MYC genes under NaCl, osmotic and ABA stress conditions, nine MYC genes were cloned from Tamarix hispida. Real-time reverse-transcriptase (RT)-PCR showed that all nine MYC genes were expressed in root, stem and leaf tissues, but that the levels of the transcripts of these genes in the various tissues differed notably. The MYC genes were highly induced in the roots in response to ABA, NaCl and osmotic stresses after 3 h; however, in the stem and leaf tissues, MYC genes were highly induced only when exposed to these stresses for 6 h. In addition, most of these MYC genes were highly expressed in roots in comparison with stems and leaves. Furthermore, the MYC genes were more highly induced in roots than in stem and leaf tissues, indicating that these genes may play roles in stress responses mainly in the roots rather than the stems and leaves. The results of this present study suggest that MYCs are involved in salt and osmotic stress tolerances and are controlled by the ABA signal transduction pathway.

Dipeptidyl peptidase IV is involved in the cellulose-responsive induction of cellulose biomass-degrading enzyme genes in Aspergillus aculeatus.

Science.gov (United States)

Tani, Shuji; Yuki, Shota; Kunitake, Emi; Sumitani, Jun-Ichi; Kawaguchi, Takashi

2017-06-01

We screened for factors involved in the cellulose-responsive induction of cellulose biomass-degrading enzyme genes from approximately 12,000 Aspergillus aculeatus T-DNA insertion mutants harboring a transcriptional fusion between the FIII-avicelase gene (cbhI) promoter and the orotidine 5'-monophosphate decarboxylase gene. Analysis of 5-fluoroorodic acid (5-FOA) sensitivity, cellulose utilization, and cbhI expression of the mutants revealed that a mutant harboring T-DNA at the dipeptidyl peptidase IV (dppIV) locus had acquired 5-FOA resistance and was deficient in cellulose utilization and cbhI expression. The deletion of dppIV resulted in a significant reduction in the cellulose-responsive expression of both cbhI as well as genes controlled by XlnR-independent and XlnR-dependent signaling pathways at an early phase in A. aculeatus. In contrast, the dppIV deletion did not affect the xylose-responsive expression of genes under the control of XlnR. These results demonstrate that DppIV participates in cellulose-responsive induction in A. aculeatus.

Effect of paraquat-induced oxidative stress on gene expression and aging of the filamentous ascomycete Podospora anserina

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Matthias Wiemer

2014-06-01

Full Text Available Aging of biological systems is influenced by various factors, conditions and processes. Among others, processes allowing organisms to deal with various types of stress are of key importance. In particular, oxidative stress as the result of the generation of reactive oxygen species (ROS at the mitochondrial respiratory chain and the accumulation of ROS-induced molecular damage has been strongly linked to aging. Here we view the impact of ROS from a different angle: their role in the control of gene expression. We report a genome-wide transcriptome analysis of the fungal aging model Podospora anserina grown on medium containing paraquat (PQ. This treatment leads to an increased cellular generation and release of H2O2, a reduced growth rate, and a decrease in lifespan. The combined challenge by PQ and copper has a synergistic negative effect on growth and lifespan. The data from the transcriptome analysis of the wild type cultivated under PQ-stress and their comparison to those of a longitudinal aging study as well as of a copper-uptake longevity mutant of P. anserina revealed that PQ-stress leads to the up-regulation of transcripts coding for components involved in mitochondrial remodeling. PQ also affects the expression of copper-regulated genes suggesting an increase of cytoplasmic copper levels as it has been demonstrated earlier to occur during aging of P. anserina and during senescence of human fibroblasts. This effect may result from the induction of the mitochondrial permeability transition pore via PQ-induced ROS, leading to programmed cell death as part of an evolutionary conserved mechanism involved in biological aging and lifespan control.

The SULTR gene family in maize (Zea mays L.): Gene cloning and expression analyses under sulfate starvation and abiotic stress.

Science.gov (United States)

Huang, Qin; Wang, Meiping; Xia, Zongliang

2018-01-01

Sulfur is an essential macronutrient required for plant growth, development and stress responses. The family of sulfate transporters (SULTRs) mediates the uptake and translocation of sulfate in higher plants. However, basic knowledge of the SULTR gene family in maize (Zea mays L.) is scarce. In this study, a genome-wide bioinformatic analysis of SULTR genes in maize was conducted, and the developmental expression patterns of the genes and their responses to sulfate starvation and abiotic stress were further investigated. The ZmSULTR family includes eight putative members in the maize genome and is clustered into four groups in the phylogenetic tree. These genes displayed differential expression patterns in various organs of maize. For example, expression of ZmSULTR1;1 and ZmSULTR4;1 was high in roots, and transcript levels of ZmSULTR3;1 and ZmSULTR3;3 were high in shoots. Expression of ZmSULTR1;2, ZmSULTR2;1, ZmSULTR3;3, and ZmSULTR4;1 was high in flowers. Also, these eight genes showed differential responses to sulfate deprivation in roots and shoots of maize seedlings. Transcript levels of ZmSULTR1;1, ZmSULTR1;2, and ZmSULTR3;4 were significantly increased in roots during 12-day-sulfate starvation stress, while ZmSULTR3;3 and ZmSULTR3;5 only showed an early response pattern in shoots. In addition, dynamic transcriptional changes determined via qPCR revealed differential expression profiles of these eight ZmSULTR genes in response to environmental stresses such as salt, drought, and heat stresses. Notably, all the genes, except for ZmSULTR3;3, were induced by drought and heat stresses. However, a few genes were induced by salt stress. Physiological determination showed that two important thiol-containing compounds, cysteine and glutathione, increased significantly under these abiotic stresses. The results suggest that members of the SULTR family might function in adaptations to sulfur deficiency stress and adverse growing environments. This study will lay a

Induction of specific Escherichia coli genes by sublethal treatments with alkylating agents.

OpenAIRE

Volkert, M R; Nguyen, D C

1984-01-01

Fusions of the lac operon to genes induced by treatment with sublethal levels of alkylating agents have been selected from random insertions of the Mu-dl(ApRlac) phage by screening for induction of beta-galactosidase activity in the presence of methyl methanesulfonate. Genetic analysis reveals that these fusions resulted from insertion of Mu-dl(ApRlac) into two regions of the chromosome. One region (aidA) is near his and, based on phenotypic effects, appears to represent insertion into the al...

Reconstructing a Network of Stress-Response Regulators via Dynamic System Modeling of Gene Regulation

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Wei-Sheng Wu

2008-01-01

Full Text Available Unicellular organisms such as yeasts have evolved mechanisms to respond to environmental stresses by rapidly reorganizing the gene expression program. Although many stress-response genes in yeast have been discovered by DNA microarrays, the stress-response transcription factors (TFs that regulate these stress-response genes remain to be investigated. In this study, we use a dynamic system model of gene regulation to describe the mechanism of how TFs may control a gene’s expression. Then, based on the dynamic system model, we develop the Stress Regulator Identification Algorithm (SRIA to identify stress-response TFs for six kinds of stresses. We identified some general stress-response TFs that respond to various stresses and some specific stress-response TFs that respond to one specifi c stress. The biological significance of our findings is validated by the literature. We found that a small number of TFs is probably suffi cient to control a wide variety of expression patterns in yeast under different stresses. Two implications can be inferred from this observation. First, the response mechanisms to different stresses may have a bow-tie structure. Second, there may be regulatory cross-talks among different stress responses. In conclusion, this study proposes a network of stress-response regulators and the details of their actions.

Genetically engineered Rice with transcription factor DREB genes for abiotic stress tolerance(abstract)

International Nuclear Information System (INIS)

Datta, S.K.; Datta, K.

2005-01-01

Water stress (drought and Salinity) is the most severe limitation to rice productivity. Several breeding approaches (MAS, QTL) applied to suitable genotypes are in place at IRRI and elsewhere. Phenotyping of water stress tolerance is in progress with potential predictability. Dr. Shinozaki's group has cloned a number of transcription factor genes, which have been shown to work in Arabidopsis to achieve drought, cold, and salinity tolerant plants. None of these genes have as yet displayed their potential functioning in rice. Genetic engineering aims at cross talk between different stress signaling pathways leading to stress tolerance. Osmotic Adjustment (OA) is an effective component of abiotic stress (drought and salinity) tolerance in many plants including rice. When plant experiences water stress, OA contributes to turgor maintenance of both shoots and roots. Conventional breeding could not achieve the OA in rice excepting a few rice cultivars, which are partially adapted to water-stress conditions. Several stress-related genes have now been cloned and transferred in to enhance the osmolytes and some transgenic lines showed increased tolerance to osmotic stress. A few strategies could be effectively deployed for a better understanding of water-stress tolerance in rice and to develop transgenic rice, which can survive for a critical period of water-stress conditions: 1) Switching on of transcription factor regulating the expression of several genes related to abiotic stress, 2) Use of a suitable stress inducible promoter driving the target gene for an efficient and directed expression in plants, 3) Understanding of phenotyping and GxE in a given environment, 4) Selection of a few adaptive rice cultivars suitable in drought/salinity prone areas, 5) Microarray, proteomics, QTL and MAS may expedite the cloning and characterizing the stress induced genes, and 6) Finally, the efficient transformation system for generating a large number of transgenic rice of different

Studies on the induction of mitotic gene conversion by ultraviolet irradiation

International Nuclear Information System (INIS)

Ito, T.; Kobayashi, K.

1975-01-01

Action spectra for the induction of intragenic mitotic recombination (gene conversion) at the trp 5 locus by UV are presented for three cell stages (T 0 , T 9 and T 16 ) taken from synchronously growing cultures of Saccharomyces cerevisiae. The spectra over the range from 230 to 300 nm were taken mostly in 5-nm steps. The peak in the action spectra was significantly shifted, regardless of the stage, towards the longer wavelengths as compared with that of the absorption spectrum of DNA (258nm) or even that of thymine (265nm). In one extreme case ( 16 ), the peak was shifted 17nm from the absorption peak of DNA. Further, the spectrum changed its shape as the cell stage advanced from the non-dividing (unbudded) (T 0 ) to a dividing phase (T 16 ). Furthermore, the induction cross section decreased by a large factor (about 40), regardless of the wavelength, in going from the non-dividing to a dividing phase. From observations of the high photoreversibility of induced conversions, the major primary damage was thought to be pyrimidine dimers in the DNA

Hydrogen-peroxide-induced oxidative stress responses in Desulfovibrio vulgaris Hildenborough

Energy Technology Data Exchange (ETDEWEB)

Zhou, A.; He, Z.; Redding-Johanson, A.M.; Mukhopadhyay, A.; Hemme, C.L.; Joachimiak, M.P.; Bender, K.S.; Keasling, J.D.; Stahl, D.A.; Fields, M.W.; Hazen, T.C.; Arkin, A.P.; Wall, J.D.; Zhou, J.; Luo, F.; Deng, Y.; He, Q.

2010-07-01

To understand how sulphate-reducing bacteria respond to oxidative stresses, the responses of Desulfovibrio vulgaris Hildenborough to H{sub 2}O{sub 2}-induced stresses were investigated with transcriptomic, proteomic and genetic approaches. H{sub 2}O{sub 2} and induced chemical species (e.g. polysulfide, ROS) and redox potential shift increased the expressions of the genes involved in detoxification, thioredoxin-dependent reduction system, protein and DNA repair, and decreased those involved in sulfate reduction, lactate oxidation and protein synthesis. A gene coexpression network analysis revealed complicated network interactions among differentially expressed genes, and suggested possible importance of several hypothetical genes in H{sub 2}O{sub 2} stress. Also, most of the genes in PerR and Fur regulons were highly induced, and the abundance of a Fur regulon protein increased. Mutant analysis suggested that PerR and Fur are functionally overlapped in response to stresses induced by H{sub 2}O{sub 2} and reaction products, and the upregulation of thioredoxin-dependent reduction genes was independent of PerR or Fur. It appears that induction of those stress response genes could contribute to the increased resistance of deletion mutants to H{sub 2}O{sub 2}-induced stresses. In addition, a conceptual cellular model of D. vulgaris responses to H{sub 2}O{sub 2} stress was constructed to illustrate that this bacterium may employ a complicated molecular mechanism to defend against the H{sub 2}O{sub 2}-induced stresses.

Analysis of SOS-Induced Spontaneous Prophage Induction in Corynebacterium glutamicum at the Single-Cell Level

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Nanda, Arun M.; Heyer, Antonia; Krämer, Christina; Grünberger, Alexander; Kohlheyer, Dietrich

2014-01-01

The genome of the Gram-positive soil bacterium Corynebacterium glutamicum ATCC 13032 contains three integrated prophage elements (CGP1 to -3). Recently, it was shown that the large lysogenic prophage CGP3 (∼187 kbp) is excised spontaneously in a small number of cells. In this study, we provide evidence that a spontaneously induced SOS response is partly responsible for the observed spontaneous CGP3 induction. Whereas previous studies focused mainly on the induction of prophages at the population level, we analyzed the spontaneous CGP3 induction at the single-cell level using promoters of phage genes (Pint2 and Plysin) fused to reporter genes encoding fluorescent proteins. Flow-cytometric analysis revealed a spontaneous CGP3 activity in about 0.01 to 0.08% of the cells grown in standard minimal medium, which displayed a significantly reduced viability. A PrecA-eyfp promoter fusion revealed that a small fraction of C. glutamicum cells (∼0.2%) exhibited a spontaneous induction of the SOS response. Correlation of PrecA to the activity of downstream SOS genes (PdivS and PrecN) confirmed a bona fide induction of this stress response rather than stochastic gene expression. Interestingly, the reporter output of PrecA and CGP3 promoter fusions displayed a positive correlation at the single-cell level (ρ = 0.44 to 0.77). Furthermore, analysis of the PrecA-eyfp/Pint2-e2-crimson strain during growth revealed the highest percentage of spontaneous PrecA and Pint2 activity in the early exponential phase, when fast replication occurs. Based on these studies, we postulate that spontaneously occurring DNA damage induces the SOS response, which in turn triggers the induction of lysogenic prophages. PMID:24163339

ABI3 mediates dehydration stress recovery response in Arabidopsis thaliana by regulating expression of downstream genes.

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Bedi, Sonia; Sengupta, Sourabh; Ray, Anagh; Nag Chaudhuri, Ronita

2016-09-01

ABI3, originally discovered as a seed-specific transcription factor is now implicated to act beyond seed physiology, especially during abiotic stress. In non-seed plants, ABI3 is known to act in desiccation stress signaling. Here we show that ABI3 plays a role in dehydration stress response in Arabidopsis. ABI3 gene was upregulated during dehydration stress and its expression was maintained during subsequent stress recovery phases. Comparative gene expression studies in response to dehydration stress and stress recovery were done with genes which had potential ABI3 binding sites in their upstream regulatory regions. Such studies showed that several genes including known seed-specific factors like CRUCIFERIN1, CRUCIFERIN3 and LEA-group of genes like LEA76, LEA6, DEHYDRIN LEA and LEA-LIKE got upregulated in an ABI3-dependent manner, especially during the stress recovery phase. ABI3 got recruited to regions upstream to the transcription start site of these genes during dehydration stress response through direct or indirect DNA binding. Interestingly, ABI3 also binds to its own promoter region during such stress signaling. Nucleosomes covering potential ABI3 binding sites in the upstream sequences of the above-mentioned genes alter positions, and show increased H3 K9 acetylation during stress-induced transcription. ABI3 thus mediates dehydration stress signaling in Arabidopsis through regulation of a group of genes that play a role primarily during stress recovery phase. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Dose response relationship in anti-stress gene regulatory networks.

Science.gov (United States)

Zhang, Qiang; Andersen, Melvin E

2007-03-02

To maintain a stable intracellular environment, cells utilize complex and specialized defense systems against a variety of external perturbations, such as electrophilic stress, heat shock, and hypoxia, etc. Irrespective of the type of stress, many adaptive mechanisms contributing to cellular homeostasis appear to operate through gene regulatory networks that are organized into negative feedback loops. In general, the degree of deviation of the controlled variables, such as electrophiles, misfolded proteins, and O2, is first detected by specialized sensor molecules, then the signal is transduced to specific transcription factors. Transcription factors can regulate the expression of a suite of anti-stress genes, many of which encode enzymes functioning to counteract the perturbed variables. The objective of this study was to explore, using control theory and computational approaches, the theoretical basis that underlies the steady-state dose response relationship between cellular stressors and intracellular biochemical species (controlled variables, transcription factors, and gene products) in these gene regulatory networks. Our work indicated that the shape of dose response curves (linear, superlinear, or sublinear) depends on changes in the specific values of local response coefficients (gains) distributed in the feedback loop. Multimerization of anti-stress enzymes and transcription factors into homodimers, homotrimers, or even higher-order multimers, play a significant role in maintaining robust homeostasis. Moreover, our simulation noted that dose response curves for the controlled variables can transition sequentially through four distinct phases as stressor level increases: initial superlinear with lesser control, superlinear more highly controlled, linear uncontrolled, and sublinear catastrophic. Each phase relies on specific gain-changing events that come into play as stressor level increases. The low-dose region is intrinsically nonlinear, and depending on

Dose response relationship in anti-stress gene regulatory networks.

Directory of Open Access Journals (Sweden)

Qiang Zhang

2007-03-01

Full Text Available To maintain a stable intracellular environment, cells utilize complex and specialized defense systems against a variety of external perturbations, such as electrophilic stress, heat shock, and hypoxia, etc. Irrespective of the type of stress, many adaptive mechanisms contributing to cellular homeostasis appear to operate through gene regulatory networks that are organized into negative feedback loops. In general, the degree of deviation of the controlled variables, such as electrophiles, misfolded proteins, and O2, is first detected by specialized sensor molecules, then the signal is transduced to specific transcription factors. Transcription factors can regulate the expression of a suite of anti-stress genes, many of which encode enzymes functioning to counteract the perturbed variables. The objective of this study was to explore, using control theory and computational approaches, the theoretical basis that underlies the steady-state dose response relationship between cellular stressors and intracellular biochemical species (controlled variables, transcription factors, and gene products in these gene regulatory networks. Our work indicated that the shape of dose response curves (linear, superlinear, or sublinear depends on changes in the specific values of local response coefficients (gains distributed in the feedback loop. Multimerization of anti-stress enzymes and transcription factors into homodimers, homotrimers, or even higher-order multimers, play a significant role in maintaining robust homeostasis. Moreover, our simulation noted that dose response curves for the controlled variables can transition sequentially through four distinct phases as stressor level increases: initial superlinear with lesser control, superlinear more highly controlled, linear uncontrolled, and sublinear catastrophic. Each phase relies on specific gain-changing events that come into play as stressor level increases. The low-dose region is intrinsically nonlinear

Genomewide Expression and Functional Interactions of Genes under Drought Stress in Maize

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Nepolean Thirunavukkarasu

2017-01-01

Full Text Available A genomewide transcriptome assay of two subtropical genotypes of maize was used to observe the expression of genes at seedling stage of drought stress. The number of genes expressed differentially was greater in HKI1532 (a drought tolerant genotype than in PC3 (a drought sensitive genotype, indicating primary differences at the transcriptional level in stress tolerance. The global coexpression networks of the two genotypes differed significantly with respect to the number of modules and the coexpression pattern within the modules. A total of 174 drought-responsive genes were selected from HKI1532, and their coexpression network revealed key correlations between different adaptive pathways, each cluster of the network representing a specific biological function. Transcription factors related to ABA-dependent stomatal closure, signalling, and phosphoprotein cascades work in concert to compensate for reduced photosynthesis. Under stress, water balance was maintained by coexpression of the genes involved in osmotic adjustments and transporter proteins. Metabolism was maintained by the coexpression of genes involved in cell wall modification and protein and lipid metabolism. The interaction of genes involved in crucial biological functions during stress was identified and the results will be useful in targeting important gene interactions to understand drought tolerance in greater detail.

Isolation of a novel abscisic acid stress ripening ( OsASR ) gene ...

African Journals Online (AJOL)

Isolation of a novel abscisic acid stress ripening ( OsASR ) gene from rice and analysis of the response of this gene to abiotic stresses. ... The cDNA with the whole open reading frame (ORF) was amplified by PCR and cloned. Sequence analysis showed that the cDNA encodes a protein of 284 amino acid residues with ...

Rice sHsp genes: genomic organization and expression profiling under stress and development

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Grover Anil

2009-08-01

Full Text Available Abstract Background Heat shock proteins (Hsps constitute an important component in the heat shock response of all living systems. Among the various plant Hsps (i.e. Hsp100, Hsp90, Hsp70 and Hsp20, Hsp20 or small Hsps (sHsps are expressed in maximal amounts under high temperature stress. The characteristic feature of the sHsps is the presence of α-crystallin domain (ACD at the C-terminus. sHsps cooperate with Hsp100/Hsp70 and co-chaperones in ATP-dependent manner in preventing aggregation of cellular proteins and in their subsequent refolding. Database search was performed to investigate the sHsp gene family across rice genome sequence followed by comprehensive expression analysis of these genes. Results We identified 40 α-crystallin domain containing genes in rice. Phylogenetic analysis showed that 23 out of these 40 genes constitute sHsps. The additional 17 genes containing ACD clustered with Acd proteins of Arabidopsis. Detailed scrutiny of 23 sHsp sequences enabled us to categorize these proteins in a revised scheme of classification constituting of 16 cytoplasmic/nuclear, 2 ER, 3 mitochondrial, 1 plastid and 1 peroxisomal genes. In the new classification proposed herein nucleo-cytoplasmic class of sHsps with 9 subfamilies is more complex in rice than in Arabidopsis. Strikingly, 17 of 23 rice sHsp genes were noted to be intronless. Expression analysis based on microarray and RT-PCR showed that 19 sHsp genes were upregulated by high temperature stress. Besides heat stress, expression of sHsp genes was up or downregulated by other abiotic and biotic stresses. In addition to stress regulation, various sHsp genes were differentially upregulated at different developmental stages of the rice plant. Majority of sHsp genes were expressed in seed. Conclusion We identified twenty three sHsp genes and seventeen Acd genes in rice. Three nucleocytoplasmic sHsp genes were found only in monocots. Analysis of expression profiling of sHsp genes revealed

Expression Analysis of MYC Genes from Tamarix hispida in Response to Different Abiotic Stresses

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Guifeng Liu

2012-01-01

Full Text Available The MYC genes are a group of transcription factors containing both bHLH and ZIP motifs that play important roles in the regulation of abscisic acid (ABA-responsive genes. In the present study, to investigate the roles of MYC genes under NaCl, osmotic and ABA stress conditions, nine MYC genes were cloned from Tamarix hispida. Real-time reverse-transcriptase (RT-PCR showed that all nine MYC genes were expressed in root, stem and leaf tissues, but that the levels of the transcripts of these genes in the various tissues differed notably. The MYC genes were highly induced in the roots in response to ABA, NaCl and osmotic stresses after 3 h; however, in the stem and leaf tissues, MYC genes were highly induced only when exposed to these stresses for 6 h. In addition, most of these MYC genes were highly expressed in roots in comparison with stems and leaves. Furthermore, the MYC genes were more highly induced in roots than in stem and leaf tissues, indicating that these genes may play roles in stress responses mainly in the roots rather than the stems and leaves. The results of this present study suggest that MYCs are involved in salt and osmotic stress tolerances and are controlled by the ABA signal transduction pathway.

Co-silencing of tomato S-adenosylhomocysteine hydrolase genes confers increased immunity against Pseudomonas syringae pv. tomato DC3000 and enhanced tolerance to drought stress

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Li Xiao Hui

2015-09-01

Full Text Available S-adenosylhomocysteine hydrolase (SAHH, catalyzing the reversible hydrolysis of S-adenosylhomocysteine to adenosine and homocysteine, is a key enzyme that maintain the cellular methylation potential in all organisms. We report here the biological functions of tomato SlSAHHs in stress response. The tomato genome contains three SlSAHH genes that encode SlSAHH proteins with high level of sequence identity. qRT-PCR analysis revealed that SlSAHHs responded with distinct expression induction patterns to Pseudomonas syringae pv. tomato (Pst DC3000 and Botrytis cinerea as well as to defense signaling hormones such as salicylic acid, jasmonic acid and a precursor of ethylene. Virus-induced gene silencing-based knockdown of individual SlSAHH gene did not affect the growth performance and the response to Pst DC3000. However, co-silencing of three SlSAHH genes using a conserved sequence led to significant inhibition of vegetable growth. The SlSAHH-co-silenced plants displayed increased resistance to Pst DC3000 but did not alter the resistance to B. cinerea. Co-silencing of SlSAHHs resulted in constitutively activated defense responses including elevated SA level, upregulated expression of defense-related and PAMP-triggered immunity marker genes and increased callose deposition and H2O2 accumulation. Furthermore, the SlSAHH-co-silenced plants also exhibited enhanced drought stress tolerance although they had relatively small roots. These data demonstrate that, in addition to the functions in growth and development, SAHHs also play important roles in regulating biotic and abiotic stress responses in plants.

Induction of cytoprotective pathways is central to the extension of lifespan conferred by multiple longevity pathways.

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David E Shore

Full Text Available Many genetic and physiological treatments that extend lifespan also confer resistance to a variety of stressors, suggesting that cytoprotective mechanisms underpin the regulation of longevity. It has not been established, however, whether the induction of cytoprotective pathways is essential for lifespan extension or merely correlated. Using a panel of GFP-fused stress response genes, we identified the suites of cytoprotective pathways upregulated by 160 gene inactivations known to increase Caenorhabditis elegans longevity, including the mitochondrial UPR (hsp-6, hsp-60, the ER UPR (hsp-4, ROS response (sod-3, gst-4, and xenobiotic detoxification (gst-4. We then screened for other gene inactivations that disrupt the induction of these responses by xenobiotic or genetic triggers, identifying 29 gene inactivations required for cytoprotective gene expression. If cytoprotective responses contribute directly to lifespan extension, inactivation of these genes would be expected to compromise the extension of lifespan conferred by decreased insulin/IGF-1 signaling, caloric restriction, or the inhibition of mitochondrial function. We find that inactivation of 25 of 29 cytoprotection-regulatory genes shortens the extension of longevity normally induced by decreased insulin/IGF-1 signaling, disruption of mitochondrial function, or caloric restriction, without disrupting normal longevity nearly as dramatically. These data demonstrate that induction of cytoprotective pathways is central to longevity extension and identify a large set of new genetic components of the pathways that detect cellular damage and couple that detection to downstream cytoprotective effectors.

Histone deacetylase inhibitor valproic acid promotes the induction of pluripotency in mouse fibroblasts by suppressing reprogramming-induced senescence stress

Energy Technology Data Exchange (ETDEWEB)

Zhai, Yingying; Chen, Xi; Yu, Dehai [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China); Stanford University Medical School, Palo Alto Veterans Institute for Research, Palo Alto, CA 94304 (United States); Li, Tao [Stanford University Medical School, Palo Alto Veterans Institute for Research, Palo Alto, CA 94304 (United States); Cui, Jiuwei; Wang, Guanjun [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China); Hu, Ji-Fan, E-mail: jifan@stanford.edu [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China); Stanford University Medical School, Palo Alto Veterans Institute for Research, Palo Alto, CA 94304 (United States); Li, Wei, E-mail: jdyylw@163.com [Stem Cell and Cancer Center, First Affiliated Hospital, Jilin University, Changchun, Jilin 130061 (China)

2015-09-10

Histone deacetylase inhibitor valproic acid (VPA) has been used to increase the reprogramming efficiency of induced pluripotent stem cell (iPSC) from somatic cells, yet the specific molecular mechanisms underlying this effect is unknown. Here, we demonstrate that reprogramming with lentiviruses carrying the iPSC-inducing factors (Oct4-Sox2-Klf4-cMyc, OSKM) caused senescence in mouse fibroblasts, establishing a stress barrier for cell reprogramming. Administration of VPA protected cells from reprogramming-induced senescent stress. Using an in vitro pre-mature senescence model, we found that VPA treatment increased cell proliferation and inhibited apoptosis through the suppression of the p16/p21 pathway. In addition, VPA also inhibited the G2/M phase blockage derived from the senescence stress. These findings highlight the role of VPA in breaking the cell senescence barrier required for the induction of pluripotency. - Highlights: • Histone deacetylase inhibitor valproic acid enhances iPSC induction. • Valproic acid suppresses reprogramming-induced senescence stress. • Valproic acid downregulates the p16/p21 pathway in reprogramming. • This study demonstrates a new mechanistic role of valproic acid in enhancing reprogramming.

A WRKY gene from Tamarix hispida, ThWRKY4, mediates abiotic stress responses by modulating reactive oxygen species and expression of stress-responsive genes.

Science.gov (United States)

Zheng, Lei; Liu, Guifeng; Meng, Xiangnan; Liu, Yujia; Ji, Xiaoyu; Li, Yanbang; Nie, Xianguang; Wang, Yucheng

2013-07-01

WRKY transcription factors are involved in various biological processes, such as development, metabolism and responses to stress. However, their exact roles in abiotic stress tolerance are largely unknown. Here, we demonstrated a working model for the function of a WRKY gene (ThWRKY4) from Tamarix hispida in the stress response. ThWRKY4 is highly induced by abscisic acid (ABA), salt and drought in the early period of stress (stress for 3, 6, or 9 h), which can be regulated by ABF (ABRE binding factors) and Dof (DNA binding with one finger), and also can be crossregulated by other WRKYs and autoregulated as well. Overexpression of ThWRKY4 conferred tolerance to salt, oxidative and ABA treatment in transgenic plants. ThWRKY4 can improve the tolerance to salt and ABA treatment by improving activities of superoxide dismutase and peroxidase, decreasing levels of O2 (-) and H2O2, reducing electrolyte leakage, keeping the loss of chlorophyll, and protecting cells from death. Microarray analyses showed that overexpression of ThWRKY4 in Arabidopsis leads to 165 and 100 genes significantly up- and downregulated, respectively. Promoter scanning analysis revealed that ThWRKY4 regulates the gene expression via binding to W-box motifs present in their promoter regions. This study shows that ThWRKY4 functions as a transcription factor to positively modulate abiotic stress tolerances, and is involved in modulating reactive oxygen species.

Global gene expression in cotton (Gossypium hirsutum L. leaves to waterlogging stress.

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Yanjun Zhang

Full Text Available Cotton is sensitive to waterlogging stress, which usually results in stunted growth and yield loss. To date, the molecular mechanisms underlying the responses to waterlogging in cotton remain elusive. Cotton was grown in a rain-shelter and subjected to 0 (control-, 10-, 15- and 20-d waterlogging at flowering stage. The fourth-leaves on the main-stem from the top were sampled and immediately frozen in liquid nitrogen for physiological measurement. Global gene transcription in the leaves of 15-d waterlogged plants was analyzed by RNA-Seq. Seven hundred and ninety four genes were up-regulated and 1018 genes were down-regulated in waterlogged cotton leaves compared with non-waterlogged control. The differentially expressed genes were mainly related to photosynthesis, nitrogen metabolism, starch and sucrose metabolism, glycolysis and plant hormone signal transduction. KEGG (Kyoto Encyclopedia of Genes and Genomes analysis indicated that most genes related to flavonoid biosynthesis, oxidative phosphorylation, amino acid metabolism and biosynthesis as well as circadian rhythm pathways were differently expressed. Waterlogging increased the expression of anaerobic fermentation related genes, such as alcohol dehydrogenase (ADH, but decreased the leaf chlorophyll concentration and photosynthesis by down-regulating the expression of photosynthesis related genes. Many genes related to plant hormones and transcription factors were differently expressed under waterlogging stress. Most of the ethylene related genes and ethylene-responsive factor-type transcription factors were up-regulated under water-logging stress, suggesting that ethylene may play key roles in the survival of cotton under waterlogging stress.

A nucleotide metabolite controls stress-responsive gene expression and plant development.

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Hao Chen

Full Text Available Abiotic stress, such as drought and high salinity, activates a network of signaling cascades that lead to the expression of many stress-responsive genes in plants. The Arabidopsis FIERY1 (FRY1 protein is a negative regulator of stress and abscisic acid (ABA signaling and exhibits both an inositol polyphosphatase and a 3',5'-bisphosphate nucleotidase activity in vitro. The FRY1 nucleotidase degrades the sulfation byproduct 3'-phosphoadenosine-5'-phosphate (PAP, yet its in vivo functions and particularly its roles in stress gene regulation remain unclear. Here we developed a LC-MS/MS method to quantitatively measure PAP levels in plants and investigated the roles of this nucleotidase activity in stress response and plant development. It was found that PAP level was tightly controlled in plants and did not accumulate to any significant level either under normal conditions or under NaCl, LiCl, cold, or ABA treatments. In contrast, high levels of PAP were detected in multiple mutant alleles of FRY1 but not in mutants of other FRY1 family members, indicating that FRY1 is the major enzyme that hydrolyzes PAP in vivo. By genetically reducing PAP levels in fry1 mutants either through overexpression of a yeast PAP nucleotidase or by generating a triple mutant of fry1 apk1 apk2 that is defective in the biosynthesis of the PAP precursor 3'-phosphoadenosine-5'-phosphosulfate (PAPS, we demonstrated that the developmental defects and superinduction of stress-responsive genes in fry1 mutants correlate with PAP accumulation in planta. We also found that the hypersensitive stress gene regulation in fry1 requires ABH1 but not ABI1, two other negative regulators in ABA signaling pathways. Unlike in yeast, however, FRY1 overexpression in Arabidopsis could not enhance salt tolerance. Taken together, our results demonstrate that PAP is critical for stress gene regulation and plant development, yet the FRY1 nucleotidase that catabolizes PAP may not be an in vivo salt

A nucleotide metabolite controls stress-responsive gene expression and plant development

KAUST Repository

Chen, Hao

2011-10-19

Abiotic stress, such as drought and high salinity, activates a network of signaling cascades that lead to the expression of many stress-responsive genes in plants. The Arabidopsis FIERY1 (FRY1) protein is a negative regulator of stress and abscisic acid (ABA) signaling and exhibits both an inositol polyphosphatase and a 3?,5?-bisphosphate nucleotidase activity in vitro. The FRY1 nucleotidase degrades the sulfation byproduct 3?-phosphoadenosine-5?-phosphate (PAP), yet its in vivo functions and particularly its roles in stress gene regulation remain unclear. Here we developed a LC-MS/MS method to quantitatively measure PAP levels in plants and investigated the roles of this nucleotidase activity in stress response and plant development. It was found that PAP level was tightly controlled in plants and did not accumulate to any significant level either under normal conditions or under NaCl, LiCl, cold, or ABA treatments. In contrast, high levels of PAP were detected in multiple mutant alleles of FRY1 but not in mutants of other FRY1 family members, indicating that FRY1 is the major enzyme that hydrolyzes PAP in vivo. By genetically reducing PAP levels in fry1 mutants either through overexpression of a yeast PAP nucleotidase or by generating a triple mutant of fry1 apk1 apk2 that is defective in the biosynthesis of the PAP precursor 3?-phosphoadenosine-5?-phosphosulfate (PAPS), we demonstrated that the developmental defects and superinduction of stress-responsive genes in fry1 mutants correlate with PAP accumulation in planta. We also found that the hypersensitive stress gene regulation in fry1 requires ABH1 but not ABI1, two other negative regulators in ABA signaling pathways. Unlike in yeast, however, FRY1 overexpression in Arabidopsis could not enhance salt tolerance. Taken together, our results demonstrate that PAP is critical for stress gene regulation and plant development, yet the FRY1 nucleotidase that catabolizes PAP may not be an in vivo salt toxicity target

v-src induction of the TIS10/PGS2 prostaglandin synthase gene is mediated by an ATF/CRE transcription response element.

Science.gov (United States)

Xie, W; Fletcher, B S; Andersen, R D; Herschman, H R

1994-10-01

We recently reported the cloning of a mitogen-inducible prostaglandin synthase gene, TIS10/PGS2. In addition to growth factors and tumor promoters, the v-src oncogene induces TIS10/PGS2 expression in 3T3 cells. Deletion analysis, using luciferase reporters, identifies a region between -80 and -40 nucleotides 5' of the TIS10/PGS2 transcription start site that mediates pp60v-src induction in 3T3 cells. This region contains the sequence CGTCACGTG, which includes overlapping ATF/CRE (CGTCA) and E-box (CACGTG) sequences. Gel shift-oligonucleotide competition experiments with nuclear extracts from cells stably transfected with a temperature-sensitive v-src gene demonstrate that the CGTCACGTG sequence can bind proteins at both the ATF/CRE and E-box sequences. Dominant-negative CREB and Myc proteins that bind DNA, but do not transactivate, block v-src induction of a luciferase reporter driven by the first 80 nucleotides of the TIS10/PGS2 promoter. Mutational analysis distinguishes which TIS10/PGS2 cis-acting element mediates pp60v-src induction. E-box mutation has no effect on the fold induction in response to pp60v-src. In contrast, ATF/CRE mutation attenuates the pp60v-src response. Antibody supershift and methylation interference experiments demonstrate that CREB and at least one other ATF transcription factor in these extracts bind to the TIS10/PGS2 ATF/CRE element. Expression of a dominant-negative ras gene also blocks TIS10/PGS2 induction by v-src. Our data suggest that Ras mediates pp60v-src activation of an ATF transcription factor, leading to induced TIS10/PGS2 expression via the ATF/CRE element of the TIS10/PGS2 promoter. This is the first description of v-src activation of gene expression via an ATF/CRE element.

Transcriptional responses of Arabidopsis thaliana plants to As (V stress

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Yuan Joshua S

2008-08-01

Full Text Available Abstract Background Arsenic is toxic to plants and a common environmental pollutant. There is a strong chemical similarity between arsenate [As (V] and phosphate (Pi. Whole genome oligonucleotide microarrays were employed to investigate the transcriptional responses of Arabidopsis thaliana plants to As (V stress. Results Antioxidant-related genes (i.e. coding for superoxide dismutases and peroxidases play prominent roles in response to arsenate. The microarray experiment revealed induction of chloroplast Cu/Zn superoxide dismutase (SOD (at2g28190, Cu/Zn SOD (at1g08830, as well as an SOD copper chaperone (at1g12520. On the other hand, Fe SODs were strongly repressed in response to As (V stress. Non-parametric rank product statistics were used to detect differentially expressed genes. Arsenate stress resulted in the repression of numerous genes known to be induced by phosphate starvation. These observations were confirmed with qRT-PCR and SOD activity assays. Conclusion Microarray data suggest that As (V induces genes involved in response to oxidative stress and represses transcription of genes induced by phosphate starvation. This study implicates As (V as a phosphate mimic in the cell by repressing genes normally induced when available phosphate is scarce. Most importantly, these data reveal that arsenate stress affects the expression of several genes with little or unknown biological functions, thereby providing new putative gene targets for future research.

Evaluation of Chronic Physical and Psychological Stress Induction on Cardiac Ischemia / Reperfusion Injuries in Isolated Male Rat Heart: The Role of Sympathetic Nervous System

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Kamran Rakhshan

2015-10-01

Full Text Available Exposure to stress leads to physiological changes called “stress response” which are the result ofthe changes in the adrenomedullary hormone system, hypothalamus-pituitary-adrenal (HPA and sympatheticnervous system (SNS activity. In the present study, the effects of chronic physical and psychological stressand also the role of sympathetic system effects in stress on ischemia/reperfusion (I/R injuries have beenstudied in isolated rat heart. Rat heart was isolated and subjected to 30 min regional ischemia and 120 minreperfusion. The daily stress was induced for one week prior to I/R induction. Sympathectomy was donechemically by injection of hydroxyl-dopamine prior to stress induction. There were no significant changes inheart rate and Coronary Flow between groups. Left ventricular developed pressure (LVDP and rate productpressure (RPP in both physical and psychological stress groups decreased significantly compared to those incontrol group (Pgroups. Infarct size significantly increased in both physical and psychological stress groups and control group(Pas compared with stress groups (Ppsychological stress prior to ischemia/reperfusion causes enhancement of myocardial injuries and it seemsthat increased sympathetic activity in response to stress is responsible for these adverse effects of stress onischemic/reperfused heart.

Arousal Predisposition as a Vulnerability Indicator for Psychosis: A General Population Online Stress Induction Study

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Annika Clamor

2015-01-01

Full Text Available Explanatory models ascribe to arousability a central role for the development of psychotic symptoms. Thus, a disposition to hyperarousal (i.e., increased arousal predisposition (AP may serve as an underlying vulnerability indicator for psychosis by interacting with stressors to cause symptoms. In this case, AP, stress-response, and psychotic symptoms should be linked before the development of a diagnosable psychotic disorder. We conducted a cross-sectional online study in a population sample (N=104; Mage=27.7 years, SD=11.2, range 18–70. Participants rated their AP and subclinical psychotic symptoms. Participants reported their stress-levels before and after two stress inductions including an arithmetic and a social stressor. The participants with an increased AP generally felt more stressed. However, AP was not associated with the specific stress-response. As expected, positive psychotic symptoms were significantly associated with AP, but this was not mediated by general stress-levels. Its association to subtle, nonclinical psychotic symptoms supports our assumption that AP could be a vulnerability indicator for psychosis. The trait is easily accessible via a short self-report and could facilitate the identification of people at risk and be a promising target for early stress-management. Further research is needed to clarify its predictive value for stress-responses.

Characterizing gene responses to drought stress in fourwing saltbush [Atriplex canescens (Pursh.) Nutt.)

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Linda S. Adair; David L. Andrews; John Cairney; Edward A. Funkhouser; Ronald J. Newton; Earl F. Aldon

1992-01-01

New techniques in molecular biology can be used to characterize genes whose expression is induced by drought stress. These techniques can be used to understand responses of range plants to environmental stresses at the biochemical and molecular level. For example, they can be used to characterize genes that respond to drought stress conditions in the native shrub

Technique to reduce the shaft torque stress at an induction machine

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Adrian Tulbure

2005-10-01

Full Text Available For the active attenuation at load stress in the drive shaft, the control system should receive as input signal the instantaneous shaft torque value. In this context an intelligent observer for shaft tongue of mains operatea induction machine, which is able to responding by variation of LIF (Load Input Function[1] must be developed. Extensive computer simulation prove the effectiveness of the proposed solution. In order to obtain a practical validation, the stimulated regulator has been designed and tested in the Institute of Electrical Engineering in Clausthal/Germany [2]. This paper contains following parts: Developing the mathematical model, Practical realisation, Simulations and measurements, Evaluating the control solutions and Conclusions.

Counteraction of Oxidative Stress by Vitamin E Affects Epigenetic Regulation by Increasing Global Methylation and Gene Expression of MLH1 and DNMT1 Dose Dependently in Caco-2 Cells

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Katja Zappe

2018-01-01

Full Text Available Obesity- or diabetes-induced oxidative stress is discussed as a major risk factor for DNA damage. Vitamin E and many polyphenols exhibit antioxidative activities with consequences on epigenetic regulation of inflammation and DNA repair. The present study investigated the counteraction of oxidative stress by vitamin E in the colorectal cancer cell line Caco-2 under normal (1 g/l and high (4.5 g/l glucose cell culture condition. Malondialdehyde (MDA as a surrogate marker of lipid peroxidation and reactive oxygen species (ROS was analyzed. Gene expression and promoter methylation of the DNA repair gene MutL homolog 1 (MLH1 and the DNA methyltransferase 1 (DNMT1 as well as global methylation by LINE-1 were investigated. Results revealed a dose-dependent counteracting effect of vitamin E on H2O2-induced oxidative stress. Thereby, 10 μM vitamin E proved to be more efficient than did 50 μM in reducing MDA. Further, an induction of MLH1 and DNMT1 gene expression was noticed, accompanied by an increase in global methylation. Whether LINE-1 hypomethylation is a cause or effect of oxidative stress is still unclear. In conclusion, supplementation of exogenous antioxidants like vitamin E in vitro exhibits beneficial effects concerning oxidative stress as well as epigenetic regulation involved in DNA repair.

Alteration of gene expression during the induction of freezing tolerance in Brassica napus suspension cultures

International Nuclear Information System (INIS)

Johnson-Flanagan, A.M.; Singh, J.

1987-01-01

Brassica napus suspension-cultured cells can be hardened to a lethal temperature for 50% of the sample of -20 0 C in eight days at room temperature with abscisic acid. During the induction of freezing tolerance, changes were observed in the electrophoretic pattern of [ 35 S]methionine labeled polypeptides. In hardening cells, a 20 kilodalton polypeptide was induced on day 2 and its level increased during hardening. The induction of freezing tolerance with nonmaximal hardening regimens also resulted in increases in the 20 kilodalton polypeptide. The 20 kilodalton polypeptide was associated with a membrane fraction enriched in endoplasmic reticulum and was resolved as a single spot by two-dimensional electrophoresis. In vitro translation of mRNA indicate alteration of gene expression during abscisic acid induction of freezing tolerance. The new mRNA encodes a 20 kilodalton polypeptide associated with increased freezing tolerance induced by either abscisic acid or high sucrose. A 20 kilodalton polypeptide was also translated by mRNA isolated from cold-hardened B. napus plants

HEATING AND ULTRAVIOLET LIGHT ACTIVATE ANTI-STRESS GENE FUNCTIONS IN HUMANS

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Victor Fadeevitch Semenkov

2015-07-01

Full Text Available All types of cell stress are accompanied by the activation of anti-stress genes that can suppress ROS synthesis. We hypothesized that different environmental factors would affect organisms through the activation of anti-stress genes by autologous serum (AS proteins, followed by the synthesis of molecules that increase cell resistance to oxidative stress. The goal of this work was to study the influence of AS on ROS production by peripheral blood neutrophils isolated from donors in different age groups. Neutrophils were isolated from 59 donors (38-94 years old. AS was heated at 100˚C for 30 sec. or irradiated by ultraviolet light (UV at 200-280 nm and 8 W for 10 min. Neutrophils were exposed to heat shock at 42˚C for 1 min. (short-term heating stress or 43˚C for 10 min., followed by the determination of the chemiluminescence reaction induced by zymosan. AS can increase or decrease ROS production by neutrophils depending on the structure of the proteins in the serum; these structures can be changed by heating or UV treatment and the temperature of their interaction (4˚C or 37˚C. We propose that the effect of environmental factors on AS proteins can cause an adverse increase in oxidative stress levels due to the functional reduction of anti-stress genes. We found a negative correlation between the quantity of intracellular Hsp70 and levels of intracellular ROS production following 10 minutes of heat shock at 43°C. Short-term heating stress (1 minute at 42°C was followed by a prominent reduction in ROS production. This effect may be a result of the impact of the hormone adrenaline on the functions of anti-stress genes. Indeed, the same effect was observed after treatment of the neutrophils with adrenaline at concentrations of 10-4 M and 10-5 M. In contrast, dexamethasone from the other stress hormone group did not evoke the same effect at the same concentrations.

Induction of ER stress in macrophages of tuberculosis granulomas.

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Tracie A Seimon

2010-09-01

Full Text Available The endoplasmic reticulum (ER stress pathway known as the Unfolded Protein Response (UPR is an adaptive survival pathway that protects cells from the buildup of misfolded proteins, but under certain circumstances it can lead to apoptosis. ER stress has been causally associated with macrophage apoptosis in advanced atherosclerosis of mice and humans. Because atherosclerosis shares certain features with tuberculosis (TB with regard to lesional macrophage accumulation, foam cell formation, and apoptosis, we investigated if the ER stress pathway is activated during TB infection.Here we show that ER stress markers such as C/EBP homologous protein (CHOP; also known as GADD153, phosphorylated inositol-requiring enzyme 1 alpha (Ire1α and eukaryotic initiation factor 2 alpha (eIF2α, and activating transcription factor 3 (ATF3 are expressed in macrophage-rich areas of granulomas in lungs of mice infected with virulent Mycobacterium tuberculosis (Mtb. These areas were also positive for numerous apoptotic cells as assayed by TUNEL. Microarray analysis of human caseous TB granulomas isolated by laser capture microdissection reveal that 73% of genes involved in the UPR are upregulated at the mRNA transcript level. The expression of two ER stress markers, ATF3 and CHOP, were also increased in macrophages of human TB granulomas when assayed by immunohistochemistry. CHOP has been causally associated with ER stress-induced macrophage apoptosis. We found that apoptosis was more abundant in granulomas as compared to non-granulomatous tissue isolated from patients with pulmonary TB, and apoptosis correlated with CHOP expression in areas surrounding the centralized areas of caseation.In summary, ER stress is induced in macrophages of TB granulomas in areas where apoptotic cells accumulate in mice and humans. Although macrophage apoptosis is generally thought to be beneficial in initially protecting the host from Mtb infection, death of infected macrophages in

Preexposure to Olive Oil Polyphenols Extract Increases Oxidative Load and Improves Liver Mass Restoration after Hepatectomy in Mice via Stress-Sensitive Genes

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Jelena Marinić

2016-01-01

Full Text Available Polyphenols can act as oxidants in some conditions, inducing redox-sensitive genes. We investigated the effect of preexposure to the olive oil polyphenols extract (PFE on time-dependent changes in the hepatic oxidative state in a model of liver regeneration—a process in which oxidative stress associated with the metabolic overload accounts for the early events that contribute to the onset of liver self-repair. Liver regeneration was induced by one-third hepatectomy in mice. Prior to hepatectomy, mice were intraperitoneally given either PFE (50 mg/kg body weight or saline for seven consecutive days, while respective controls received vehicle alone. Redox state-regulating enzymes and thiol proteins along with the mRNA levels of Nrf2 gene and its targets γ-glutamylcysteine synthetase and heme oxygenase-1 were determined at different time intervals after hepatectomy. The liver mass restoration was calculated to assess hepatic regeneration. The resulting data demonstrate the effectiveness of preexposure to PFE in stimulating liver regeneration in a model of a small tissue loss which may be ascribed to the transient increase in oxidant load during the first hours after hepatectomy and associated induction of stress response gene-profiles under the control of Nrf2.

The response of early neural genes to FGF signaling or inhibition of BMP indicate the absence of a conserved neural induction module

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Rogers Crystal D

2011-12-01

Full Text Available Abstract Background The molecular mechanism that initiates the formation of the vertebrate central nervous system has long been debated. Studies in Xenopus and mouse demonstrate that inhibition of BMP signaling is sufficient to induce neural tissue in explants or ES cells respectively, whereas studies in chick argue that instructive FGF signaling is also required for the expression of neural genes. Although additional signals may be involved in neural induction and patterning, here we focus on the roles of BMP inhibition and FGF8a. Results To address the question of necessity and sufficiency of BMP inhibition and FGF signaling, we compared the temporal expression of the five earliest genes expressed in the neuroectoderm and determined their requirements for induction at the onset of neural plate formation in Xenopus. Our results demonstrate that the onset and peak of expression of the genes vary and that they have different regulatory requirements and are therefore unlikely to share a conserved neural induction regulatory module. Even though all require inhibition of BMP for expression, some also require FGF signaling; expression of the early-onset pan-neural genes sox2 and foxd5α requires FGF signaling while other early genes, sox3, geminin and zicr1 are induced by BMP inhibition alone. Conclusions We demonstrate that BMP inhibition and FGF signaling induce neural genes independently of each other. Together our data indicate that although the spatiotemporal expression patterns of early neural genes are similar, the mechanisms involved in their expression are distinct and there are different signaling requirements for the expression of each gene.

De novo Transcriptome Assembly of Floral Buds of Pineapple and Identification of Differentially Expressed Genes in Response to Ethephon Induction

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Liu, Chuan-He; Fan, Chao

2016-01-01

A remarkable characteristic of pineapple is its ability to undergo floral induction in response to external ethylene stimulation. However, little information is available regarding the molecular mechanism underlying this process. In this study, the differentially expressed genes (DEGs) in plants exposed to 1.80 mL·L−1 (T1) or 2.40 mL·L−1 ethephon (T2) compared with Ct plants (control, cleaning water) were identified using RNA-seq and gene expression profiling. Illumina sequencing generated 65,825,224 high-quality reads that were assembled into 129,594 unigenes with an average sequence length of 1173 bp. Of these unigenes, 24,775 were assigned to specific KEGG pathways, of which metabolic pathways and biosynthesis of secondary metabolites were the most highly represented. Gene Ontology (GO) analysis of the annotated unigenes revealed that the majority were involved in metabolic and cellular processes, cell and cell part, catalytic activity and binding. Gene expression profiling analysis revealed 3788, 3062, and 758 DEGs in the comparisons of T1 with Ct, T2 with Ct, and T2 with T1, respectively. GO analysis indicated that these DEGs were predominantly annotated to metabolic and cellular processes, cell and cell part, catalytic activity, and binding. KEGG pathway analysis revealed the enrichment of several important pathways among the DEGs, including metabolic pathways, biosynthesis of secondary metabolites and plant hormone signal transduction. Thirteen DEGs were identified as candidate genes associated with the process of floral induction by ethephon, including three ERF-like genes, one ETR-like gene, one LTI-like gene, one FT-like gene, one VRN1-like gene, three FRI-like genes, one AP1-like gene, one CAL-like gene, and one AG-like gene. qPCR analysis indicated that the changes in the expression of these 13 candidate genes were consistent with the alterations in the corresponding RPKM values, confirming the accuracy and credibility of the RNA-seq and gene

Biocomputional construction of a gene network under acid stress in Synechocystis sp. PCC 6803.

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Li, Yi; Rao, Nini; Yang, Feng; Zhang, Ying; Yang, Yang; Liu, Han-ming; Guo, Fengbiao; Huang, Jian

2014-01-01

Acid stress is one of the most serious threats that cyanobacteria have to face, and it has an impact at all levels from genome to phenotype. However, very little is known about the detailed response mechanism to acid stress in this species. We present here a general analysis of the gene regulatory network of Synechocystis sp. PCC 6803 in response to acid stress using comparative genome analysis and biocomputational prediction. In this study, we collected 85 genes and used them as an initial template to predict new genes through co-regulation, protein-protein interactions and the phylogenetic profile, and 179 new genes were obtained to form a complete template. In addition, we found that 11 enriched pathways such as glycolysis are closely related to the acid stress response. Finally, we constructed a regulatory network for the intricate relationship of these genes and summarize the key steps in response to acid stress. This is the first time a bioinformatic approach has been taken systematically to gene interactions in cyanobacteria and the elaboration of their cell metabolism and regulatory pathways under acid stress, which is more efficient than a traditional experimental study. The results also provide theoretical support for similar research into environmental stresses in cyanobacteria and possible industrial applications. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Genome-wide analysis of WRKY gene family in the sesame genome and identification of the WRKY genes involved in responses to abiotic stresses.

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Li, Donghua; Liu, Pan; Yu, Jingyin; Wang, Linhai; Dossa, Komivi; Zhang, Yanxin; Zhou, Rong; Wei, Xin; Zhang, Xiurong

2017-09-11

Sesame (Sesamum indicum L.) is one of the world's most important oil crops. However, it is susceptible to abiotic stresses in general, and to waterlogging and drought stresses in particular. The molecular mechanisms of abiotic stress tolerance in sesame have not yet been elucidated. The WRKY domain transcription factors play significant roles in plant growth, development, and responses to stresses. However, little is known about the number, location, structure, molecular phylogenetics, and expression of the WRKY genes in sesame. We performed a comprehensive study of the WRKY gene family in sesame and identified 71 SiWRKYs. In total, 65 of these genes were mapped to 15 linkage groups within the sesame genome. A phylogenetic analysis was performed using a related species (Arabidopsis thaliana) to investigate the evolution of the sesame WRKY genes. Tissue expression profiles of the WRKY genes demonstrated that six SiWRKY genes were highly expressed in all organs, suggesting that these genes may be important for plant growth and organ development in sesame. Analysis of the SiWRKY gene expression patterns revealed that 33 and 26 SiWRKYs respond strongly to waterlogging and drought stresses, respectively. Changes in the expression of 12 SiWRKY genes were observed at different times after the waterlogging and drought treatments had begun, demonstrating that sesame gene expression patterns vary in response to abiotic stresses. In this study, we analyzed the WRKY family of transcription factors encoded by the sesame genome. Insight was gained into the classification, evolution, and function of the SiWRKY genes, revealing their putative roles in a variety of tissues. Responses to abiotic stresses in different sesame cultivars were also investigated. The results of our study provide a better understanding of the structures and functions of sesame WRKY genes and suggest that manipulating these WRKYs could enhance resistance to waterlogging and drought.

Gene expression profiling of flax (Linum usitatissimum L.) under edaphic stress.

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Dmitriev, Alexey A; Kudryavtseva, Anna V; Krasnov, George S; Koroban, Nadezhda V; Speranskaya, Anna S; Krinitsina, Anastasia A; Belenikin, Maxim S; Snezhkina, Anastasiya V; Sadritdinova, Asiya F; Kishlyan, Natalya V; Rozhmina, Tatiana A; Yurkevich, Olga Yu; Muravenko, Olga V; Bolsheva, Nadezhda L; Melnikova, Nataliya V

2016-11-16

Cultivated flax (Linum usitatissimum L.) is widely used for production of textile, food, chemical and pharmaceutical products. However, various stresses decrease flax production. Search for genes, which are involved in stress response, is necessary for breeding of adaptive cultivars. Imbalanced concentration of nutrient elements in soil decrease flax yields and also results in heritable changes in some flax lines. The appearance of Linum Insertion Sequence 1 (LIS-1) is the most studied modification. However, LIS-1 function is still unclear. High-throughput sequencing of transcriptome of flax plants grown under normal (N), phosphate deficient (P), and nutrient excess (NPK) conditions was carried out using Illumina platform. The assembly of transcriptome was performed, and a total of 34924, 33797, and 33698 unique transcripts for N, P, and NPK sequencing libraries were identified, respectively. We have not revealed any LIS-1 derived mRNA in our sequencing data. The analysis of high-throughput sequencing data allowed us to identify genes with potentially differential expression under imbalanced nutrition. For further investigation with qPCR, 15 genes were chosen and their expression levels were evaluated in the extended sampling of 31 flax plants. Significant expression alterations were revealed for genes encoding WRKY and JAZ protein families under P and NPK conditions. Moreover, the alterations of WRKY family genes differed depending on LIS-1 presence in flax plant genome. Besides, we revealed slight and LIS-1 independent mRNA level changes of KRP2 and ING1 genes, which are adjacent to LIS-1, under nutrition stress. Differentially expressed genes were identified in flax plants, which were grown under phosphate deficiency and excess nutrition, on the basis of high-throughput sequencing and qPCR data. We showed that WRKY and JAS gene families participate in flax response to imbalanced nutrient content in soil. Besides, we have not identified any mRNA, which could be

Gene expression profiling of flax (Linum usitatissimum L. under edaphic stress

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Alexey A. Dmitriev

2016-11-01

Full Text Available Abstract Background Cultivated flax (Linum usitatissimum L. is widely used for production of textile, food, chemical and pharmaceutical products. However, various stresses decrease flax production. Search for genes, which are involved in stress response, is necessary for breeding of adaptive cultivars. Imbalanced concentration of nutrient elements in soil decrease flax yields and also results in heritable changes in some flax lines. The appearance of Linum Insertion Sequence 1 (LIS-1 is the most studied modification. However, LIS-1 function is still unclear. Results High-throughput sequencing of transcriptome of flax plants grown under normal (N, phosphate deficient (P, and nutrient excess (NPK conditions was carried out using Illumina platform. The assembly of transcriptome was performed, and a total of 34924, 33797, and 33698 unique transcripts for N, P, and NPK sequencing libraries were identified, respectively. We have not revealed any LIS-1 derived mRNA in our sequencing data. The analysis of high-throughput sequencing data allowed us to identify genes with potentially differential expression under imbalanced nutrition. For further investigation with qPCR, 15 genes were chosen and their expression levels were evaluated in the extended sampling of 31 flax plants. Significant expression alterations were revealed for genes encoding WRKY and JAZ protein families under P and NPK conditions. Moreover, the alterations of WRKY family genes differed depending on LIS-1 presence in flax plant genome. Besides, we revealed slight and LIS-1 independent mRNA level changes of KRP2 and ING1 genes, which are adjacent to LIS-1, under nutrition stress. Conclusions Differentially expressed genes were identified in flax plants, which were grown under phosphate deficiency and excess nutrition, on the basis of high-throughput sequencing and qPCR data. We showed that WRKY and JAS gene families participate in flax response to imbalanced nutrient content in soil

DinB Upregulation Is the Sole Role of the SOS Response in Stress-Induced Mutagenesis in Escherichia coli

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Galhardo, Rodrigo S.; Do, Robert; Yamada, Masami; Friedberg, Errol C.; Hastings, P. J.; Nohmi, Takehiko; Rosenberg, Susan M.

2009-01-01

Stress-induced mutagenesis is a collection of mechanisms observed in bacterial, yeast, and human cells in which adverse conditions provoke mutagenesis, often under the control of stress responses. Control of mutagenesis by stress responses may accelerate evolution specifically when cells are maladapted to their environments, i.e., are stressed. It is therefore important to understand how stress responses increase mutagenesis. In the Escherichia coli Lac assay, stress-induced point mutagenesis requires induction of at least two stress responses: the RpoS-controlled general/starvation stress response and the SOS DNA-damage response, both of which upregulate DinB error-prone DNA polymerase, among other genes required for Lac mutagenesis. We show that upregulation of DinB is the only aspect of the SOS response needed for stress-induced mutagenesis. We constructed two dinB(oc) (operator-constitutive) mutants. Both produce SOS-induced levels of DinB constitutively. We find that both dinB(oc) alleles fully suppress the phenotype of constitutively SOS-“off” lexA(Ind−) mutant cells, restoring normal levels of stress-induced mutagenesis. Thus, dinB is the only SOS gene required at induced levels for stress-induced point mutagenesis. Furthermore, although spontaneous SOS induction has been observed to occur in only a small fraction of cells, upregulation of dinB by the dinB(oc) alleles in all cells does not promote a further increase in mutagenesis, implying that SOS induction of DinB, although necessary, is insufficient to differentiate cells into a hypermutable condition. PMID:19270270

Characterization of three Agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes.

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Metts, J; West, J; Doares, S H; Matthysse, A G

1991-02-01

Three Agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. Two of the mutants were avirulent on all hosts tested. The third mutant, Ivr-211, was a host range mutant which was avirulent on Bryophyllum diagremontiana, Nicotiana tabacum, N. debneyi, N. glauca, and Daucus carota but was virulent on Zinnia elegans and Lycopersicon esculentum (tomato). That the mutant phenotype was due to the transposon insertion was determined by cloning the DNA containing the transposon insertion and using the cloned DNA to replace the wild-type DNA in the parent bacterial strain by marker exchange. The transposon insertions in the three mutants mapped at three widely separated locations on the bacterial chromosome. The effects of the mutations on various steps in tumor formation were examined. All three mutants showed no alteration in binding to carrot cells. However, none of the mutants showed any induction of vir genes by acetosyringone under conditions in which the parent strain showed vir gene induction. When the mutant bacteria were examined for changes in surface components, it was found that all three of the mutants showed a similar alteration in lipopolysaccharide (LPS). LPS from the mutants was larger in size and more heavily saccharide substituted than LPS from the parent strain. Two of the mutants showed no detectable alteration in outer membrane and periplasmic space proteins. The third mutant, Ivr-225, was missing a 79-kDa surface peptide. The reason(s) for the failure of vir gene induction in these mutants and its relationship, if any, to the observed alteration in LPS are unknown.

Effects of stress and adrenalectomy on activity-regulated cytoskeleton protein (Arc) gene expression

DEFF Research Database (Denmark)

Mikkelsen, Jens D; Larsen, Marianne Hald

2006-01-01

Activity-regulated cytoskeletal-associated protein (Arc) is an effector immediate early gene induced by novelty and involved in consolidation of long-term memory. Since activation of glucocorticoid receptors is a prerequisite for memory consolidation, we therefore aimed to study the effect of acute...... restraint stress on Arc gene expression in adrenalectomized rats. Acute stress produced a significant increase in Arc gene expression in the medial prefrontal cortex, but not in the parietal cortex or in the pyramidal cell layer of the hippocampus. The basal level of Arc mRNA in adrenalectomized animals...... was high in the medial prefrontal cortex and unaffected by acute stress in these animals. These data are consistent with the role of Arc as an integrative modulator of synaptic plasticity by emphasizing the potential role of stress and glucocorticoids in the control of Arc gene expression....

Cocaine induces astrocytosis through ER stress-mediated activation of autophagy

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Periyasamy, Palsamy; Guo, Ming-Lei; Buch, Shilpa

2016-01-01

ABSTRACT Cocaine is known to induce inflammation, thereby contributing in part, to the pathogenesis of neurodegeneration. A recent study from our lab has revealed a link between macroautophagy/autophagy and microglial activation. The current study was aimed at investigating whether cocaine could also mediate activation of astrocytes and, whether this process involved induction of autophagy. Our findings demonstrated that cocaine mediated the activation of astrocytes by altering the levels of autophagy markers, such as BECN1, ATG5, MAP1LC3B-II, and SQSTM1 in both human A172 astrocytoma cells and primary human astrocytes. Furthermore, cocaine treatment resulted in increased formation of endogenous MAP1LC3B puncta in human astrocytes. Additionally, astrocytes transfected with the GFP-MAP1LC3B plasmid also demonstrated cocaine-mediated upregulation of the green fluorescent MAP1LC3B puncta. Cocaine-mediated induction of autophagy involved upstream activation of ER stress proteins such as EIF2AK3, ERN1, ATF6 since blockage of autophagy using either pharmacological or gene-silencing approaches, had no effect on cocaine-mediated induction of ER stress. Using both pharmacological and gene-silencing approaches to block either ER stress or autophagy, our findings demonstrated that cocaine-induced activation of astrocytes (measured by increased levels of GFAP) involved sequential activation of ER stress and autophagy. Cocaine-mediated-increased upregulation of GFAP correlated with increased expression of proinflammatory mediators such as TNF, IL1B, and IL6. In conclusion, these findings reveal an association between ER stress-mediated autophagy and astrogliosis in cocaine-treated astrocytes. Intervention of ER stress and/or autophagy signaling would thus be promising therapeutic targets for abrogating cocaine-mediated neuroinflammation. PMID:27337297

Temperature and Oxidative Stress as Triggers for Virulence Gene Expression in Pathogenic Leptospira spp.

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Tricia Fraser

2017-05-01

Full Text Available Leptospirosis is a zooanthroponosis aetiologically caused by pathogenic bacteria belonging to the genus, Leptospira. Environmental signals such as increases in temperatures or oxidative stress can trigger response regulatory modes of virulence genes during infection. This study sought to determine the effect of temperature and oxidative stress on virulence associated genes in highly passaged Leptospira borgpeterseneii Jules and L. interrogans Portlandvere. Bacteria were grown in EMJH at 30°C, 37°C, or at 30°C before being transferred to 37°C. A total of 14 virulence-associated genes (fliY, invA, lenA, ligB, lipL32, lipL36, lipL41, lipL45, loa22, lsa21, mce, ompL1, sph2, and tlyC were assessed using endpoint PCR. Transcriptional analyses of lenA, lipL32, lipL41, loa22, sph2 were assessed by quantitative real-time RT-PCR at the temperature conditions. To assess oxidative stress, bacteria were exposed to H2O2 for 30 and 60 min with or without the temperature stress. All genes except ligB (for Portlandvere and ligB and mce (for Jules were detectable in the strains. Quantitatively, temperature stress resulted in significant changes in gene expression within species or between species. Temperature changes were more influential in gene expression for Jules, particularly at 30°C and upshift conditions; at 37°C, expression levels were higher for Portlandvere. However, compared to Jules, where temperature was influential in two of five genes, temperature was an essential element in four of five genes in Portlandvere exposed to oxidative stress. At both low and high oxidative stress levels, the interplay between genetic predisposition (larger genome size and temperature was biased towards Portlandvere particularly at 30°C and upshift conditions. While it is clear that expression of many virulence genes in highly passaged strains of Leptospira are attenuated or lost, genetic predisposition, changes in growth temperature and/or oxidative intensity and

Monitoring expression profiles of rice (Oryza sativa L.) genes under abiotic stresses using cDNA Microarray Analysis (abstract)

International Nuclear Information System (INIS)

Rabbani, M.A.

2005-01-01

Transcript regulation in response to cold, drought, high salinity and ABA application was investigated in rice (Oryza sativa L., Nipponbare) with microarray analysis including approx. 1700 independent DNA elements derived from three cDNA libraries constructed from 15-day old rice seedlings stressed with drought, cold and high salinity. A total of 141 non-redundant genes were identified, whose expression ratios were more than three-fold compared with the control genes for at least one of stress treatments in microarray analysis. However, after RNA gel blot analysis, a total of 73 genes were identified, among them the transcripts of 36, 62, 57 and 43 genes were found increased after cold, drought, high salinity and ABA application, respectively. Sixteen of these identified genes have been reported previously to be stress inducible in rice, while 57 of which are novel that have not been reported earlier as stress responsive in rice. We observed a strong association in the expression patterns of stress responsive genes and found 15 stress inducible genes that responded to all four treatments. Based on Venn diagram analysis, 56 genes were induced by both drought and high salinity, whereas 22 genes were upregulated by both cold and high salinity stress. Similarly 43 genes were induced by both drought stress and ABA application, while only 17 genes were identified as cold and ABA inducible genes. These results indicated the existence of greater cross talk between drought, ABA and high salinity stress signaling processes than those between cold and ABA, and cold and high salinity stress signaling pathways. The cold, drought, high salinity and ABA inducible genes were classified into four gene groups from their expression profiles. Analysis of data enabled us to identify a number of promoters and possible cis-acting DNA elements of several genes induced by a variety of abiotic stresses by combining expression data with genomic sequence data of rice. Comparative analysis of

A systems approach identifies networks and genes linking sleep and stress: implications for neuropsychiatric disorders.

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Jiang, Peng; Scarpa, Joseph R; Fitzpatrick, Karrie; Losic, Bojan; Gao, Vance D; Hao, Ke; Summa, Keith C; Yang, He S; Zhang, Bin; Allada, Ravi; Vitaterna, Martha H; Turek, Fred W; Kasarskis, Andrew

2015-05-05

Sleep dysfunction and stress susceptibility are comorbid complex traits that often precede and predispose patients to a variety of neuropsychiatric diseases. Here, we demonstrate multilevel organizations of genetic landscape, candidate genes, and molecular networks associated with 328 stress and sleep traits in a chronically stressed population of 338 (C57BL/6J × A/J) F2 mice. We constructed striatal gene co-expression networks, revealing functionally and cell-type-specific gene co-regulations important for stress and sleep. Using a composite ranking system, we identified network modules most relevant for 15 independent phenotypic categories, highlighting a mitochondria/synaptic module that links sleep and stress. The key network regulators of this module are overrepresented with genes implicated in neuropsychiatric diseases. Our work suggests that the interplay among sleep, stress, and neuropathology emerges from genetic influences on gene expression and their collective organization through complex molecular networks, providing a framework for interrogating the mechanisms underlying sleep, stress susceptibility, and related neuropsychiatric disorders. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Halobenzoquinone-Induced Alteration of Gene Expression Associated with Oxidative Stress Signaling Pathways.

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Li, Jinhua; Moe, Birget; Liu, Yanming; Li, Xing-Fang

2018-06-05

Halobenzoquinones (HBQs) are emerging disinfection byproducts (DBPs) that effectively induce reactive oxygen species and oxidative damage in vitro. However, the impacts of HBQs on oxidative-stress-related gene expression have not been investigated. In this study, we examined alterations in the expression of 44 genes related to oxidative-stress-induced signaling pathways in human uroepithelial cells (SV-HUC-1) upon exposure to six HBQs. The results show the structure-dependent effects of HBQs on the studied gene expression. After 2 h of exposure, the expression levels of 9 to 28 genes were altered, while after 8 h of exposure, the expression levels of 29 to 31 genes were altered. Four genes ( HMOX1, NQO1, PTGS2, and TXNRD1) were significantly upregulated by all six HBQs at both exposure time points. Ingenuity pathway analysis revealed that the Nrf2 pathway was significantly responsive to HBQ exposure. Other canonical pathways responsive to HBQ exposure included GSH redox reductions, superoxide radical degradation, and xenobiotic metabolism signaling. This study has demonstrated that HBQs significantly alter the gene expression of oxidative-stress-related signaling pathways and contributes to the understanding of HBQ-DBP-associated toxicity.

Multiple Cytochrome P450 genes: their constitutive overexpression and permethrin induction in insecticide resistant mosquitoes, Culex quinquefasciatus.

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Liu, Nannan; Li, Ting; Reid, William R; Yang, Ting; Zhang, Lee

2011-01-01

Four cytochrome P450 cDNAs, CYP6AA7, CYP9J40, CYP9J34, and CYP9M10, were isolated from mosquitoes, Culex quinquefasciatus. The P450 gene expression and induction by permethrin were compared for three different mosquito populations bearing different resistance phenotypes, ranging from susceptible (S-Lab), through intermediate (HAmCq(G0), the field parental population) to highly resistant (HAmCq(G8), the 8(th) generation of permethrin selected offspring of HAmCq(G0)). A strong correlation was found for P450 gene expression with the levels of resistance and following permethrin selection at the larval stage of mosquitoes, with the highest expression levels identified in HAmCq(G8), suggesting the importance of CYP6AA7, CYP9J40, CYP9J34, and CYP9M10 in the permethrin resistance of larva mosquitoes. Only CYP6AA7 showed a significant overexpression in HAmCq(G8) adult mosquitoes. Other P450 genes had similar expression levels among the mosquito populations tested, suggesting different P450 genes may be involved in the response to insecticide pressure in different developmental stages. The expression of CYP6AA7, CYP9J34, and CYP9M10 was further induced by permethrin in resistant mosquitoes. Taken together, these results indicate that multiple P450 genes are up-regulated in insecticide resistant mosquitoes through both constitutive overexpression and induction mechanisms, thus increasing the overall expression levels of P450 genes.

Different gene-specific mechanisms determine the 'revised-response' memory transcription patterns of a subset of A. thaliana dehydration stress responding genes.

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Liu, Ning; Ding, Yong; Fromm, Michael; Avramova, Zoya

2014-05-01

Plants that have experienced several exposures to dehydration stress show increased resistance to future exposures by producing faster and/or stronger reactions, while many dehydration stress responding genes in Arabidopsis thaliana super-induce their transcription as a 'memory' from the previous encounter. A previously unknown, rather unusual, memory response pattern is displayed by a subset of the dehydration stress response genes. Despite robustly responding to a first stress, these genes return to their initial, pre-stressed, transcript levels during the watered recovery; surprisingly, they do not respond further to subsequent stresses of similar magnitude and duration. This transcriptional behavior defines the 'revised-response' memory genes. Here, we investigate the molecular mechanisms regulating this transcription memory behavior. Potential roles of abscisic acid (ABA), of transcription factors (TFs) from the ABA signaling pathways (ABF2/3/4 and MYC2), and of histone modifications (H3K4me3 and H3K27me3) as factors in the revised-response transcription memory patterns are elucidated. We identify the TF MYC2 as the critical component for the memory behavior of a specific subset of MYC2-dependent genes. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Fibroblast growth factor 21 participates in adaptation to endoplasmic reticulum stress and attenuates obesity-induced hepatic metabolic stress.

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Kim, Seong Hun; Kim, Kook Hwan; Kim, Hyoung-Kyu; Kim, Mi-Jeong; Back, Sung Hoon; Konishi, Morichika; Itoh, Nobuyuki; Lee, Myung-Shik

2015-04-01

Fibroblast growth factor 21 (FGF21) is an endocrine hormone that exhibits anti-diabetic and anti-obesity activity. FGF21 expression is increased in patients with and mouse models of obesity or nonalcoholic fatty liver disease (NAFLD). However, the functional role and molecular mechanism of FGF21 induction in obesity or NAFLD are not clear. As endoplasmic reticulum (ER) stress is triggered in obesity and NAFLD, we investigated whether ER stress affects FGF21 expression or whether FGF21 induction acts as a mechanism of the unfolded protein response (UPR) adaptation to ER stress induced by chemical stressors or obesity. Hepatocytes or mouse embryonic fibroblasts deficient in UPR signalling pathways and liver-specific eIF2α mutant mice were employed to investigate the in vitro and in vivo effects of ER stress on FGF21 expression, respectively. The in vivo importance of FGF21 induction by ER stress and obesity was determined using inducible Fgf21-transgenic mice and Fgf21-null mice with or without leptin deficiency. We found that ER stressors induced FGF21 expression, which was dependent on a PKR-like ER kinase-eukaryotic translation factor 2α-activating transcription factor 4 pathway both in vitro and in vivo. Fgf21-null mice exhibited increased expression of ER stress marker genes and augmented hepatic lipid accumulation after tunicamycin treatment. However, these changes were attenuated in inducible Fgf21-transgenic mice. We also observed that Fgf21-null mice with leptin deficiency displayed increased hepatic ER stress response and liver injury, accompanied by deteriorated metabolic variables. Our results suggest that FGF21 plays an important role in the adaptive response to ER stress- or obesity-induced hepatic metabolic stress.

Tolerance induction to cytoplasmic beta-galactosidase by hepatic AAV gene transfer: implications for antigen presentation and immunotoxicity.

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Ashley T Martino

2009-08-01

Full Text Available Hepatic gene transfer, in particular using adeno-associated viral (AAV vectors, has been shown to induce immune tolerance to several protein antigens. This approach has been exploited in animal models of inherited protein deficiency for systemic delivery of therapeutic proteins. Adequate levels of transgene expression in hepatocytes induce a suppressive T cell response, thereby promoting immune tolerance. This study addresses the question of whether AAV gene transfer can induce tolerance to a cytoplasmic protein.AAV-2 vector-mediated hepatic gene transfer for expression of cytoplasmic beta-galactosidase (beta-gal was performed in immune competent mice, followed by a secondary beta-gal gene transfer with E1/E3-deleted adenoviral Ad-LacZ vector to provoke a severe immunotoxic response. Transgene expression from the AAV-2 vector in approximately 2% of hepatocytes almost completely protected from inflammatory T cell responses against beta-gal, eliminated antibody formation, and significantly reduced adenovirus-induced hepatotoxicity. Consequently, approximately 10% of hepatocytes continued to express beta-gal 45 days after secondary Ad-LacZ gene transfer, a time point when control mice had lost all Ad-LacZ derived expression. Suppression of inflammatory T cell infiltration in the liver and liver damage was linked to specific transgene expression and was not seen for secondary gene transfer with Ad-GFP. A combination of adoptive transfer studies and flow cytometric analyses demonstrated induction of Treg that actively suppressed CD8(+ T cell responses to beta-gal and that was amplified in liver and spleen upon secondary Ad-LacZ gene transfer.These data demonstrate that tolerance induction by hepatic AAV gene transfer does not require systemic delivery of the transgene product and that expression of a cytoplasmic neo-antigen in few hepatocytes can induce Treg and provide long-term suppression of inflammatory responses and immunotoxicity.

Expression of NCED gene in colored cotton genotypes subjected to water stress

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Alexandre M. S. de Souza

Full Text Available ABSTRACT Considering that the NCED gene acts on the biosynthetic cascade of ABA, a hormone involved in the functioning of stomata and consequently in the regulation of transpiration, the aim of this research was to analyze the expression of this gene in colored cotton genotypes subjected to water stress at the beginning of plant growth. Four colored cotton genotypes were used, subjected to two managements, with and without water stress, beginning the treatments when the blade of the first true leaves reached an area that allowed the evaluation of gas exchange. For the studies of the expression of the NCED gene, via RT-qPCR, leaves were collected on three distinct dates: at 4 and 6 days of water stress, and after the plants regained their turgor. The differential expression of NCED was found in all genotypes, with higher levels of expression related to six days of water stress. When the stomatal conductance was around 25%, there was overexpression in the genotype CNPA 2009.13, followed by CNPA 2009.6, BRS SAFIRA and CNPA 2009.11, confirming the data obtained in the semi-quantitative RT-PCR. The NCED gene is involved in the response to water stress in the vegetative phase of colored cotton.

CAR gene cluster and transcript levels of carotenogenic genes in Rhodotorula mucilaginosa.

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Landolfo, Sara; Ianiri, Giuseppe; Camiolo, Salvatore; Porceddu, Andrea; Mulas, Giuliana; Chessa, Rossella; Zara, Giacomo; Mannazzu, Ilaria

2018-01-01

A molecular approach was applied to the study of the carotenoid biosynthetic pathway of Rhodotorula mucilaginosa. At first, functional annotation of the genome of R. mucilaginosa C2.5t1 was carried out and gene ontology categories were assigned to 4033 predicted proteins. Then, a set of genes involved in different steps of carotenogenesis was identified and those coding for phytoene desaturase, phytoene synthase/lycopene cyclase and carotenoid dioxygenase (CAR genes) proved to be clustered within a region of ~10 kb. Quantitative PCR of the genes involved in carotenoid biosynthesis showed that genes coding for 3-hydroxy-3-methylglutharyl-CoA reductase and mevalonate kinase are induced during exponential phase while no clear trend of induction was observed for phytoene synthase/lycopene cyclase and phytoene dehydrogenase encoding genes. Thus, in R. mucilaginosa the induction of genes involved in the early steps of carotenoid biosynthesis is transient and accompanies the onset of carotenoid production, while that of CAR genes does not correlate with the amount of carotenoids produced. The transcript levels of genes coding for carotenoid dioxygenase, superoxide dismutase and catalase A increased during the accumulation of carotenoids, thus suggesting the activation of a mechanism aimed at the protection of cell structures from oxidative stress during carotenoid biosynthesis. The data presented herein, besides being suitable for the elucidation of the mechanisms that underlie carotenoid biosynthesis, will contribute to boosting the biotechnological potential of this yeast by improving the outcome of further research efforts aimed at also exploring other features of interest.

Inducible nucleosome depletion at OREBP-binding-sites by hypertonic stress.

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Edith H Y Tong

Full Text Available BACKGROUND: Osmotic Response Element-Binding Protein (OREBP, also known as TonEBP or NFAT5, is a unique transcription factor. It is hitherto the only known mammalian transcription factor that regulates hypertonic stress-induced gene transcription. In addition, unlike other monomeric members of the NFAT family, OREBP exists as a homodimer and it is the only transcription factor known to bind naked DNA targets by complete encirclement in vitro. Nevertheless, how OREBP interacts with target DNA, also known as ORE/TonE, and how it elicits gene transcription in vivo, remains unknown. METHODOLOGY: Using hypertonic induction of the aldose reductase (AR gene activation as a model, we showed that OREs contained dynamic nucleosomes. Hypertonic stress induced a rapid and reversible loss of nucleosome(s around the OREs. The loss of nucleosome(s was found to be initiated by an OREBP-independent mechanism, but was significantly potentiated in the presence of OREBP. Furthermore, hypertonic induction of AR gene was associated with an OREBP-dependent hyperacetylation of histones that spanned the 5' upstream sequences and at least some exons of the gene. Nevertheless, nucleosome loss was not regulated by the acetylation status of histone. SIGNIFICANCE: Our findings offer novel insights into the mechanism of OREBP-dependent transcriptional regulation and provide a basis for understanding how histone eviction and transcription factor recruitment are coupled.

Identification and expression analysis of cold and freezing stress responsive genes of Brassica oleracea.

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Ahmed, Nasar Uddin; Jung, Hee-Jeong; Park, Jong-In; Cho, Yong-Gu; Hur, Yoonkang; Nou, Ill-Sup

2015-01-10

Cold and freezing stress is a major environmental constraint to the production of Brassica crops. Enhancement of tolerance by exploiting cold and freezing tolerance related genes offers the most efficient approach to address this problem. Cold-induced transcriptional profiling is a promising approach to the identification of potential genes related to cold and freezing stress tolerance. In this study, 99 highly expressed genes were identified from a whole genome microarray dataset of Brassica rapa. Blast search analysis of the Brassica oleracea database revealed the corresponding homologous genes. To validate their expression, pre-selected cold tolerant and susceptible cabbage lines were analyzed. Out of 99 BoCRGs, 43 were differentially expressed in response to varying degrees of cold and freezing stress in the contrasting cabbage lines. Among the differentially expressed genes, 18 were highly up-regulated in the tolerant lines, which is consistent with their microarray expression. Additionally, 12 BoCRGs were expressed differentially after cold stress treatment in two contrasting cabbage lines, and BoCRG54, 56, 59, 62, 70, 72 and 99 were predicted to be involved in cold regulatory pathways. Taken together, the cold-responsive genes identified in this study provide additional direction for elucidating the regulatory network of low temperature stress tolerance and developing cold and freezing stress resistant Brassica crops. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification and validation of reference genes for quantification of target gene expression with quantitative real-time PCR for tall fescue under four abiotic stresses.

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Zhimin Yang

Full Text Available Tall fescue (Festuca arundinacea Schreb. is widely utilized as a major forage and turfgrass species in the temperate regions of the world and is a valuable plant material for studying molecular mechanisms of grass stress tolerance due to its superior drought and heat tolerance among cool-season species. Selection of suitable reference genes for quantification of target gene expression is important for the discovery of molecular mechanisms underlying improved growth traits and stress tolerance. The stability of nine potential reference genes (ACT, TUB, EF1a, GAPDH, SAND, CACS, F-box, PEPKR1 and TIP41 was evaluated using four programs, GeNorm, NormFinder, BestKeeper, and RefFinder. The combinations of SAND and TUB or TIP41 and TUB were most stably expressed in salt-treated roots or leaves. The combinations of GAPDH with TIP41 or TUB were stable in roots and leaves under drought stress. TIP41 and PEPKR1 exhibited stable expression in cold-treated roots, and the combination of F-box, TIP41 and TUB was also stable in cold-treated leaves. CACS and TUB were the two most stable reference genes in heat-stressed roots. TIP41 combined with TUB and ACT was stably expressed in heat-stressed leaves. Finally, quantitative real-time polymerase chain reaction (qRT-PCR assays of the target gene FaWRKY1 using the identified most stable reference genes confirmed the reliability of selected reference genes. The selection of suitable reference genes in tall fescue will allow for more accurate identification of stress-tolerance genes and molecular mechanisms conferring stress tolerance in this stress-tolerant species.

Distinctive Oxidative Stress Responses to Hydrogen Peroxide in Sulfate Reducing Bacteria Desulfovibrio vulgaris Hildenborough

Energy Technology Data Exchange (ETDEWEB)

Zhou, Aifen; He, Zhili; Redding, A.M.; Mukhopadhyay, Aindrila; Hemme, Christopher L.; Joachimiak, Marcin P.; Bender, Kelly S.; Keasling, Jay D.; Stahl, David A.; Fields, Matthew W.; Hazen, Terry C.; Arkin, Adam P.; Wall, Judy D.; Zhou, Jizhong

2009-01-01

Response of Desulfovibrio vulgaris Hildenborough to hydrogen peroxide (H2O2, 1 mM) was investigated with transcriptomic, proteomic and genetic approaches. Microarray data demonstrated that gene expression was extensively affected by H2O2 with the response peaking at 120 min after H2O2 treatment. Genes affected include those involved with energy production, sulfate reduction, ribosomal structure and translation, H2O2 scavenging, posttranslational modification and DNA repair as evidenced by gene coexpression networks generated via a random matrix-theory based approach. Data from this study support the hypothesis that both PerR and Fur play important roles in H2O2-induced oxidative stress response. First, both PerR and Fur regulon genes were significantly up-regulated. Second, predicted PerR regulon genes ahpC and rbr2 were derepressedin Delta PerR and Delta Fur mutants and induction of neither gene was observed in both Delta PerR and Delta Fur when challenged with peroxide, suggesting possible overlap of these regulons. Third, both Delta PerR and Delta Fur appeared to be more tolerant of H2O2 as measured by optical density. Forth, proteomics data suggested de-repression of Fur during the oxidative stress response. In terms of the intracellular enzymatic H2O2 scavenging, gene expression data suggested that Rdl and Rbr2 may play major roles in the detoxification of H2O2. In addition, induction of thioredoxin reductase and thioredoxin appeared to be independent of PerR and Fur. Considering all data together, D. vulgaris employed a distinctive stress resistance mechanism to defend against increased cellular H2O2, and the temporal gene expression changes were consistent with the slowdown of cell growth at the onset of oxidative stress.

Recovery from heat, salt and osmotic stress in Physcomitrella patens requires a functional small heat shock protein PpHsp16.4.

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Ruibal, Cecilia; Castro, Alexandra; Carballo, Valentina; Szabados, László; Vidal, Sabina

2013-11-05

Plant small heat shock proteins (sHsps) accumulate in response to various environmental stresses, including heat, drought, salt and oxidative stress. Numerous studies suggest a role for these proteins in stress tolerance by preventing stress-induced protein aggregation as well as by facilitating protein refolding by other chaperones. However, in vivo evidence for the involvement of sHsps in tolerance to different stress factors is still missing, mainly due to the lack of appropriate mutants in specific sHsp genes. In this study we characterized the function of a sHsp in abiotic stress tolerance in the moss Physcomitrella patens, a model for primitive land plants. Using suppression subtractive hybridization, we isolated an abscisic acid-upregulated gene from P. patens encoding a 16.4 kDa cytosolic class II sHsp. PpHsp16.4 was also induced by salicylic acid, dithiothreitol (DTT) and by exposure to various stimuli, including osmotic and salt stress, but not by oxidative stress-inducing compounds. Expression of the gene was maintained upon stress relief, suggesting a role for this protein in the recovery stage. PpHsp16.4 is encoded by two identical genes arranged in tandem in the genome. Targeted disruption of both genes resulted in the inability of plants to recover from heat, salt and osmotic stress. In vivo localization studies revealed that PpHsp16.4 localized in cytosolic granules in the vicinity of chloroplasts under non stress conditions, suggesting possible distinct roles for this protein under stress and optimal growth. We identified a member of the class II sHsp family that showed hormonal and abiotic stress gene regulation. Induction of the gene by DTT treatment suggests that damaged proteins may act as signals for the stress-induction of PpHsp16.4. The product of this gene was shown to localize in cytosolic granules near the chloroplasts, suggesting a role for the protein in association with these organelles. Our study provides the first direct genetic

Investigating hsp Gene Expression in Liver of Channa striatus under Heat Stress for Understanding the Upper Thermal Acclimation

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Gopal Krishna Purohit

2014-01-01

Full Text Available Changes in hsp gene expression profiles in murrel Channa striatus experimentally exposed to temperature stress (36°C for 4, 15, and 30 days were investigated; fish collected from aquaculture ponds and maintained in laboratory at the pond temperature (25 ± 1°C served as control. Channa collected from a hot spring runoff (36°C was included in the study to examine the hsp profiles beyond 30 days of exposure. Gene expression analyses of a battery of hsps in liver tissues were carried out by quantitative RT-PCR and protein expressions were analyzed by immunoblotting. hsps could be grouped into three clusters based on similarity in response to heat stress: hsp70, hsp78, and hsp60, whose transcript level continued to increase with duration of exposure; hsp90 and hsp110 that increased to a much higher level and then decreased; hsp27 and hsp47 that did not significantly vary as compared to control. The results suggest that Hsp70, Hsp78, and Hsp60 are involved in thermal acclimation and long term survival at high temperature. Fish living in the hot spring runoff appears to continuously express hsps that can be approximated by long term induction of hsps in farmed fish if temperature of their environment is raised to 36°C.

v-src Induction of the TIS10/PGS2 prostaglandin synthase gene is mediated by an ATF/CRE transcription response element

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Xie, W.; Fletcher, B.S.; Andersen, R.D.; Herschman, H.R. [Univ. of California, Los Angeles, CA (United States)

1994-10-01

The authors recently reported the cloning of a mitogen-inducible prostaglandin synthase gene, TIS10/PGS2. In addition to growth factor and tumor promoters, the v-src oncogene induces TIS10/PGS2 expression in 3T3 cells. Deletion analysis, using luciferase reporters, identifies a region between -80 and -40 nucleotides 5{prime} of the TIS10/PGS2 transcription start site that mediates pp60{sup v-src} induction in 3T3 cells. This region contains the sequence CGTCACGTG, which includes overlapping ATF/CRE (CGTCA) and E-box (CACGTG) sequences. Gel shift-oligonucleotide competition experiments with nuclear extracts from cells stably transfected with a temperature-sensitive v-src gene demonstrate that the CGTCACGTG sequence can bind proteins at both the AFT/CRE and E-box sequences. Dominant-negative CREB and Myc proteins that bind DNA, but do not transactivate, block v-src induction of a luciferase reporter driven by the first 80 nucleotides of the TIS10/PGS2 promoter. Mutational analysis distinguishes which TIS10/PGS2 cis-acting element mediates pp60{sup v-src} induction. E-box mutation has no effect on the fold induction in response to pp60{sup v-src}. In contrast, ATF/CRE mutation attenuates the pp{sup v-src} response. Antibody supershift and methylation interference experiments demonstrate that CREB and at least one other ATF transcription factor in these extracts bind to the TIS10/PGS2 ATF/CRE element. Expression of a dominant-negative ras gene also blocks TIS10/PGS2 induction by v-src. The data suggest that Ras mediates pp60{sup v-src} activation of an ATF transcription factor, leading to induced TIS10/PGS2 expression via the ATF/CRE element of the TIS10/PGS2 promoter. This is the first description of v-src activation of gene expression via an ATF/CRE element. 64 refs., 8 figs.

A Small-Molecule Inducible Synthetic Circuit for Control of the SOS Gene Network without DNA Damage.

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Kubiak, Jeffrey M; Culyba, Matthew J; Liu, Monica Yun; Mo, Charlie Y; Goulian, Mark; Kohli, Rahul M

2017-11-17

The bacterial SOS stress-response pathway is a pro-mutagenic DNA repair system that mediates bacterial survival and adaptation to genotoxic stressors, including antibiotics and UV light. The SOS pathway is composed of a network of genes under the control of the transcriptional repressor, LexA. Activation of the pathway involves linked but distinct events: an initial DNA damage event leads to activation of RecA, which promotes autoproteolysis of LexA, abrogating its repressor function and leading to induction of the SOS gene network. These linked events can each independently contribute to DNA repair and mutagenesis, making it difficult to separate the contributions of the different events to observed phenotypes. We therefore devised a novel synthetic circuit to unlink these events and permit induction of the SOS gene network in the absence of DNA damage or RecA activation via orthogonal cleavage of LexA. Strains engineered with the synthetic SOS circuit demonstrate small-molecule inducible expression of SOS genes as well as the associated resistance to UV light. Exploiting our ability to activate SOS genes independently of upstream events, we further demonstrate that the majority of SOS-mediated mutagenesis on the chromosome does not readily occur with orthogonal pathway induction alone, but instead requires DNA damage. More generally, our approach provides an exemplar for using synthetic circuit design to separate an environmental stressor from its associated stress-response pathway.

DNA demethylases target promoter transposable elements to positively regulate stress responsive genes in Arabidopsis.

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Le, Tuan-Ngoc; Schumann, Ulrike; Smith, Neil A; Tiwari, Sameer; Au, Phil Chi Khang; Zhu, Qian-Hao; Taylor, Jennifer M; Kazan, Kemal; Llewellyn, Danny J; Zhang, Ren; Dennis, Elizabeth S; Wang, Ming-Bo

2014-09-17

DNA demethylases regulate DNA methylation levels in eukaryotes. Arabidopsis encodes four DNA demethylases, DEMETER (DME), REPRESSOR OF SILENCING 1 (ROS1), DEMETER-LIKE 2 (DML2), and DML3. While DME is involved in maternal specific gene expression during seed development, the biological function of the remaining DNA demethylases remains unclear. We show that ROS1, DML2, and DML3 play a role in fungal disease resistance in Arabidopsis. A triple DNA demethylase mutant, rdd (ros1 dml2 dml3), shows increased susceptibility to the fungal pathogen Fusarium oxysporum. We identify 348 genes differentially expressed in rdd relative to wild type, and a significant proportion of these genes are downregulated in rdd and have functions in stress response, suggesting that DNA demethylases maintain or positively regulate the expression of stress response genes required for F. oxysporum resistance. The rdd-downregulated stress response genes are enriched for short transposable element sequences in their promoters. Many of these transposable elements and their surrounding sequences show localized DNA methylation changes in rdd, and a general reduction in CHH methylation, suggesting that RNA-directed DNA methylation (RdDM), responsible for CHH methylation, may participate in DNA demethylase-mediated regulation of stress response genes. Many of the rdd-downregulated stress response genes are downregulated in the RdDM mutants nrpd1 and nrpe1, and the RdDM mutants nrpe1 and ago4 show enhanced susceptibility to F. oxysporum infection. Our results suggest that a primary function of DNA demethylases in plants is to regulate the expression of stress response genes by targeting promoter transposable element sequences.

MicroRNA-target gene responses to lead-induced stress in cotton (Gossypium hirsutum L.).

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He, Qiuling; Zhu, Shuijin; Zhang, Baohong

2014-09-01

MicroRNAs (miRNAs) play key roles in plant responses to various metal stresses. To investigate the miRNA-mediated plant response to heavy metals, cotton (Gossypium hirsutum L.), the most important fiber crop in the world, was exposed to different concentrations (0, 25, 50, 100, and 200 µM) of lead (Pb) and then the toxicological effects were investigated. The expression patterns of 16 stress-responsive miRNAs and 10 target genes were monitored in cotton leaves and roots by quantitative real-time PCR (qRT-PCR); of these selected genes, several miRNAs and their target genes are involved in root development. The results show a reciprocal regulation of cotton response to lead stress by miRNAs. The characterization of the miRNAs and the associated target genes in response to lead exposure would help in defining the potential roles of miRNAs in plant adaptation to heavy metal stress and further understanding miRNA regulation in response to abiotic stress.

Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults

International Nuclear Information System (INIS)

Navarro, Anna; Faria, Melissa; Barata, Carlos; Pina, Benjamin

2011-01-01

Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations. - Coordinated expression of stress genes in zebra mussel.

Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults

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Navarro, Anna; Faria, Melissa; Barata, Carlos [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain); Pina, Benjamin, E-mail: bpcbmc@cid.csic.e [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain)

2011-01-15

Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations. - Coordinated expression of stress genes in zebra mussel.

Endoplasmic Reticulum Stress-Related Factors Protect against Diabetic Retinopathy

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Wei-Kun Hu

2012-01-01

Full Text Available The endoplasmic reticulum (ER is a principal mediator of signal transduction in the cell, and disruption of its normal function (a mechanism known as ER stress has been associated with the pathogenesis of several diseases. ER stress has been demonstrated to contribute to onset and progression of diabetic retinopathy (DR by induction of multiple inflammatory signaling pathways. Recent studies have begun to describe the gene expression profile of ER stress-related genes in DR; moreover, genes that play a protective role against DR have been identified. P58IPK was determined to be able to reduce retinal vascular leakage under high glucose conditions, thus protecting retinal cells. It has also been found by our lab that ER-associated protein degradation factors exhibit significantly different expression patterns in rat retinas under sustained high glucose conditions. Future research based upon these collective genomic findings will contribute to our overall understanding of DR pathogenesis as well as identify potential therapeutic targets.

Identification of a cis-regulatory region of a gene in Arabidopsis thaliana whose induction by dehydration is mediated by abscisic acid and requires protein synthesis.

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Iwasaki, T; Yamaguchi-Shinozaki, K; Shinozaki, K

1995-05-20

In Arabidopsis thaliana, the induction of a dehydration-responsive gene, rd22, is mediated by abscisic acid (ABA) but the gene does not include any sequence corresponding to the consensus ABA-responsive element (ABRE), RYACGTGGYR, in its promoter region. The cis-regulatory region of the rd22 promoter was identified by monitoring the expression of beta-glucuronidase (GUS) activity in leaves of transgenic tobacco plants transformed with chimeric gene fusions constructed between 5'-deleted promoters of rd22 and the coding region of the GUS reporter gene. A 67-bp nucleotide fragment corresponding to positions -207 to -141 of the rd22 promoter conferred responsiveness to dehydration and ABA on a non-responsive promoter. The 67-bp fragment contains the sequences of the recognition sites for some transcription factors, such as MYC, MYB, and GT-1. The fact that accumulation of rd22 mRNA requires protein synthesis raises the possibility that the expression of rd22 might be regulated by one of these trans-acting protein factors whose de novo synthesis is induced by dehydration or ABA. Although the structure of the RD22 protein is very similar to that of a non-storage seed protein, USP, of Vicia faba, the expression of the GUS gene driven by the rd22 promoter in non-stressed transgenic Arabidopsis plants was found mainly in flowers and bolted stems rather than in seeds.

Induction of a program gene expression during osteoblast differentiation with strontium ranelate

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Zhu Lingling; Zaidi, Samir; Peng Yuanzhen; Zhou Hang; Moonga, Baljit S.; Blesius, Alexia; Dupin-Roger, Isabelle; Zaidi, Mone; Sun Li

2007-01-01

Strontium ranelate, a new agent for the treatment of osteoporosis, has been shown stimulate bone formation in various experimental models. This study examines the effect of strontium ranelate on gene expression in osteoblasts, as well as the formation of mineralized (von Kossa-positive) colony-forming unit-osteoblasts (CFU-obs). Bone marrow-derived stromal cells cultured for 21 days under differentiating conditions, when exposed to strontium ranelate, displayed a significant time- and concentration-dependent increase in the expression of the master gene, Runx2, as well as bone sialoprotein (BSP), but interestingly without effects on osteocalcin. This was associated with a significant increase in the formation of CFU-obs at day 21 of culture. In U-33 pre-osteoblastic cells, strontium ranelate significantly enhanced the expression of Runx2 and osteocalcin, but not BSP. Late, more mature osteoblastic OB-6 cells showed significant elevations in BSP and osteocalcin, but with only minimal effects on Runx2. In conclusion, strontium ranelate stimulates osteoblast differentiation, but the induction of the program of gene expression appears to be cell type-specific. The increased osteoblastic differentiation is the likely basis underlying the therapeutic bone-forming actions of strontium ranelate

Genome-wide Identification of WRKY Genes in the Desert Poplar Populus euphratica and Adaptive Evolution of the Genes in Response to Salt Stress.

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Ma, Jianchao; Lu, Jing; Xu, Jianmei; Duan, Bingbing; He, Xiaodong; Liu, Jianquan

2015-01-01

WRKY transcription factors play important roles in plant development and responses to various stresses in plants. However, little is known about the evolution of the WRKY genes in the desert poplar species Populus euphratica, which is highly tolerant of salt stress. In this study, we identified 107 PeWRKY genes from the P. euphratica genome and examined their evolutionary relationships with the WRKY genes of the salt-sensitive congener Populus trichocarpa. Ten PeWRKY genes are specific to P. euphratica, and five of these showed altered expression under salt stress. Furthermore, we found that two pairs of orthologs between the two species showed evidence of positive evolution, with dN/dS ratios>1 (nonsynonymous/synonymous substitutions), and both of them altered their expression in response to salinity stress. These findings suggested that both the development of new genes and positive evolution in some orthologs of the WRKY gene family may have played an important role in the acquisition of high salt tolerance by P. euphratica.

The ionizing radiation inducible gene PARX/ARAP2 participates in Rho and ARF signaling

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Wong, J.A.; Chen, Z.; Zhao, Y.; Vallis, K.A.; Marignani, P.A.; Randazzo, P.A.

2003-01-01

Full text: PARX/ARAP2 is a novel protein that we identified in a gene trap screen for ionizing radiation (IR)-regulated genes. It belongs to a recently described family of proteins that link Rho, ADP-ribosilation factor (ARF) and phosphoinositide 3-kinase (PI3-K) signaling. We have cloned the full length human PARX. Domain analysis of the predicted protein revealed a sterile-alpha motif, five pleckstrin homology domains, a RhoGTPase activating domain (RhoGAP) and an ARF activating domain (ARFGAP). PARX is early inducible by IR in a dose-dependent manner in murine ES cells and in several human B-cell lymphoma lines with up to six-fold induction at the mRNA level at 2 hours (10 Gy). Thus, the kinetics of PARX induction follows the pattern of the rapid response typical of many stress-induced immediate-early genes. PARX expression is also induced in response to other cellular stressors including sorbitol and bleomycin. PARX induction is dependent on PI3-K activity and can be suppressed by the PI3-K inhibitor LY294002. Induction of PARX in response to IR has been observed in cell lines that are p53 mutant indicating up-regulation independent of normal p53 function. The role of p53 in PARX induction is currently being studied using cell lines expressing temperature sensitive p53. Biochemical studies reveal that human PARX has in vivo RhoGAP activity for Rac1 and phosphatidylinositol 3,4,5-trisphosphate dependent ARFGAP activity for ARF1, ARF5 and ARF6. Also, temporal changes in PARX cellular localization following IR are currently being investigated using confocal microscopy. PARX is a gene with a potential role in the cellular response to genotoxic stress, and may illuminate the currently unclear role the small GTPases Rho and ARF play in the radiation response

Identification of Arabidopsis candidate genes in response to biotic and abiotic stresses using comparative microarrays.

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Arjun Sham

Full Text Available Plants have evolved with intricate mechanisms to cope with multiple environmental stresses. To adapt with biotic and abiotic stresses, plant responses involve changes at the cellular and molecular levels. The current study was designed to investigate the effects of combinations of different environmental stresses on the transcriptome level of Arabidopsis genome using public microarray databases. We investigated the role of cyclopentenones in mediating plant responses to environmental stress through TGA (TGACG motif-binding factor transcription factor, independently from jasmonic acid. Candidate genes were identified by comparing plants inoculated with Botrytis cinerea or treated with heat, salt or osmotic stress with non-inoculated or non-treated tissues. About 2.5% heat-, 19% salinity- and 41% osmotic stress-induced genes were commonly upregulated by B. cinerea-treatment; and 7.6%, 19% and 48% of genes were commonly downregulated by B. cinerea-treatment, respectively. Our results indicate that plant responses to biotic and abiotic stresses are mediated by several common regulatory genes. Comparisons between transcriptome data from Arabidopsis stressed-plants support our hypothesis that some molecular and biological processes involved in biotic and abiotic stress response are conserved. Thirteen of the common regulated genes to abiotic and biotic stresses were studied in detail to determine their role in plant resistance to B. cinerea. Moreover, a T-DNA insertion mutant of the Responsive to Dehydration gene (rd20, encoding for a member of the caleosin (lipid surface protein family, showed an enhanced sensitivity to B. cinerea infection and drought. Overall, the overlapping of plant responses to abiotic and biotic stresses, coupled with the sensitivity of the rd20 mutant, may provide new interesting programs for increased plant resistance to multiple environmental stresses, and ultimately increases its chances to survive. Future research

EXPRESSION OF CALCIUM-DEPENDENT PROTEIN KINASE (CDPK GENES IN VITIS AMURENSIS UNDER ABIOTIC STRESS CONDITIONS

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Dubrovina A.S.

2012-08-01

Full Text Available Abiotic stresses, such as extreme temperatures, soil salinity, or water deficit, are one of the major limiting factors of crop productivity worldwide. Examination of molecular and genetic mechanisms of abiotic stress tolerance in plants is of great interest to plant biologists. Calcium-dependent protein kinases (CDPKs, which are the most important Ca2+ sensors in plants, are known to play one of the key roles in plant adaptation to abiotic stress. CDPK is a multigene family of enzymes. Analysis of CDPK gene expression under various abiotic stress conditions would help identify those CDPKs that might play important roles in plant adaptation to abiotic stress. We focused on studying CDPK gene expression under osmotic, water deficit, and temperature stress conditions in a wild-growing grapevine Vitis amurensis Rurp., which is native to the Russian Far East and is known to possess high adaptive potential and high level of resistance against adverse environmental conditions. Healthy V. amurensis cuttings (excised young stems with one healthy leaf were used for the treatments. For the non-stress treatment, we placed the cuttings in distilled water for 12 h at room temperature. For the water-deficit stress, detached cuttings were laid on a paper towel for 12 h at room temperature. For osmotic stress treatments, the cuttings were placed in 0.4 М NaCl and 0.4 М mannitol solutions for 12 h at room temperature. To examine temperature stress tolerance, the V. amurensis cuttings were placed in a growth chamber at +10oC and +37oC for 12 h. The total expression of VaCDPK genes was examined by semiquantitative RT-PCR with degenerate primers designed to the CDPK kinase domain. The total level of CDPK gene expression increased under salt and decreased under low temperature stress conditions. We sequenced 300 clones of the amplified part of different CDPK transcripts obtained from the analyzed cDNA probes. Analysis of the cDNA sequences identified 8 different

Cloning and characterization of the ONAC106 gene from Oryza sativa cultivar Kuku Belang

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Basri, Khairunnisa; Sukiran, Noor Liyana; Zainal, Zamri

2016-11-01

Plants possess different mechanisms in stress response, where induction of stress-responsive genes provides tolerance to unfavorable conditions. Stress-responsive genes are characterized for functional and regulatory genes that help in overcoming stress by molecular, biochemical and morphological adaptations. NAC transcription factors are one of the regulatory proteins that involved in stress signaling pathway. A putative NAC transcription factor, ONAC016 was identified from drought transcriptomic data. Our data suggested that ONAC106 was induced by drought, but its function in abiotic stress is still unclear. In silico analysis of ONAC106 showed that this gene encodes 334 amino acids, and its protein consists of NAM (No Apical Meristem) domain. The orthologue of ONAC106 was present in several Poaceae family members, suggesting that ONAC106 is unique to monocot plants only. We found that ONAC106 was induced by salt and cold stresses, indicating that this gene involves in abiotic stress response. In addition, we also found that ONAC106 might function in defense response to pathogen invasion. The ABRE (Abscisic Acid Regulatory Element) cis-element was identified in the promoter region of ONAC106, suggesting that it may involve in the abscisic acid (ABA)-dependent signaling pathway. Based on this preliminary result, we hypothesize that ONAC106 may play a role in abiotic stress response by regulating ABA-responsive genes.

Recommended Reference Genes for Quantitative PCR Analysis in Soybean Have Variable Stabilities during Diverse Biotic Stresses.

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Raman Bansal

Full Text Available For real-time reverse transcription-PCR (qRT-PCR in soybean, reference genes in different tissues, developmental stages, various cultivars, and under stress conditions have been suggested but their usefulness for research on soybean under various biotic stresses occurring in North-Central U.S. is not known. Here, we investigated the expression stabilities of ten previously recommended reference genes (ABCT, CYP, EF1A, FBOX, GPDH, RPL30, TUA4, TUB4, TUA5, and UNK2 in soybean under biotic stress from Bean pod mottle virus (BPMV, powdery mildew (PMD, soybean aphid (SBA, and two-spotted spider mite (TSSM. BPMV, PMD, SBA, and TSSM are amongst the most common pest problems on soybean in North-Central U.S. and other regions. Reference gene stability was determined using three software algorithms (geNorm, NormFinder, BestKeeper and a web-based tool (RefFinder. Reference genes showed variability in their expression as well as stability across various stressors and the best reference genes were stress-dependent. ABCT and FBOX were found to be the most stable in soybean under both BPMV and SBA stress but these genes had only minimal to moderate stability during PMD and TSSM stress. Expression of TUA4 and CYP was found to be most stable during PMD stress; TUB4 and TUA4 were stable under TSSM stress. Under various biotic stresses on soybean analyzed, GPDH expression was found to be consistently unstable. For all biotic stressors on soybean, we obtained pairwise variation (V2/3 values less than 0.15 which suggested that combined use of the two most stable reference genes would be sufficient for normalization. Further, we demonstrated the utility of normalizing the qRT-PCR data for target genes using the most stable reference genes validated in current study. Following of the recommendations from our current study will enable an accurate and reliable normalization of qRT-PCR data in soybean under biotic stress.

Differential contributions to the transcriptome of duplicated genes in response to abiotic stresses in natural and synthetic polyploids.

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Dong, Shaowei; Adams, Keith L

2011-06-01

Polyploidy has occurred throughout plant evolution and can result in considerable changes to gene expression when it takes place and over evolutionary time. Little is known about the effects of abiotic stress conditions on duplicate gene expression patterns in polyploid plants. We examined the expression patterns of 60 duplicated genes in leaves, roots and cotyledons of allotetraploid Gossypium hirsutum in response to five abiotic stress treatments (heat, cold, drought, high salt and water submersion) using single-strand conformation polymorphism assays, and 20 genes in a synthetic allotetraploid. Over 70% of the genes showed stress-induced changes in the relative expression levels of the duplicates under one or more stress treatments with frequent variability among treatments. Twelve pairs showed opposite changes in expression levels in response to different abiotic stress treatments. Stress-induced expression changes occurred in the synthetic allopolyploid, but there was little correspondence in patterns between the natural and synthetic polyploids. Our results indicate that abiotic stress conditions can have considerable effects on duplicate gene expression in a polyploid, with the effects varying by gene, stress and organ type. Differential expression in response to environmental stresses may be a factor in the preservation of some duplicated genes in polyploids. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

Comparative transcriptome analysis of differentially expressed genes in foxtail millet (Setaria italica L.) during dehydration stress.

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Lata, Charu; Sahu, Pranav Pankaj; Prasad, Manoj

2010-03-19

Dehydration stress is one of the most important abiotic stresses that adversely influence crop growth and productivity. With the aim to understand the molecular mechanisms underlying dehydration stress tolerance in foxtail millet (Setaria italica L.), a drought tolerant crop, we examined its transcriptome changes at two time points (early and late) of dehydration stress. Two suppression subtractive hybridization (SSH) forward libraries were constructed from 21-day old seedlings of tolerant cv. Prasad at 0.5 and 6h PEG-induced dehydration stress. A total of 327 unique ESTs were identified from both libraries and were classified into 11 different categories according to their putative functions. The plant response against dehydration stress was complex, representing major transcripts involved in metabolism, stress, signaling, transcription regulation, translation and proteolysis. By Reverse Northern (RN) technique we identified the differential expression pattern of 327 transcripts, 86 (about 26%) of which showed > or = 1.7-fold induction. Further the obtained results were validated by quantitative real-time PCR (qRT-PCR) to have a comparative expression profiling of randomly chosen 9 up-regulated transcripts (> or =2.5 fold induction) between cv. Prasad (tolerant) and cv. Lepakshi (sensitive) upon dehydration stress. These transcripts showed a differential expression pattern in both cultivars at different time points of stress treatment as analyzed by qRT-PCR. The possible relationship of the identified transcripts with dehydration tolerance mechanism is discussed. Copyright 2010 Elsevier Inc. All rights reserved.

Differential gene expressions in testes of L2 strain Taiwan country chicken in response to acute heat stress.

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Wang, Shih-Han; Cheng, Chuen-Yu; Tang, Pin-Chi; Chen, Chih-Feng; Chen, Hsin-Hsin; Lee, Yen-Pai; Huang, San-Yuan

2013-01-15

Acute heat stress affects genes involved in spermatogenesis in mammals. However, there is apparently no elaborate research on the effects of acute heat stress on gene expression in avian testes. The purpose of this study was to investigate global gene expression in testes of the L2 strain of Taiwan country chicken after acute heat stress. Twelve roosters, 45 weeks old, were allocated into four groups, including control roosters kept at 25 °C, roosters subjected to 38 °C acute heat stress for 4 hours without recovery, with 2-hour recovery, and with 6-hour recovery, respectively. Testis samples were collected for RNA isolation and microarray analysis. Based on gene expression profiles, 169 genes were upregulated and 140 genes were downregulated after heat stress using a cutoff value of twofold or greater change. Based on gene ontology analysis, differentially expressed genes were mainly related to response to stress, transport, signal transduction, and metabolism. A functional network analysis displayed that heat shock protein genes and related chaperones were the major upregulated groups in chicken testes after acute heat stress. A quantitative real-time polymerase chain reaction analysis of mRNA expressions of HSP70, HSP90AA1, BAG3, SERPINB2, HSP25, DNAJA4, CYP3A80, CIRBP, and TAGLN confirmed the results of the microarray analysis. Because the HSP genes (HSP25, HSP70, and HSP90AA1) and the antiapoptotic BAG3 gene were dramatically altered in heat-stressed chicken testes, we concluded that these genes were important factors in the avian testes under acute heat stress. Whether these genes could be candidate genes for thermotolerance in roosters requires further investigation. Copyright © 2013 Elsevier Inc. All rights reserved.

Gene networks specific for innate immunity define post-traumatic stress disorder.

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Breen, M S; Maihofer, A X; Glatt, S J; Tylee, D S; Chandler, S D; Tsuang, M T; Risbrough, V B; Baker, D G; O'Connor, D T; Nievergelt, C M; Woelk, C H

2015-12-01

The molecular factors involved in the development of Post-Traumatic Stress Disorder (PTSD) remain poorly understood. Previous transcriptomic studies investigating the mechanisms of PTSD apply targeted approaches to identify individual genes under a cross-sectional framework lack a holistic view of the behaviours and properties of these genes at the system-level. Here we sought to apply an unsupervised gene-network based approach to a prospective experimental design using whole-transcriptome RNA-Seq gene expression from peripheral blood leukocytes of U.S. Marines (N=188), obtained both pre- and post-deployment to conflict zones. We identified discrete groups of co-regulated genes (i.e., co-expression modules) and tested them for association to PTSD. We identified one module at both pre- and post-deployment containing putative causal signatures for PTSD development displaying an over-expression of genes enriched for functions of innate-immune response and interferon signalling (Type-I and Type-II). Importantly, these results were replicated in a second non-overlapping independent dataset of U.S. Marines (N=96), further outlining the role of innate immune and interferon signalling genes within co-expression modules to explain at least part of the causal pathophysiology for PTSD development. A second module, consequential of trauma exposure, contained PTSD resiliency signatures and an over-expression of genes involved in hemostasis and wound responsiveness suggesting that chronic levels of stress impair proper wound healing during/after exposure to the battlefield while highlighting the role of the hemostatic system as a clinical indicator of chronic-based stress. These findings provide novel insights for early preventative measures and advanced PTSD detection, which may lead to interventions that delay or perhaps abrogate the development of PTSD.

Cross-species multiple environmental stress responses: An integrated approach to identify candidate genes for multiple stress tolerance in sorghum (Sorghum bicolor (L. Moench and related model species.

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Adugna Abdi Woldesemayat

Full Text Available Crop response to the changing climate and unpredictable effects of global warming with adverse conditions such as drought stress has brought concerns about food security to the fore; crop yield loss is a major cause of concern in this regard. Identification of genes with multiple responses across environmental stresses is the genetic foundation that leads to crop adaptation to environmental perturbations.In this paper, we introduce an integrated approach to assess candidate genes for multiple stress responses across-species. The approach combines ontology based semantic data integration with expression profiling, comparative genomics, phylogenomics, functional gene enrichment and gene enrichment network analysis to identify genes associated with plant stress phenotypes. Five different ontologies, viz., Gene Ontology (GO, Trait Ontology (TO, Plant Ontology (PO, Growth Ontology (GRO and Environment Ontology (EO were used to semantically integrate drought related information.Target genes linked to Quantitative Trait Loci (QTLs controlling yield and stress tolerance in sorghum (Sorghum bicolor (L. Moench and closely related species were identified. Based on the enriched GO terms of the biological processes, 1116 sorghum genes with potential responses to 5 different stresses, such as drought (18%, salt (32%, cold (20%, heat (8% and oxidative stress (25% were identified to be over-expressed. Out of 169 sorghum drought responsive QTLs associated genes that were identified based on expression datasets, 56% were shown to have multiple stress responses. On the other hand, out of 168 additional genes that have been evaluated for orthologous pairs, 90% were conserved across species for drought tolerance. Over 50% of identified maize and rice genes were responsive to drought and salt stresses and were co-located within multifunctional QTLs. Among the total identified multi-stress responsive genes, 272 targets were shown to be co-localized within QTLs

AOX1-Subfamily Gene Members in Olea europaea cv. "Galega Vulgar"-Gene Characterization and Expression of Transcripts during IBA-Induced in Vitro Adventitious Rooting.

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Velada, Isabel; Grzebelus, Dariusz; Lousa, Diana; M Soares, Cláudio; Santos Macedo, Elisete; Peixe, Augusto; Arnholdt-Schmitt, Birgit; G Cardoso, Hélia

2018-02-17

Propagation of some Olea europaea L. cultivars is strongly limited due to recalcitrant behavior in adventitious root formation by semi-hardwood cuttings. One example is the cultivar "Galega vulgar". The formation of adventitious roots is considered a morphological response to stress. Alternative oxidase (AOX) is the terminal oxidase of the alternative pathway of the plant mitochondrial electron transport chain. This enzyme is well known to be induced in response to several biotic and abiotic stress situations. This work aimed to characterize the alternative oxidase 1 (AOX1)-subfamily in olive and to analyze the expression of transcripts during the indole-3-butyric acid (IBA)-induced in vitro adventitious rooting (AR) process. OeAOX1a (acc. no. MF410318) and OeAOX1d (acc. no. MF410319) were identified, as well as different transcript variants for both genes which resulted from alternative polyadenylation events. A correlation between transcript accumulation of both OeAOX1a and OeAOX1d transcripts and the three distinct phases (induction, initiation, and expression) of the AR process in olive was observed. Olive AOX1 genes seem to be associated with the induction and development of adventitious roots in IBA-treated explants. A better understanding of the molecular mechanisms underlying the stimulus needed for the induction of adventitious roots may help to develop more targeted and effective rooting induction protocols in order to improve the rooting ability of difficult-to-root cultivars.

Expression profiling on soybean leaves reveals integration of ER- and osmotic-stress pathways

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Dewey Ralph E

2007-11-01

Full Text Available Abstract Background Despite the potential of the endoplasmic reticulum (ER stress response to accommodate adaptive pathways, its integration with other environmental-induced responses is poorly understood in plants. We have previously demonstrated that the ER-stress sensor binding protein (BiP from soybean exhibits an unusual response to drought. The members of the soybean BiP gene family are differentially regulated by osmotic stress and soybean BiP confers tolerance to drought. While these results may reflect crosstalk between the osmotic and ER-stress signaling pathways, the lack of mutants, transcriptional response profiles to stresses and genome sequence information of this relevant crop has limited our attempts to identify integrated networks between osmotic and ER stress-induced adaptive responses. As a fundamental step towards this goal, we performed global expression profiling on soybean leaves exposed to polyethylene glycol treatment (osmotic stress or to ER stress inducers. Results The up-regulated stress-specific changes unmasked the major branches of the ER-stress response, which include enhancing protein folding and degradation in the ER, as well as specific osmotically regulated changes linked to cellular responses induced by dehydration. However, a small proportion (5.5% of total up-regulated genes represented a shared response that seemed to integrate the two signaling pathways. These co-regulated genes were considered downstream targets based on similar induction kinetics and a synergistic response to the combination of osmotic- and ER-stress-inducing treatments. Genes in this integrated pathway with the strongest synergistic induction encoded proteins with diverse roles, such as plant-specific development and cell death (DCD domain-containing proteins, an ubiquitin-associated (UBA protein homolog and NAC domain-containing proteins. This integrated pathway diverged further from characterized specific branches of ER-stress as

Identification of water stress genes in Pinus pinaster Ait. by controlled progressive stress and suppression-subtractive hybridization.

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Perdiguero, Pedro; Collada, Carmen; Barbero, María Del Carmen; García Casado, Gloria; Cervera, María Teresa; Soto, Alvaro

2012-01-01

Climate change is a major challenge particularly for forest tree species, which will have to face the severe alterations of environmental conditions with their current genetic pool. Thus, an understanding of their adaptive responses is of the utmost interest. In this work we have selected Pinus pinaster as a model species. This pine is one of the most important conifers (for which molecular tools and knowledge are far more scarce than for angiosperms) in the Mediterranean Basin, which is characterised in all foreseen scenarios as one of the regions most drastically affected by climate change, mainly because of increasing temperature and, particularly, by increasing drought. We have induced a controlled, increasing water stress by adding PEG to a hydroponic culture. We have generated a subtractive library, with the aim of identifying the genes induced by this stress and have searched for the most reliable expressional candidate genes, based on their overexpression during water stress, as revealed by microarray analysis and confirmed by RT-PCR. We have selected a set of 67 candidate genes belonging to different functional groups that will be useful molecular tools for further studies on drought stress responses, adaptation, and population genomics in conifers, as well as in breeding programs. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Induction of senescence and identification of differentially expressed genes in tomato in response to monoterpene.

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Sumit Ghosh

Full Text Available Monoterpenes, which are among the major components of plant essential oils, are known for their ecological roles as well for pharmaceutical properties. Geraniol, an acyclic monoterpene induces cell cycle arrest and apoptosis/senescence in various cancer cells and plants; however, the genes involved in the process and the underlying molecular mechanisms are not well understood. In this study, we demonstrate that treatment of tomato plants with geraniol results in induction of senescence due to a substantial alteration in transcriptome. We have identified several geraniol-responsive protein encoding genes in tomato using suppression subtractive hybridization (SSH approach. These genes comprise of various components of signal transduction, cellular metabolism, reactive oxygen species (ROS, ethylene signalling, apoptosis and DNA damage response. Upregulation of NADPH oxidase and antioxidant genes, and increase in ROS level after geraniol treatment point towards the involvement of ROS in geraniol-mediated senescence. The delayed onset of seedling death and induced expression of geraniol-responsive genes in geraniol-treated ethylene receptor mutant (Nr suggest that geraniol-mediated senescence involves both ethylene dependent and independent pathways. Moreover, expression analysis during tomato ripening revealed that geraniol-responsive genes are also associated with the natural organ senescence process.

Induction of Senescence and Identification of Differentially Expressed Genes in Tomato in Response to Monoterpene

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Kumar, Vinay; Kumar, Anil; Irfan, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

2013-01-01

Monoterpenes, which are among the major components of plant essential oils, are known for their ecological roles as well for pharmaceutical properties. Geraniol, an acyclic monoterpene induces cell cycle arrest and apoptosis/senescence in various cancer cells and plants; however, the genes involved in the process and the underlying molecular mechanisms are not well understood. In this study, we demonstrate that treatment of tomato plants with geraniol results in induction of senescence due to a substantial alteration in transcriptome. We have identified several geraniol-responsive protein encoding genes in tomato using suppression subtractive hybridization (SSH) approach. These genes comprise of various components of signal transduction, cellular metabolism, reactive oxygen species (ROS), ethylene signalling, apoptosis and DNA damage response. Upregulation of NADPH oxidase and antioxidant genes, and increase in ROS level after geraniol treatment point towards the involvement of ROS in geraniol-mediated senescence. The delayed onset of seedling death and induced expression of geraniol-responsive genes in geraniol-treated ethylene receptor mutant (Nr) suggest that geraniol-mediated senescence involves both ethylene dependent and independent pathways. Moreover, expression analysis during tomato ripening revealed that geraniol-responsive genes are also associated with the natural organ senescence process. PMID:24098759

Identification of late O{sub 3}-responsive genes in Arabidopsis thaliana by cDNA microarray analysis

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D' Haese, D. [Univ. of Antwerp, Dept. of Biology, Antwerp (BE) and Univ. of Newcastle, School of Biology and Psychology, Div. of Biology, Newcastle-Upon-Tyne (United Kingdom); Horemans, N.; Coen, W. De; Guisez, Y. [Univ. of Antwerp, Dept. of Biology, Antwerp (Belgium)

2006-09-15

To better understand the response of a plant to 0{sub 3} stress, an integrated microarray analysis was performed on Arabidopsis plants exposed during 2 days to purified air or 150 nl l{sup -1} O{sub 3}, 8 h day-l. Agilent Arabidopsis 2 Oligo Microarrays were used of which the reliability was confirmed by quantitative real-time PCR of nine randomly selected genes. We confirmed the O{sub 3} responsiveness of heat shock proteins (HSPs), glutathione-S-tranferases and genes involved in cell wall stiffening and microbial defence. Whereas, a previous study revealed that during an early stage of the O{sub 3} stress response, gene expression was strongly dependent on jasmonic acid and ethylene, we report that at a later stage (48 h) synthesis of jasrnonic acid and ethylene was downregulated. In addition, we observed the simultaneous induction of salicylic acid synthesis and genes involved in programmed cell death and senescence. Also typically, the later stage of the response to O{sub 3} appeared to be the induction of the complete pathway leading to the biosynthesis of anthocyanin diglucosides and the induction of thioredoxin-based redox control. Surprisingly absent in the list of induced genes were genes involved in ASC-dependent antioxidation, few of which were found to be induced after 12 h of 0{sub 3} exposure in another study. We discuss these and other particular results of the microarray analysis and provide a map depicting significantly affected genes and their pathways highlighting their interrelationships and subcellular localization. (au)

A NAC transcription factor gene of Chickpea (Cicer arietinum), CarNAC3, is involved in drought stress response and various developmental processes.

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Peng, Hui; Cheng, Hui-Ying; Chen, Chen; Yu, Xin-Wang; Yang, Jia-Ni; Gao, Wen-Rui; Shi, Qing-Hua; Zhang, Hua; Li, Jian-Gui; Ma, Hao

2009-11-15

NAC transcription factors have been found to play important roles in plant development and responses to environmental stresses. Based on two cDNA libraries constructed from the PEG-treated and -nontreated seedling leaves of chickpea, a NAC gene, CarNAC3, was isolated and characterized. The results indicated that CarNAC3 contained 285 amino acids and had a conserved NAC domain. It was localized in the nucleus and possessed trans-activation activity in the C-terminus. Phylogenetic analysis showed that CarNAC3 belonged to the NAP (NAC-like, activated by APETALA3/PISTILLATA) subgroup of the NAC protein family. CarNAC3 exhibited organ-specific expression and its induction was strongly dependent on leaf age. CarNAC3 showed differential expression patterns during seed development and germination, and could be significantly induced by drought stress, abscisic acid (ABA), ethephon (Et) and indole-3-acetic acid (IAA), but was inhibited by N-6-benzyl-adenine (6-BA). Our data suggest that CarNAC3 may be a transcriptional activator involved in drought stress response and various developmental processes.

Identification and characterization of potential NBS-encoding resistance genes and induction kinetics of a putative candidate gene associated with downy mildew resistance in Cucumis

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Wan Hongjian

2010-08-01

Full Text Available Abstract Background Due to the variation and mutation of the races of Pseudoperonospora cubensis, downy mildew has in recent years become the most devastating leaf disease of cucumber worldwide. Novel resistance to downy mildew has been identified in the wild Cucumis species, C. hystrix Chakr. After the successful hybridization between C. hystrix and cultivated cucumber (C. sativus L., an introgression line (IL5211S was identified as highly resistant to downy mildew. Nucleotide-binding site and leucine-rich repeat (NBS-LRR genes are the largest class of disease resistance genes cloned from plant with highly conserved domains, which can be used to facilitate the isolation of candidate genes associated with downy mildew resistance in IL5211S. Results Degenerate primers that were designed based on the conserved motifs in the NBS domain of resistance (R proteins were used to isolate NBS-type sequences from IL5211S. A total of 28 sequences were identified and named as cucumber (C. sativus = CS resistance gene analogs as CSRGAs. Polygenetic analyses separated these sequences into four different classes. Quantitative real-time polymerase chain reaction (qRT-PCR analysis showed that these CSRGAs expressed at different levels in leaves, roots, and stems. In addition, introgression from C. hystrix induced expression of the partial CSRGAs in cultivated cucumber, especially CSRGA23, increased four-fold when compared to the backcross parent CC3. Furthermore, the expression of CSRGA23 under P. cubensis infection and abiotic stresses was also analyzed at different time points. Results showed that the P. cubensis treatment and four tested abiotic stimuli, MeJA, SA, ABA, and H2O2, triggered a significant induction of CSRGA23 within 72 h of inoculation. The results indicate that CSRGA23 may play a critical role in protecting cucumber against P. cubensis through a signaling the pathway triggered by these molecules. Conclusions Four classes of NBS-type RGAs were

Stable expression of mtlD gene imparts multiple stress tolerance in finger millet.

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Ramanna Hema

Full Text Available Finger millet is susceptible to abiotic stresses, especially drought and salinity stress, in the field during seed germination and early stages of seedling development. Therefore developing stress tolerant finger millet plants combating drought, salinity and associated oxidative stress in these two growth stages is important. Cellular protection through osmotic adjustment and efficient free radical scavenging ability during abiotic stress are important components of stress tolerance mechanisms in plants. Mannitol, an osmolyte, is known to scavenge hydroxyl radicals generated during various abiotic stresses and thereby minimize stress damage in several plant species. In this study transgenic finger millet plants expressing the mannitol biosynthetic pathway gene from bacteria, mannitol-1-phosphate dehydrogenase (mtlD, were developed through Agrobacterium tumefaciens-mediated genetic transformation. mtlD gene integration in the putative transgenic plants was confirmed by Southern blot. Further, performance of transgenic finger millet under drought, salinity and oxidative stress was studied at plant level in T1 generation and in T1 and T2 generation seedlings. Results from these experiments showed that transgenic finger millet had better growth under drought and salinity stress compared to wild-type. At plant level, transgenic plants showed better osmotic adjustment and chlorophyll retention under drought stress compared to the wild-type. However, the overall increase in stress tolerance of transgenics for the three stresses, especially for oxidative stress, was only marginal compared to other mtlD gene expressing plant species reported in the literature. Moreover, the Agrobacterium-mediated genetic transformation protocol developed for finger millet in this study can be used to introduce diverse traits of agronomic importance in finger millet.

Stable expression of mtlD gene imparts multiple stress tolerance in finger millet.

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Hema, Ramanna; Vemanna, Ramu S; Sreeramulu, Shivakumar; Reddy, Chandrasekhara P; Senthil-Kumar, Muthappa; Udayakumar, Makarla

2014-01-01

Finger millet is susceptible to abiotic stresses, especially drought and salinity stress, in the field during seed germination and early stages of seedling development. Therefore developing stress tolerant finger millet plants combating drought, salinity and associated oxidative stress in these two growth stages is important. Cellular protection through osmotic adjustment and efficient free radical scavenging ability during abiotic stress are important components of stress tolerance mechanisms in plants. Mannitol, an osmolyte, is known to scavenge hydroxyl radicals generated during various abiotic stresses and thereby minimize stress damage in several plant species. In this study transgenic finger millet plants expressing the mannitol biosynthetic pathway gene from bacteria, mannitol-1-phosphate dehydrogenase (mtlD), were developed through Agrobacterium tumefaciens-mediated genetic transformation. mtlD gene integration in the putative transgenic plants was confirmed by Southern blot. Further, performance of transgenic finger millet under drought, salinity and oxidative stress was studied at plant level in T1 generation and in T1 and T2 generation seedlings. Results from these experiments showed that transgenic finger millet had better growth under drought and salinity stress compared to wild-type. At plant level, transgenic plants showed better osmotic adjustment and chlorophyll retention under drought stress compared to the wild-type. However, the overall increase in stress tolerance of transgenics for the three stresses, especially for oxidative stress, was only marginal compared to other mtlD gene expressing plant species reported in the literature. Moreover, the Agrobacterium-mediated genetic transformation protocol developed for finger millet in this study can be used to introduce diverse traits of agronomic importance in finger millet.

Stress Induction and Visual Working Memory Performance: The Effects of Emotional and Non-Emotional Stimuli

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Zahra Khayyer

2017-05-01

Full Text Available Background Some studies have shown working memory impairment following stressful situations. Also, researchers have found that working memory performance depends on many different factors such as emotional load of stimuli and gender. Objectives The present study aimed to determine the effects of stress induction on visual working memory (VWM performance among female and male university students. Methods This quasi-experimental research employed a posttest with only control group design (within-group study. A total of 62 university students (32 males and 30 females were randomly selected and allocated to experimental and control groups (mean age of 23.73. Using cold presser test (CPT, stress was induced and then, an n-back task was implemented to evaluate visual working memory function (such as the number of true items, time reactions, and the number of wrong items through emotional and non-emotional pictures. 100 pictures were selected from the international affective picture system (IASP with different valences. Results Results showed that stress impaired different visual working memory functions (P < 0.002 for true scores, P < 0.001 for reaction time, and P < 0.002 for wrong items. Conclusions In general, stress significantly decreases the VWM performances. On the one hand, females were strongly impressed by stress more than males and on the other hand, the VWM performance was better for emotional stimuli than non-emotional stimuli.

Phorate-induced oxidative stress, DNA damage and transcriptional activation of p53 and caspase genes in male Wistar rats

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Saquib, Quaiser [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Attia, Sabry M. [Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh (Saudi Arabia); Siddiqui, Maqsood A. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Aboul-Soud, Mourad A.M. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Biochemistry Department, Faculty of Agriculture, Cairo University, 12613 Giza (Egypt); Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Giesy, John P. [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Department of Biomedical and Veterinary Biosciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Canada S7N 5B3 (Canada); Zoology Department and Center for Integrative Toxicology, Michigan State University, East Lansing 48824 (United States); Musarrat, Javed, E-mail: musarratj1@yahoo.com [Department of Zoology, College of Science, King Saud University, Riyadh (Saudi Arabia); Department of Microbiology, Faculty of Agricultural Sciences, AMU, Aligarh (India)

2012-02-15

Male Wistar rats exposed to a systemic organophosphorus insecticide, phorate [O,O-diethyl S-[(ethylthio) methyl] phosphorothioate] at varying oral doses of 0.046, 0.092 or 0.184 mg phorate/kg bw for 14 days, exhibited substantial oxidative stress, cellular DNA damage and activation of apoptosis-related p53, caspase 3 and 9 genes. The histopathological changes including the pyknotic nuclei, inflammatory leukocyte infiltrations, renal necrosis, and cardiac myofiber degeneration were observed in the liver, kidney and heart tissues. Biochemical analysis of catalase and glutathione revealed significantly lesser activities of antioxidative enzymes and lipid peroxidation in tissues of phorate exposed rats. Furthermore, generation of intracellular reactive oxygen species and reduced mitochondrial membrane potential in bone marrow cells confirmed phorate-induced oxidative stress. Significant DNA damage was measured through comet assay in terms of the Olive tail moment in bone marrow cells of treated animals as compared to control. Cell cycle analysis also demonstrated the G{sub 2}/M arrest and appearance of a distinctive SubG{sub 1} peak, which signified induction of apoptosis. Up-regulation of tumor suppressor p53 and caspase 3 and 9 genes, determined by quantitative real-time PCR and enzyme-linked immunosorbent assay, elucidated the activation of intrinsic apoptotic pathways in response to cellular stress. Overall, the results suggest that phorate induces genetic alterations and cellular toxicity, which can adversely affect the normal cellular functioning in rats. -- Highlights: ► This is the first report on molecular toxicity of phorate in an in vivo test system. ► Phorate induces biochemical and histological changes in liver, kidney and heart. ► Rats treated with phorate exhibited DNA damage in bone marrow cells. ► Phorate induces apoptosis, oxidative stress and alters mitochondrial fluorescence. ► Phorate induces transcriptional changes and enhanced

Phorate-induced oxidative stress, DNA damage and transcriptional activation of p53 and caspase genes in male Wistar rats

International Nuclear Information System (INIS)

Saquib, Quaiser; Attia, Sabry M.; Siddiqui, Maqsood A.; Aboul-Soud, Mourad A.M.; Al-Khedhairy, Abdulaziz A.; Giesy, John P.; Musarrat, Javed

2012-01-01

Male Wistar rats exposed to a systemic organophosphorus insecticide, phorate [O,O-diethyl S-[(ethylthio) methyl] phosphorothioate] at varying oral doses of 0.046, 0.092 or 0.184 mg phorate/kg bw for 14 days, exhibited substantial oxidative stress, cellular DNA damage and activation of apoptosis-related p53, caspase 3 and 9 genes. The histopathological changes including the pyknotic nuclei, inflammatory leukocyte infiltrations, renal necrosis, and cardiac myofiber degeneration were observed in the liver, kidney and heart tissues. Biochemical analysis of catalase and glutathione revealed significantly lesser activities of antioxidative enzymes and lipid peroxidation in tissues of phorate exposed rats. Furthermore, generation of intracellular reactive oxygen species and reduced mitochondrial membrane potential in bone marrow cells confirmed phorate-induced oxidative stress. Significant DNA damage was measured through comet assay in terms of the Olive tail moment in bone marrow cells of treated animals as compared to control. Cell cycle analysis also demonstrated the G 2 /M arrest and appearance of a distinctive SubG 1 peak, which signified induction of apoptosis. Up-regulation of tumor suppressor p53 and caspase 3 and 9 genes, determined by quantitative real-time PCR and enzyme-linked immunosorbent assay, elucidated the activation of intrinsic apoptotic pathways in response to cellular stress. Overall, the results suggest that phorate induces genetic alterations and cellular toxicity, which can adversely affect the normal cellular functioning in rats. -- Highlights: ► This is the first report on molecular toxicity of phorate in an in vivo test system. ► Phorate induces biochemical and histological changes in liver, kidney and heart. ► Rats treated with phorate exhibited DNA damage in bone marrow cells. ► Phorate induces apoptosis, oxidative stress and alters mitochondrial fluorescence. ► Phorate induces transcriptional changes and enhanced activities of

Identification of wild soybean (Glycine soja) TIFY family genes and their expression profiling analysis under bicarbonate stress.

Science.gov (United States)

Zhu, Dan; Bai, Xi; Luo, Xiao; Chen, Qin; Cai, Hua; Ji, Wei; Zhu, Yanming

2013-02-01

Wild soybean (Glycine soja L. G07256) exhibits a greater adaptability to soil bicarbonate stress than cultivated soybean, and recent discoveries show that TIFY family genes are involved in the response to several abiotic stresses. A genomic and transcriptomic analysis of all TIFY genes in G. soja, compared with G. max, will provide insight into the function of this gene family in plant bicarbonate stress response. This article identified and characterized 34 TIFY genes in G. soja. Sequence analyses indicated that most GsTIFY proteins had two conserved domains: TIFY and Jas. Phylogenetic analyses suggested that these GsTIFY genes could be classified into two groups. A clustering analysis of all GsTIFY transcript expression profiles from bicarbonate stress treated G. soja showed that there were five different transcript patterns in leaves and six different transcript patterns in roots when the GsTIFY family responds to bicarbonate stress. Moreover, the expression level changes of all TIFY genes in cultivated soybean, treated with bicarbonate stress, were also verified. The expression comparison analysis of TIFYs between wild and cultivated soybeans confirmed that, different from the cultivated soybean, GsTIFY (10a, 10b, 10c, 10d, 10e, 10f, 11a, and 11b) were dramatically up-regulated at the early stage of stress, while GsTIFY 1c and 2b were significantly up-regulated at the later period of stress. The frequently stress responsive and diverse expression profiles of the GsTIFY gene family suggests that this family may play important roles in plant environmental stress responses and adaptation.

Residual stress evaluation by X-Ray diffraction and hole-drilling in an API 5L X70 steel pipe bent by hot induction

International Nuclear Information System (INIS)

Ceglias, Rodrigo Braga; Alves, Juciane Maria; Botelho, Ramon Alves; Baeta Junior, Eustaquio de Souza; Santos, Igor Cuzzuol dos; Moraes, Nicki Robbers Darciano Cajueiro de; Oliveira, Rebeca Vieira de; Diniz, Saulo Brinco; Brandao, Luiz Paulo

2016-01-01

The API 5L X70 steel is used in high-pressure gas transmission pipelines. Because of this, knowledge of presence of residual stress and their magnitude is important to assess the material integrity in service. For the pipeline manufacturing, tubes need to be curved which is often made using the hot induction bending process. This process can introduce different residual stress depending of tube position. For this research, in order to evaluate the residual stress, was used an API 5L X70 tube that was previously curved by hot induction process. Samples were taken from the extrados, intrados, neutral line and straight section of the curved tube. Residual stresses were studied by two conventional methods: X-Ray Diffraction (XRD) and Hole-Drilling, which are destructive and non-destructive methods, respectively, in order to assess their qualitative responses. Each of these methods presents particular methodologies in sample preparation and material analysis, but also they differ in factors such time consumption and cost of the analysis. The qualitative responses obtained by the two different methods were comparable and satisfactory and pointed out the existence of a compressive residual stress state in steel pipe. (author)

Residual stress evaluation by X-Ray diffraction and hole-drilling in an API 5L X70 steel pipe bent by hot induction

Energy Technology Data Exchange (ETDEWEB)

Ceglias, Rodrigo Braga; Alves, Juciane Maria; Botelho, Ramon Alves; Baeta Junior, Eustaquio de Souza; Santos, Igor Cuzzuol dos; Moraes, Nicki Robbers Darciano Cajueiro de; Oliveira, Rebeca Vieira de; Diniz, Saulo Brinco; Brandao, Luiz Paulo, E-mail: brandao@ime.eb.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Mecanica e de Materiais

2016-09-15

The API 5L X70 steel is used in high-pressure gas transmission pipelines. Because of this, knowledge of presence of residual stress and their magnitude is important to assess the material integrity in service. For the pipeline manufacturing, tubes need to be curved which is often made using the hot induction bending process. This process can introduce different residual stress depending of tube position. For this research, in order to evaluate the residual stress, was used an API 5L X70 tube that was previously curved by hot induction process. Samples were taken from the extrados, intrados, neutral line and straight section of the curved tube. Residual stresses were studied by two conventional methods: X-Ray Diffraction (XRD) and Hole-Drilling, which are destructive and non-destructive methods, respectively, in order to assess their qualitative responses. Each of these methods presents particular methodologies in sample preparation and material analysis, but also they differ in factors such time consumption and cost of the analysis. The qualitative responses obtained by the two different methods were comparable and satisfactory and pointed out the existence of a compressive residual stress state in steel pipe. (author)

Systematic dissection of roles for chromatin regulators in a yeast stress response.

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Assaf Weiner

Full Text Available Packaging of eukaryotic genomes into chromatin has wide-ranging effects on gene transcription. Curiously, it is commonly observed that deletion of a global chromatin regulator affects expression of only a limited subset of genes bound to or modified by the regulator in question. However, in many single-gene studies it has become clear that chromatin regulators often do not affect steady-state transcription, but instead are required for normal transcriptional reprogramming by environmental cues. We therefore have systematically investigated the effects of 83 histone mutants, and 119 gene deletion mutants, on induction/repression dynamics of 170 transcripts in response to diamide stress in yeast. Importantly, we find that chromatin regulators play far more pronounced roles during gene induction/repression than they do in steady-state expression. Furthermore, by jointly analyzing the substrates (histone mutants and enzymes (chromatin modifier deletions we identify specific interactions between histone modifications and their regulators. Combining these functional results with genome-wide mapping of several histone marks in the same time course, we systematically investigated the correspondence between histone modification occurrence and function. We followed up on one pathway, finding that Set1-dependent H3K4 methylation primarily acts as a gene repressor during multiple stresses, specifically at genes involved in ribosome biosynthesis. Set1-dependent repression of ribosomal genes occurs via distinct pathways for ribosomal protein genes and ribosomal biogenesis genes, which can be separated based on genetic requirements for repression and based on chromatin changes during gene repression. Together, our dynamic studies provide a rich resource for investigating chromatin regulation, and identify a significant role for the "activating" mark H3K4me3 in gene repression.

Identification of conserved drought stress responsive gene-network across tissues and developmental stages in rice.

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Smita, Shuchi; Katiyar, Amit; Pandey, Dev Mani; Chinnusamy, Viswanathan; Archak, Sunil; Bansal, Kailash Chander

2013-01-01

Identification of genes that are coexpressed across various tissues and environmental stresses is biologically interesting, since they may play coordinated role in similar biological processes. Genes with correlated expression patterns can be best identified by using coexpression network analysis of transcriptome data. In the present study, we analyzed the temporal-spatial coordination of gene expression in root, leaf and panicle of rice under drought stress and constructed network using WGCNA and Cytoscape. Total of 2199 differentially expressed genes (DEGs) were identified in at least three or more tissues, wherein 88 genes have coordinated expression profile among all the six tissues under drought stress. These 88 highly coordinated genes were further subjected to module identification in the coexpression network. Based on chief topological properties we identified 18 hub genes such as ABC transporter, ATP-binding protein, dehydrin, protein phosphatase 2C, LTPL153 - Protease inhibitor, phosphatidylethanolaminebinding protein, lactose permease-related, NADP-dependent malic enzyme, etc. Motif enrichment analysis showed the presence of ABRE cis-elements in the promoters of > 62% of the coordinately expressed genes. Our results suggest that drought stress mediated upregulated gene expression was coordinated through an ABA-dependent signaling pathway across tissues, at least for the subset of genes identified in this study, while down regulation appears to be regulated by tissue specific pathways in rice.

Regulatory role of tetR gene in a novel gene cluster of Acidovorax avenae subsp. avenae RS-1 under oxidative stress

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He eLiu

2014-10-01

Full Text Available Acidovorax avenae subsp. avenae is the causal agent of bacterial brown stripe disease in rice. In this study, we characterized a novel horizontal transfer of a gene cluster, including tetR, on the chromosome of A. avenae subsp. avenae RS-1 by genome-wide analysis. TetR acted as a repressor in this gene cluster and the oxidative stress resistance was enhanced in tetR-deletion mutant strain. Electrophoretic mobility shift assay (EMSA demonstrated that TetR regulator bound directly to the promoter of this gene cluster. Consistently, the results of quantitative real-time PCR also showed alterations in expression of associated genes. Moreover, the proteins affected by TetR under oxidative stress were revealed by comparing proteomic profiles of wild-type and mutant strains via 1D SDS-PAGE and LC-MS/MS analyses. Taken together, our results demonstrated that tetR gene in this novel gene cluster contributed to cell survival under oxidative stress, and TetR protein played an important regulatory role in growth kinetics, biofilm-forming capability, SOD and catalase activity, and oxide detoxicating ability.

Regulatory role of tetR gene in a novel gene cluster of Acidovorax avenae subsp. avenae RS-1 under oxidative stress.

Science.gov (United States)

Liu, He; Yang, Chun-Lan; Ge, Meng-Yu; Ibrahim, Muhammad; Li, Bin; Zhao, Wen-Jun; Chen, Gong-You; Zhu, Bo; Xie, Guan-Lin

2014-01-01

Acidovorax avenae subsp. avenae is the causal agent of bacterial brown stripe disease in rice. In this study, we characterized a novel horizontal transfer of a gene cluster, including tetR, on the chromosome of A. avenae subsp. avenae RS-1 by genome-wide analysis. TetR acted as a repressor in this gene cluster and the oxidative stress resistance was enhanced in tetR-deletion mutant strain. Electrophoretic mobility shift assay demonstrated that TetR regulator bound directly to the promoter of this gene cluster. Consistently, the results of quantitative real-time PCR also showed alterations in expression of associated genes. Moreover, the proteins affected by TetR under oxidative stress were revealed by comparing proteomic profiles of wild-type and mutant strains via 1D SDS-PAGE and LC-MS/MS analyses. Taken together, our results demonstrated that tetR gene in this novel gene cluster contributed to cell survival under oxidative stress, and TetR protein played an important regulatory role in growth kinetics, biofilm-forming capability, superoxide dismutase and catalase activity, and oxide detoxicating ability.

Interaction between the RGS6 gene and psychosocial stress on obesity-related traits.

Science.gov (United States)

Kim, Hyun-Jin; Min, Jin-Young; Min, Kyoung-Bok

2017-03-31

Obesity is a major risk factor for chronic diseases and arises from the interactions between environmental factors and multiple genes. Psychosocial stress may affect the risk for obesity, modifying food intake and choice. A recent study suggested regulator of G-protein signaling 6 (RGS6) as a novel candidate gene for obesity in terms of reward-related feeding under stress. In this study, we tried to verify the unidentified connection between RGS6 and human obesity with psychosocial stress in a Korean population. A total of 1,462 adult subjects, who participated in the Korean Association Resource cohort project, were included for this analysis. Obesity-related traits including waist circumference, body mass index, and visceral adipose tissue were recorded. A total of 4 intronic SNPs for the RGS6 gene were used for this study. We found that interactions between SNP rs2239219 and psychosocial stress are significantly associated with abdominal obesity (p = 0.007). As risk allele of this SNP increased, prevalence of abdominal obesity under high-stress conditions gradually increased (p = 0.013). However, we found no SNPs-by-stress interaction effect on other adiposity phenotypes. This study suggests that RGS6 is closely linked to stress-induced abdominal obesity in Korean adults.

Differential expression of genes regulated in response to drought stress in diploid cotton (Gossypium arboreum) (abstract)

International Nuclear Information System (INIS)

Hussain, T.; Majeed, A.; Maqbool, A.; Hussain, S.S.; Ali, T.; Riazuddin, S.

2005-01-01

Negative effects on the Water status of plants is one of the most common and deleterious stresses experienced by wild and cultivated plants throughout the World. Our project is designed to identify, clone and characterize gene sequences regulated in response to Water stress (e.g., drought). We used the differential-display reverse transcriptase polymerase chain reaction (DD-RT- PCA) methodology to accomplish our Objectives. Structural and functional characterization of environmental stress-induced genes has contributed to a better understanding of how plants respond and adapt to different abiotic stresses. Differential display was used to compare overall difference in gene expression between draught stressed and unstressed (control) plants of diploid Cotton (Gossypium arboreum). DDRT-PCR product from stressed and unstressed samples resolved side by side on 6% PAGE to compare qualitative and quantitative difference in mRNA expression. A total of 81 primer combinations were tested. DDRT -PCR enabled us to identify differentially expressed transcripts between water stressed and non-stressed cotton seedlings. PAGE revealed a total of 347 DNA transcripts in stressed samples (New Transcripts) while 110 down regulated and 209 up regulated DNA transcripts were also recorded. Similarly. 22 DNA transcripts were identified based on the comparative study of PAGE and Agarose gel electrophoresis. These sequences showed various degree homology With draught tolerant genes in the gene bank. (author)

The endocannabinoid gene faah2a modulates stress-associated behavior in zebrafish.

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Randall G Krug

Full Text Available The ability to orchestrate appropriate physiological and behavioral responses to stress is important for survival, and is often dysfunctional in neuropsychiatric disorders that account for leading causes of global disability burden. Numerous studies have shown that the endocannabinoid neurotransmitter system is able to regulate stress responses and could serve as a therapeutic target for the management of these disorders. We used quantitative reverse transcriptase-polymerase chain reactions to show that genes encoding enzymes that synthesize (abhd4, gde1, napepld, enzymes that degrade (faah, faah2a, faah2b, and receptors that bind (cnr1, cnr2, gpr55-like endocannabinoids are expressed in zebrafish (Danio rerio. These genes are conserved in many other vertebrates, including humans, but fatty acid amide hydrolase 2 has been lost in mice and rats. We engineered transcription activator-like effector nucleases to create zebrafish with mutations in cnr1 and faah2a to test the role of these genes in modulating stress-associated behavior. We showed that disruption of cnr1 potentiated locomotor responses to hyperosmotic stress. The increased response to stress was consistent with rodent literature and served to validate the use of zebrafish in this field. Moreover, we showed for the first time that disruption of faah2a attenuated the locomotor responses to hyperosmotic stress. This later finding suggests that FAAH2 may be an important mediator of stress responses in non-rodent vertebrates. Accordingly, FAAH and FAAH2 modulators could provide distinct therapeutic options for stress-aggravated disorders.

Global Analysis of WRKY Genes and Their Response to Dehydration and Salt Stress in Soybean.

Science.gov (United States)

Song, Hui; Wang, Pengfei; Hou, Lei; Zhao, Shuzhen; Zhao, Chuanzhi; Xia, Han; Li, Pengcheng; Zhang, Ye; Bian, Xiaotong; Wang, Xingjun

2016-01-01

WRKY proteins are plant specific transcription factors involved in various developmental and physiological processes, especially in biotic and abiotic stress resistance. Although previous studies suggested that WRKY proteins in soybean (Glycine max var. Williams 82) involved in both abiotic and biotic stress responses, the global information of WRKY proteins in the latest version of soybean genome (Wm82.a2v1) and their response to dehydration and salt stress have not been reported. In this study, we identified 176 GmWRKY proteins from soybean Wm82.a2v1 genome. These proteins could be classified into three groups, namely group I (32 proteins), group II (120 proteins), and group III (24 proteins). Our results showed that most GmWRKY genes were located on Chromosome 6, while chromosome 11, 12, and 20 contained the least number of this gene family. More GmWRKY genes were distributed on the ends of chromosomes to compare with other regions. The cis-acting elements analysis suggested that GmWRKY genes were transcriptionally regulated upon dehydration and salt stress. RNA-seq data analysis indicated that three GmWRKY genes responded negatively to dehydration, and 12 genes positively responded to salt stress at 1, 6, and 12 h, respectively. We confirmed by qRT-PCR that the expression of GmWRKY47 and GmWRKY 58 genes was decreased upon dehydration, and the expression of GmWRKY92, 144 and 165 genes was increased under salt treatment.

Oroxin B selectively induces tumor-suppressive ER stress and concurrently inhibits tumor-adaptive ER stress in B-lymphoma cells for effective anti-lymphoma therapy

International Nuclear Information System (INIS)

Yang, Ping; Fu, Shilong; Cao, Zhifei; Liao, Huaidong; Huo, Zihe; Pan, Yanyan; Zhang, Gaochuan; Gao, Aidi; Zhou, Quansheng

2015-01-01

Cancer cells have both tumor-adaptive and -suppressive endoplasmic reticulum (ER) stress machineries that determine cell fate. In malignant tumors including lymphoma, constant activation of tumor-adaptive ER stress and concurrent reduction of tumor-suppressive ER stress favors cancer cell proliferation and tumor growth. Current ER stress-based anti-tumor drugs typically activate both tumor-adaptive and -suppressive ER stresses, resulting in low anti-cancer efficacy; hence, selective induction of tumor-suppressive ER stress and inhibition of tumor-adaptive ER stress are new strategies for novel anti-cancer drug discovery. Thus far, specific tumor-suppressive ER stress therapeutics have remained absent in clinical settings. In this study, we explored unique tumor-suppressive ER stress agents from the traditional Chinese medicinal herb Oroxylum indicum, and found that a small molecule oroxin B selectively induced tumor-suppressive ER stress in malignant lymphoma cells, but not in normal cells, effectively inhibited lymphoma growth in vivo, and significantly prolonged overall survival of lymphoma-xenografted mice without obvious toxicity. Mechanistic studies have revealed that the expression of key tumor-adaptive ER-stress gene GRP78 was notably suppressed by oroxin B via down-regulation of up-stream key signaling protein ATF6, while tumor-suppressive ER stress master gene DDIT3 was strikingly activated through activating the MKK3-p38 signaling pathway, correcting the imbalance between tumor-suppressive DDIT3 and tumor-adaptive GRP78 in lymphoma. Together, selective induction of unique tumor-suppressive ER stress and concurrent inhibition of tumor-adaptive ER stress in malignant lymphoma are new and feasible approaches for novel anti-lymphoma drug discovery and anti-lymphoma therapy. - Highlights: • Oroxin B selectively induces tumor-suppressive ER stress in B-lymphoma cells. • Oroxin B significantly prolonged overall survival of lymphoma-xenografted mice. �

Oroxin B selectively induces tumor-suppressive ER stress and concurrently inhibits tumor-adaptive ER stress in B-lymphoma cells for effective anti-lymphoma therapy

Energy Technology Data Exchange (ETDEWEB)

Yang, Ping; Fu, Shilong; Cao, Zhifei; Liao, Huaidong; Huo, Zihe; Pan, Yanyan; Zhang, Gaochuan; Gao, Aidi; Zhou, Quansheng, E-mail: zhouqs@suda.edu.cn

2015-10-15

Cancer cells have both tumor-adaptive and -suppressive endoplasmic reticulum (ER) stress machineries that determine cell fate. In malignant tumors including lymphoma, constant activation of tumor-adaptive ER stress and concurrent reduction of tumor-suppressive ER stress favors cancer cell proliferation and tumor growth. Current ER stress-based anti-tumor drugs typically activate both tumor-adaptive and -suppressive ER stresses, resulting in low anti-cancer efficacy; hence, selective induction of tumor-suppressive ER stress and inhibition of tumor-adaptive ER stress are new strategies for novel anti-cancer drug discovery. Thus far, specific tumor-suppressive ER stress therapeutics have remained absent in clinical settings. In this study, we explored unique tumor-suppressive ER stress agents from the traditional Chinese medicinal herb Oroxylum indicum, and found that a small molecule oroxin B selectively induced tumor-suppressive ER stress in malignant lymphoma cells, but not in normal cells, effectively inhibited lymphoma growth in vivo, and significantly prolonged overall survival of lymphoma-xenografted mice without obvious toxicity. Mechanistic studies have revealed that the expression of key tumor-adaptive ER-stress gene GRP78 was notably suppressed by oroxin B via down-regulation of up-stream key signaling protein ATF6, while tumor-suppressive ER stress master gene DDIT3 was strikingly activated through activating the MKK3-p38 signaling pathway, correcting the imbalance between tumor-suppressive DDIT3 and tumor-adaptive GRP78 in lymphoma. Together, selective induction of unique tumor-suppressive ER stress and concurrent inhibition of tumor-adaptive ER stress in malignant lymphoma are new and feasible approaches for novel anti-lymphoma drug discovery and anti-lymphoma therapy. - Highlights: • Oroxin B selectively induces tumor-suppressive ER stress in B-lymphoma cells. • Oroxin B significantly prolonged overall survival of lymphoma-xenografted mice. �

Differential gene expression during thermal stress and bleaching in the Caribbean coral Montastraea faveolata.

Science.gov (United States)

DeSalvo, M K; Voolstra, C R; Sunagawa, S; Schwarz, J A; Stillman, J H; Coffroth, M A; Szmant, A M; Medina, M

2008-09-01

The declining health of coral reefs worldwide is likely to intensify in response to continued anthropogenic disturbance from coastal development, pollution, and climate change. In response to these stresses, reef-building corals may exhibit bleaching, which marks the breakdown in symbiosis between coral and zooxanthellae. Mass coral bleaching due to elevated water temperature can devastate coral reefs on a large geographical scale. In order to understand the molecular and cellular basis of bleaching in corals, we have measured gene expression changes associated with thermal stress and bleaching using a complementary DNA microarray containing 1310 genes of the Caribbean coral Montastraea faveolata. In a first experiment, we identified differentially expressed genes by comparing experimentally bleached M. faveolata fragments to control non-heat-stressed fragments. In a second experiment, we identified differentially expressed genes during a time course experiment with four time points across 9 days. Results suggest that thermal stress and bleaching in M. faveolata affect the following processes: oxidative stress, Ca(2+) homeostasis, cytoskeletal organization, cell death, calcification, metabolism, protein synthesis, heat shock protein activity, and transposon activity. These results represent the first medium-scale transcriptomic study focused on revealing the cellular foundation of thermal stress-induced coral bleaching. We postulate that oxidative stress in thermal-stressed corals causes a disruption of Ca(2+) homeostasis, which in turn leads to cytoskeletal and cell adhesion changes, decreased calcification, and the initiation of cell death via apoptosis and necrosis.

KvLEA, a New Isolated Late Embryogenesis Abundant Protein Gene from Kosteletzkya virginica Responding to Multiabiotic Stresses

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Xiaoli Tang

2016-01-01

Full Text Available The LEA proteins are a kind of hydrophilic proteins, playing main functions in desiccation tolerance. However, their importance as a kind of stress proteins in abiotic stress is being clarified little by little. In this study we isolated, cloned, and identified the first KvLEA gene in Kosteletzkya virginica. Bioinformatic analysis showed that the protein encoded by this gene had common properties of LEA proteins and the multiple sequences alignment and phylogenetic analysis further showed that this protein had high homology with two Arabidopsis LEA proteins. Gene expression analysis revealed that this gene had a higher expression in root and it was induced obviously by salt stress. Moreover, the transcripts of KvLEA were also induced by other abiotic stresses including drought, high temperature, chilling, and ABA treatment. Among these abiotic stresses, ABA treatment brought about the biggest changes to this gene. Collectively, our research discovered a novel LEA gene and uncovered its involvement in multiabiotic stresses in K. virginica. This research not only enriched studies on LEA gene in plant but also would accelerate more studies on K. virginica in the future.

Identification of potential internal control genes for real-time PCR analysis during stress response in Pyropia haitanensis

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Wang, Xia; Feng, Jianhua; Huang, Aiyou; He, Linwen; Niu, Jianfeng; Wang, Guangce

2017-11-01

Pyropia haitanensis has prominent stress-resistance characteristics and is endemic to China. Studies into the stress responses in these algae could provide valuable information on the stress-response mechanisms in the intertidal Rhodophyta. Here, the effects of salinity and light intensity on the quantum yield of photosystem II in Py. haitanensis were investigated using pulse-amplitude-modulation fluorometry. Total RNA and genomic DNA of the samples under different stress conditions were isolated. By normalizing to the genomic DNA quantity, the RNA content in each sample was evaluated. The cDNA was synthesized and the expression levels of seven potential internal control genes were evaluated using qRT-PCR method. Then, we used geNorm, a common statistical algorithm, to analyze the qRT-PCR data of seven reference genes. Potential genes that may constantly be expressed under different conditions were selected, and these genes showed stable expression levels in samples under a salinity treatment, while tubulin, glyceraldehyde-3-phosphate dehydrogenase and actin showed stability in samples stressed by strong light. Based on the results of the pulse amplitude-modulation fluorometry, an absolute quantification was performed to obtain gene copy numbers in certain stress-treated samples. The stably expressed genes as determined by the absolute quantification in certain samples conformed to the results of the geNorm screening. Based on the results of the software analysis and absolute quantification, we proposed that elongation factor 3 and 18S ribosomal RNA could be used as internal control genes when the Py. haitanensis blades were subjected to salinity stress, and that α-tubulin and 18S ribosomal RNA could be used as the internal control genes when the stress was from strong light. In general, our findings provide a convenient reference for the selection of internal control genes when designing experiments related to stress responses in Py. haitanensis.

Environmental stress, oxytocin receptor gene (OXTR) polymorphism, and mental health following collective stress.

Science.gov (United States)

Lucas-Thompson, Rachel G; Holman, E Alison

2013-04-01

We examined whether the oxytocin receptor gene (OXTR) single nucleotide polymorphism (SNP) rs53576 genotype buffers the combined impact of negative social environments (e.g., interpersonal conflict/constraint) and economic stress on post-traumatic stress (PTS) symptoms and impaired daily functioning following collective stress (September 11th terrorist attacks). Saliva was collected by mail and used to genotype 704 respondents. Participants completed Web-based assessments of pre-9/11 mental health, acute stress 9-23 days after 9/11, the quality of social environments 1 year post-9/11, economic stress 18 months post-9/11, and PTS symptoms and impaired functioning 2 and 3 years post-9/11. Interactions between negative social environments and economic stress were examined separately based on OXTR rs53576 genotype (GG vs. any A allele). For individuals with an A allele, a negative social environment significantly increased PTS symptoms without regard to the level of economic stress experienced. However, for respondents with a GG genotype, negative social environments predicted elevated PTS symptoms only for those also experiencing high economic stress. Gender moderated associations between negative social environments, economic stress, and impaired functioning. The functioning of females was most affected by negative social environments regardless of genotype and economic stress, whereas the functioning of males was differentially susceptible to economic stress depending on OXTR genotype and negative social environments. These findings suggest that it is important to consider the combined impact of gender and ongoing stress in different domains as moderators of genetic vulnerability following collective stress. Copyright © 2013 Elsevier Inc. All rights reserved.

CRISPR Perturbation of Gene Expression Alters Bacterial Fitness under Stress and Reveals Underlying Epistatic Constraints.

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Otoupal, Peter B; Erickson, Keesha E; Escalas-Bordoy, Antoni; Chatterjee, Anushree

2017-01-20

The evolution of antibiotic resistance has engendered an impending global health crisis that necessitates a greater understanding of how resistance emerges. The impact of nongenetic factors and how they influence the evolution of resistance is a largely unexplored area of research. Here we present a novel application of CRISPR-Cas9 technology for investigating how gene expression governs the adaptive pathways available to bacteria during the evolution of resistance. We examine the impact of gene expression changes on bacterial adaptation by constructing a library of deactivated CRISPR-Cas9 synthetic devices to tune the expression of a set of stress-response genes in Escherichia coli. We show that artificially inducing perturbations in gene expression imparts significant synthetic control over fitness and growth during stress exposure. We present evidence that these impacts are reversible; strains with synthetically perturbed gene expression regained wild-type growth phenotypes upon stress removal, while maintaining divergent growth characteristics under stress. Furthermore, we demonstrate a prevailing trend toward negative epistatic interactions when multiple gene perturbations are combined simultaneously, thereby posing an intrinsic constraint on gene expression underlying adaptive trajectories. Together, these results emphasize how CRISPR-Cas9 can be employed to engineer gene expression changes that shape bacterial adaptation, and present a novel approach to synthetically control the evolution of antimicrobial resistance.

Acute hypoxia stress induced abundant differential expression genes and alternative splicing events in heart of tilapia.

Science.gov (United States)

Xia, Jun Hong; Li, Hong Lian; Li, Bi Jun; Gu, Xiao Hui; Lin, Hao Ran

2018-01-10

Hypoxia is one of the critical environmental stressors for fish in aquatic environments. Although accumulating evidences indicate that gene expression is regulated by hypoxia stress in fish, how genes undergoing differential gene expression and/or alternative splicing (AS) in response to hypoxia stress in heart are not well understood. Using RNA-seq, we surveyed and detected 289 differential expressed genes (DEG) and 103 genes that undergo differential usage of exons and splice junctions events (DUES) in heart of a hypoxia tolerant fish, Nile tilapia, Oreochromis niloticus following 12h hypoxic treatment. The spatio-temporal expression analysis validated the significant association of differential exon usages in two randomly selected DUES genes (fam162a and ndrg2) in 5 tissues (heart, liver, brain, gill and spleen) sampled at three time points (6h, 12h, and 24h) under acute hypoxia treatment. Functional analysis significantly associated the differential expressed genes with the categories related to energy conservation, protein synthesis and immune response. Different enrichment categories were found between the DEG and DUES dataset. The Isomerase activity, Oxidoreductase activity, Glycolysis and Oxidative stress process were significantly enriched for the DEG gene dataset, but the Structural constituent of ribosome and Structural molecule activity, Ribosomal protein and RNA binding protein were significantly enriched only for the DUES genes. Our comparative transcriptomic analysis reveals abundant stress responsive genes and their differential regulation function in the heart tissues of Nile tilapia under acute hypoxia stress. Our findings will facilitate future investigation on transcriptome complexity and AS regulation during hypoxia stress in fish. Copyright © 2017 Elsevier B.V. All rights reserved.

Grr1p is required for transcriptional induction of amino acid permease genes and proper transcriptional regulation of genes in carbon metabolism of Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Eckert-Boulet, Nadine; Regenberg, Birgitte; Nielsen, Jens

2005-01-01

and a grr1 Delta strain and adding citrulline in the exponential phase. Whole-genome transcription analyses were performed on samples from each cultivation, both immediately before and 30 min after citrulline addition. Transcriptional induction of the AAP genes AGP1, BAP2, BAP3, DIP5, GNP1 and TAT1 is fully...

Genes and co-expression modules common to drought and bacterial stress responses in Arabidopsis and rice.

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Rafi Shaik

Full Text Available Plants are simultaneously exposed to multiple stresses resulting in enormous changes in the molecular landscape within the cell. Identification and characterization of the synergistic and antagonistic components of stress response mechanisms contributing to the cross talk between stresses is of high priority to explore and enhance multiple stress responses. To this end, we performed meta-analysis of drought (abiotic, bacterial (biotic stress response in rice and Arabidopsis by analyzing a total of 386 microarray samples belonging to 20 microarray studies and identified approximately 3100 and 900 DEGs in rice and Arabidopsis, respectively. About 38.5% (1214 and 28.7% (272 DEGs were common to drought and bacterial stresses in rice and Arabidopsis, respectively. A majority of these common DEGs showed conserved expression status in both stresses. Gene ontology enrichment analysis clearly demarcated the response and regulation of various plant hormones and related biological processes. Fatty acid metabolism and biosynthesis of alkaloids were upregulated and, nitrogen metabolism and photosynthesis was downregulated in both stress conditions. WRKY transcription family genes were highly enriched in all upregulated gene sets while 'CO-like' TF family showed inverse relationship of expression between drought and bacterial stresses. Weighted gene co-expression network analysis divided DEG sets into multiple modules that show high co-expression and identified stress specific hub genes with high connectivity. Detection of consensus modules based on DEGs common to drought and bacterial stress revealed 9 and 4 modules in rice and Arabidopsis, respectively, with conserved and reversed co-expression patterns.

Dynamic regulation of cerebral DNA repair genes by psychological stress

DEFF Research Database (Denmark)

Forsberg, Kristin; Aalling, Nadia; Wörtwein, Gitta

2015-01-01

Neuronal genotoxic insults from oxidative stress constitute a putative molecular link between stress and depression on the one hand, and cognitive dysfunction and dementia risk on the other. Oxidative modifications to DNA are repaired by specific enzymes; a process that plays a critical role...... restraint stress (6h/day) or daily handling (controls), and sacrificed after 1, 7 or 21 stress sessions. The mRNA expression of seven genes (Ogg1, Ape1, Ung1, Neil1, Xrcc1, Ercc1, Nudt1) involved in the repair of oxidatively damaged DNA was determined by quantitative real time polymerase chain reaction...

Transgenerational stress memory is not a general response in Arabidopsis.

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Ales Pecinka

Full Text Available Adverse conditions can trigger DNA damage as well as DNA repair responses in plants. A variety of stress factors are known to stimulate homologous recombination, the most accurate repair pathway, by increasing the concentration of necessary enzymatic components and the frequency of events. This effect has been reported to last into subsequent generations not exposed to the stress. To establish a basis for a genetic analysis of this transgenerational stress memory, a broad range of treatments was tested for quantitative effects on homologous recombination in the progeny. Several Arabidopsis lines, transgenic for well-established recombination traps, were exposed to 10 different physical and chemical stress treatments, and scored for the number of somatic homologous recombination (SHR events in the treated generation as well as in the two subsequent generations that were not treated. These numbers were related to the expression level of genes involved in homologous recombination and repair. SHR was enhanced after the majority of treatments, confirming previous data and adding new effective stress types, especially interference with chromatin. Compounds that directly modify DNA stimulated SHR to values exceeding previously described induction rates, concomitant with an induction of genes involved in SHR. In spite of the significant stimulation in the stressed generations, the two subsequent non-treated generations only showed a low and stochastic increase in SHR that did not correlate with the degree of stimulation in the parental plants. Transcripts coding for SHR enzymes generally returned to pre-treatment levels in the progeny. Thus, transgenerational effects on SHR frequency are not a general response to abiotic stress in Arabidopsis and may require special conditions.

AOX1-Subfamily Gene Members in Olea europaea cv. “Galega Vulgar”—Gene Characterization and Expression of Transcripts during IBA-Induced in Vitro Adventitious Rooting

Science.gov (United States)

Lousa, Diana; M. Soares, Cláudio; Santos Macedo, Elisete; Arnholdt-Schmitt, Birgit

2018-01-01

Propagation of some Olea europaea L. cultivars is strongly limited due to recalcitrant behavior in adventitious root formation by semi-hardwood cuttings. One example is the cultivar ”Galega vulgar”. The formation of adventitious roots is considered a morphological response to stress. Alternative oxidase (AOX) is the terminal oxidase of the alternative pathway of the plant mitochondrial electron transport chain. This enzyme is well known to be induced in response to several biotic and abiotic stress situations. This work aimed to characterize the alternative oxidase 1 (AOX1)-subfamily in olive and to analyze the expression of transcripts during the indole-3-butyric acid (IBA)-induced in vitro adventitious rooting (AR) process. OeAOX1a (acc. no. MF410318) and OeAOX1d (acc. no. MF410319) were identified, as well as different transcript variants for both genes which resulted from alternative polyadenylation events. A correlation between transcript accumulation of both OeAOX1a and OeAOX1d transcripts and the three distinct phases (induction, initiation, and expression) of the AR process in olive was observed. Olive AOX1 genes seem to be associated with the induction and development of adventitious roots in IBA-treated explants. A better understanding of the molecular mechanisms underlying the stimulus needed for the induction of adventitious roots may help to develop more targeted and effective rooting induction protocols in order to improve the rooting ability of difficult-to-root cultivars. PMID:29462998

Induction of Mrp3 and Mrp4 transporters during acetaminophen hepatotoxicity is dependent on Nrf2

International Nuclear Information System (INIS)

Aleksunes, Lauren M.; Slitt, Angela L.; Maher, Jonathan M.; Augustine, Lisa M.; Goedken, Michael J.; Chan, Jefferson Y.; Cherrington, Nathan J.; Klaassen, Curtis D.; Manautou, Jose E.

2008-01-01

The transcription factor NFE2-related factor 2 (Nrf2) mediates detoxification and antioxidant gene transcription following electrophile exposure and oxidative stress. Mice deficient in Nrf2 (Nrf2-null) are highly susceptible to acetaminophen (APAP) hepatotoxicity and exhibit lower basal and inducible expression of cytoprotective genes, including NADPH quinone oxidoreductase 1 (Nqo1) and glutamate cysteine ligase (catalytic subunit, or Gclc). Administration of toxic APAP doses to C57BL/6J mice generates electrophilic stress and subsequently increases levels of hepatic Nqo1, Gclc and the efflux multidrug resistance-associated protein transporters 1-4 (Mrp1-4). It was hypothesized that induction of hepatic Mrp1-4 expression following APAP is Nrf2 dependent. Plasma and livers from wild-type (WT) and Nrf2-null mice were collected 4, 24 and 48 h after APAP. As expected, hepatotoxicity was greater in Nrf2-null compared to WT mice. Gene and protein expression of Mrp1-4 and the Nrf2 targets, Nqo1 and Gclc, was measured. Induction of Nqo1 and Gclc mRNA and protein after APAP was dependent on Nrf2 expression. Similarly, APAP treatment increased hepatic Mrp3 and Mrp4 mRNA and protein in WT, but not Nrf2-null mice. Mrp1 was induced in both genotypes after APAP, suggesting that elevated expression of this transporter was independent of Nrf2. Mrp2 was not induced in either genotype at the mRNA or protein levels. These results show that Nrf2 mediates induction of Mrp3 and Mrp4 after APAP but does not affect Mrp1 or Mrp2. Thus coordinated regulation of detoxification enzymes and transporters by Nrf2 during APAP hepatotoxicity is a mechanism by which hepatocytes may limit intracellular accumulation of potentially toxic chemicals

Gene expression profiles during short-term heat stress; branching vs. massive Scleractinian corals of the Red Sea

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Keren Maor-Landaw

2016-03-01

Full Text Available It is well-established that there is a hierarchy of susceptibilities amongst coral genera during heat-stress. However, molecular mechanisms governing these differences are still poorly understood. Here we explored if specific corals possessing different morphologies and different susceptibilities to heat stress may manifest varied gene expression patterns. We examined expression patterns of seven genes in the branching corals Stylophora pistillata and Acropora eurystoma and additionally in the massive robust coral, Porites sp. The tested genes are representatives of key cellular processes occurring during heat-stress in Cnidaria: oxidative stress, ER stress, energy metabolism, DNA repair and apoptosis. Varied response to the heat-stress, in terms of visual coral paling, algal maximum quantum yield and host gene expression was evident in the different growth forms. The two branching corals exhibited similar overall responses that differed from that of the massive coral. A. eurystoma that is considered as a susceptible species did not bleach in our experiment, but tissue sloughing was evident at 34 °C. Interestingly, in this species redox regulation genes were up-regulated at the very onset of the thermal challenge. In S. pistillata, bleaching was evident at 34 °C and most of the stress markers were already up-regulated at 32 °C, either remaining highly expressed or decreasing when temperatures reached 34 °C. The massive Porites species displayed severe bleaching at 32 °C but stress marker genes were only significantly elevated at 34 °C. We postulate that by expelling the algal symbionts from Porites tissues, oxidation damages are reduced and stress genes are activated only at a progressed stage. The differential gene expression responses exhibited here can be correlated with the literature well-documented hierarchy of susceptibilities amongst coral morphologies and genera in Eilat’s coral reef.

Improvement of stress tolerance and leavening ability under multiple baking-associated stress conditions by overexpression of the SNR84 gene in baker's yeast.

Science.gov (United States)

Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Feng, Bing; Xiao, Dong-Guang

2015-03-16

During the bread-making process, industrial baker's yeast cells are exposed to multiple baking-associated stresses, such as elevated high-temperature, high-sucrose and freeze-thaw stresses. There is a high demand for baker's yeast strains that could withstand these stresses with high leavening ability. The SNR84 gene encodes H/ACA snoRNA (small nucleolar RNA), which is known to be involved in pseudouridylation of the large subunit rRNA. However, the function of the SNR84 gene in baker's yeast coping with baking-associated stresses remains unclear. In this study, we explored the effect of SNR84 overexpression on baker's yeast which was exposed to high-temperature, high-sucrose and freeze-thaw stresses. These results suggest that overexpression of the SNR84 gene conferred tolerance of baker's yeast cells to high-temperature, high-sucrose and freeze-thaw stresses and enhanced their leavening ability in high-sucrose and freeze-thaw dough. These findings could provide a valuable insight for breeding of novel stress-resistant baker's yeast strains that are useful for baking. Copyright © 2015 Elsevier B.V. All rights reserved.

Silicon Regulates Potential Genes Involved in Major Physiological Processes in Plants to Combat Stress

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Abinaya Manivannan

2017-08-01

Full Text Available Silicon (Si, the quasi-essential element occurs as the second most abundant element in the earth's crust. Biological importance of Si in plant kingdom has become inevitable particularly under stressed environment. In general, plants are classified as high, medium, and low silicon accumulators based on the ability of roots to absorb Si. The uptake of Si directly influence the positive effects attributed to the plant but Si supplementation proves to mitigate stress and recover plant growth even in low accumulating plants like tomato. The application of Si in soil as well as soil-less cultivation systems have resulted in the enhancement of quantitative and qualitative traits of plants even under stressed environment. Silicon possesses several mechanisms to regulate the physiological, biochemical, and antioxidant metabolism in plants to combat abiotic and biotic stresses. Nevertheless, very few reports are available on the aspect of Si-mediated molecular regulation of genes with potential role in stress tolerance. The recent advancements in the era of genomics and transcriptomics have opened an avenue for the determination of molecular rationale associated with the Si amendment to the stress alleviation in plants. Therefore, the present endeavor has attempted to describe the recent discoveries related to the regulation of vital genes involved in photosynthesis, transcription regulation, defense, water transport, polyamine synthesis, and housekeeping genes during abiotic and biotic stress alleviation by Si. Furthermore, an overview of Si-mediated modulation of multiple genes involved in stress response pathways such as phenylpropanoid pathway, jasmonic acid pathway, ABA-dependent or independent regulatory pathway have been discussed in this review.

Exposure of Jurkat cells to bis (tri-n-butyltin) oxide (TBTO) induces transcriptomics changes indicative for ER- and oxidative stress, T cell activation and apoptosis

International Nuclear Information System (INIS)

Katika, Madhumohan R.; Hendriksen, Peter J.M.; Loveren, Henk van; Peijnenburg, Ad

2011-01-01

Tributyltin oxide (TBTO) is an organotin compound that is widely used as a biocide in agriculture and as an antifouling agent in paints. TBTO is toxic for many cell types, particularly immune cells. The present study aimed to identify the effects of TBTO on the human T lymphocyte cell line Jurkat. Cells were treated with 0.2 and 0.5 μM TBTO for 3, 6, 12 and 24 h and then subjected to whole genome gene expression microarray analysis. The biological interpretation of the gene expression profiles revealed that endoplasmic reticulum (ER) stress is among the earliest effects of TBTO. Simultaneously or shortly thereafter, oxidative stress, activation of NFKB and NFAT, T cell activation, and apoptosis are induced. The effects of TBTO on genes involved in ER stress, NFAT pathway, T cell activation and apoptosis were confirmed by qRT-PCR. Activation and nuclear translocation of NFATC1 and the oxidative stress response proteins NRF2 and KEAP1 were confirmed by immunocytology. Taking advantage of previously published microarray data, we demonstrated that the induction of ER stress, oxidative stress, T cell activation and apoptosis by TBTO is not unique for Jurkat cells but does also occur in mouse thymocytes both ex vivo and in vivo and rat thymocytes ex vivo. We propose that the induction of ER stress leading to a T cell activation response is a major factor in the higher sensitivity of immune cells above other types of cells for TBTO. - Research Highlights: → The human T lymphocyte cell line Jurkat was exposed to TBTO. → Whole-genome microarray experiments were performed. → Data analysis revealed the induction of ER stress and activation of NFAT and NFKB. → Exposure to TBTO also led to T cell activation, oxidative stress and apoptosis.

Molecular characterization and expression analysis of a heat shock protein 90 gene from disk abalone (Haliotis discus).

Science.gov (United States)

Wang, Ning; Whang, Ilson; Lee, Jae-Seong; Lee, Jehee

2011-06-01

Heat shock protein 90s (hsp90s) are chaperones that contribute to the proper folding of cellular proteins and help animals cope with the cellular protein damages in stress conditions. In this study, an hsp90 gene was isolated from disc abalone (Haliotis discus). The complete nucleotide sequence of the hsp90 gene contains an open reading frame of 2,184 base pairs, encoding an 84 kDa protein. Disk abalone hsp90 shares high sequence similarity with other hsp90 family proteins. Although the phylogenetic analysis did not classify it into the hsp90α group, the inductivity of this gene was confirmed by heat shock and lipopolysaccharide (LPS) challenge test. Disk abalone hsp90 gene displayed a rapid and reversible induction response to both an exposure of typical heat shock and the LPS challenge. Once given the sublethal heat shock treatment, the transcription of disk abalone hsp90 gene was significantly up-regulated. With a recovery of 12 h, the transcription of disk abalone hsp90 gene gradually attenuated to the control level. These observations reflected the feedback regulation of abalone heat shock responses faithfully. In response to LPS challenge, the transcription of disk abalone hsp90 gene was significantly increased within 2 h and it approached maximum induction at 4 h later and recovered finally the reference level in 24 h. Take all together, the cloning and expression analysis of disk abalone hsp90 gene provided useful molecular information of abalone responses in stress conditions and potential ways to monitor the chronic stressors in abalone culture environments and diagnose the animal health status.

In-silico identification and characterization of organic and inorganic chemical stress responding genes in yeast (Saccharomyces cerevisiae).

Science.gov (United States)

Barozai, Muhammad Younas Khan; Bashir, Farrukh; Muzaffar, Shafia; Afzal, Saba; Behlil, Farida; Khan, Muzaffar

2014-10-15

To study the life processes of all eukaryotes, yeast (Saccharomyces cerevisiae) is a significant model organism. It is also one of the best models to study the responses of genes at transcriptional level. In a living organism, gene expression is changed by chemical stresses. The genes that give response to chemical stresses will provide good source for the strategies in engineering and formulating mechanisms which are chemical stress resistant in the eukaryotic organisms. The data available through microarray under the chemical stresses like lithium chloride, lactic acid, weak organic acids and tomatidine were studied by using computational tools. Out of 9335 yeast genes, 388 chemical stress responding genes were identified and characterized under different chemical stresses. Some of these are: Enolases 1 and 2, heat shock protein-82, Yeast Elongation Factor 3, Beta Glucanase Protein, Histone H2A1 and Histone H2A2 Proteins, Benign Prostatic Hyperplasia, ras GTPase activating protein, Establishes Silent Chromatin protein, Mei5 Protein, Nondisjunction Protein and Specific Mitogen Activated Protein Kinase. Characterization of these genes was also made on the basis of their molecular functions, biological processes and cellular components. Copyright © 2014 Elsevier B.V. All rights reserved.

Gene expression during different periods of the handling-stress response in Pampus argenteus

Science.gov (United States)

Sun, Peng; Tang, Baojun; Yin, Fei

2017-11-01

Common aquaculture practices subject fish to a variety of acute and chronic stressors. Such stressors are inherent in aquaculture production but can adversely affect survival, growth, immune response, reproductive capacity, and behavior. Understanding the biological mechanisms underlying stress responses helps with methods to alleviate the negative effects through better aquaculture practices, resulting in improved animal welfare and production efficiency. In the present study, transcriptome sequencing of liver and kidney was performed in silver pomfret (Pampus argenteus) subjected to handling stress versus controls. A total of 162.19 million clean reads were assembled to 30 339 unigenes. The quality of the assembly was high, with an N50 length of 2 472 bases. For function classification and pathway assignment, the unigenes were categorized into three GO (gene ontology) categories, twenty-six clusters of eggNOG (evolutionary genealogy of genes: non-supervised orthologous groups) function categories, and thirty-eight KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways. Stress affected different functional groups of genes in the tissues studied. Differentially expressed genes were mainly involved in metabolic pathways (carbohydrate metabolism, lipid metabolism, amino-acid metabolism, uptake of cofactors and vitamins, and biosynthesis of other secondary metabolites), environmental information processing (signaling molecules and their interactions), organismal systems (endocrine system, digestive system), and disease (immune, neurodegenerative, endocrine and metabolic diseases). This is the first reported analysis of genome-wide transcriptome in P. argenteus, and the findings expand our understanding of the silver pomfret genome and gene expression in association with stress. The results will be useful to future analyses of functional genes and studies of healthy artificial breeding in P. argenteus and other related fish species.

Expression of genes involved in oxidative stress response in colonies of the ascidian Botryllus schlosseri exposed to various environmental conditions

Science.gov (United States)

Tasselli, Stefano; Ballin, Francesca; Franchi, Nicola; Fabbri, Elena; Ballarin, Loriano

2017-03-01

Environmental stress conditions are ultimately related to the induction of oxidative stress in organisms, as a consequence of an increased production of reactive oxygen species (ROS). This could be exploited to study sub-lethal effects induced by the environment in the organisms. In the present work, we evaluate the possibility to use the colonial ascidian Botryllus schlosseri as a bioindicator, to assess the environmental quality in the Lagoon of Venice. Three colony batches were immersed, for 22 days, at two sites (1 and 2) with different grades of hydrodynamics and anthropogenic impact and physico-chemical features of seawater; a control batch was kept in a large tank with continuous seawater flow at the Marine Station of the Department of Biology, University of Padova, in Chioggia (site 3). Seawater at site 2 had higher pH and temperature than site 1. Colonies were then retrieved, their mRNA was extracted and the level of transcription of genes involved in oxidative stress response (glutathione synthase, γ-glutamyl-cysteine ligase, modulatory subunit, two isoforms of glutathione peroxidases and Cu/Zn superoxide dismutase) was evaluated. In colonies from sites 1 and 2, most genes showed significantly increased transcriptional levels with respect to control values. Spectrophotometric analyses of colony homogenates revealed that the enzymatic activity of superoxide dismutase and catalase was higher in colonies from site 2 as compared to site 1, allowing us to speculate that colonies in site 2 were under higher stress level than those in site 1. Overall, we can conclude that B. schlosseri seems a good indicator of the ecological status of the Lagoon environment, within a range of pH and temperature in which colonies are used to live.

Down-regulation of SMT3A gene expression in association with DNA synthesis induction after X-ray irradiation in nevoid basal cell carcinoma syndrome (NBCCS) cells

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Sugaya, Shigeru; Nakanishi, Hiroshi; Tanzawa, Hideki; Sugita, Katsuo; Kita, Kazuko; Suzuki, Nobuo

2005-01-01

Fibroblast cells derived from nevoid basal carcinoma syndrome (NBCCS) patients show increased levels of DNA synthesis after X-ray irradiation. Genes, whose expression is modulated in association with the DNA synthesis induction, were searched by using PCR-based mRNA differential display analysis in one of the NBCCS cell lines, NBCCS1 cells. Decreased levels of SMT3A gene expression were found in X-ray-irradiated NBCCS1 cells. This decrease was also shown by RT-PCR analysis in another cell line, NBCCS3 cells. In addition to NBCCS cells, normal fibroblast cells showed the DNA synthesis induction after X-ray irradiation when they were treated with antisense oligonucleotides (AO) for SMT3A. However, treatment of normal fibroblasts with the random oligonucleotides (RO) resulted in decreased levels of DNA synthesis after X-ray irradiation. Thus, down-regulation of SMT3A gene expression may be involved in the DNA synthesis induction after X-ray irradiation in the NBCCS cells at least tested

Down-regulation of SMT3A gene expression in association with DNA synthesis induction after X-ray irradiation in nevoid basal cell carcinoma syndrome (NBCCS) cells

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Sugaya, Shigeru [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Nakanishi, Hiroshi [Department of Clinical Molecular Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Tanzawa, Hideki [Department of Clinical Molecular Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Sugita, Katsuo [Department of Clinical Medicine, Faculty of Education, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522 (Japan); Kita, Kazuko [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Suzuki, Nobuo [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan)]. E-mail: nobuo@faculty.chiba-u.jp

2005-10-15

Fibroblast cells derived from nevoid basal carcinoma syndrome (NBCCS) patients show increased levels of DNA synthesis after X-ray irradiation. Genes, whose expression is modulated in association with the DNA synthesis induction, were searched by using PCR-based mRNA differential display analysis in one of the NBCCS cell lines, NBCCS1 cells. Decreased levels of SMT3A gene expression were found in X-ray-irradiated NBCCS1 cells. This decrease was also shown by RT-PCR analysis in another cell line, NBCCS3 cells. In addition to NBCCS cells, normal fibroblast cells showed the DNA synthesis induction after X-ray irradiation when they were treated with antisense oligonucleotides (AO) for SMT3A. However, treatment of normal fibroblasts with the random oligonucleotides (RO) resulted in decreased levels of DNA synthesis after X-ray irradiation. Thus, down-regulation of SMT3A gene expression may be involved in the DNA synthesis induction after X-ray irradiation in the NBCCS cells at least tested.

The Role of Tomato WRKY Genes in Plant Responses to Combined Abiotic and Biotic Stresses

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Yuling Bai

2018-06-01

Full Text Available In the field, plants constantly face a plethora of abiotic and biotic stresses that can impart detrimental effects on plants. In response to multiple stresses, plants can rapidly reprogram their transcriptome through a tightly regulated and highly dynamic regulatory network where WRKY transcription factors can act as activators or repressors. WRKY transcription factors have diverse biological functions in plants, but most notably are key players in plant responses to biotic and abiotic stresses. In tomato there are 83 WRKY genes identified. Here we review recent progress on functions of these tomato WRKY genes and their homologs in other plant species, such as Arabidopsis and rice, with a special focus on their involvement in responses to abiotic and biotic stresses. In particular, we highlight WRKY genes that play a role in plant responses to a combination of abiotic and biotic stresses.

Hit-and-run stimulation: a novel concept to reactivate latent HIV-1 infection without cytokine gene induction.

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Wolschendorf, Frank; Duverger, Alexandra; Jones, Jennifer; Wagner, Frederic H; Huff, Jason; Benjamin, William H; Saag, Michael S; Niederweis, Michael; Kutsch, Olaf

2010-09-01

Current antiretroviral therapy (ART) efficiently controls HIV-1 replication but fails to eradicate the virus. Even after years of successful ART, HIV-1 can conceal itself in a latent state in long-lived CD4(+) memory T cells. From this latent reservoir, HIV-1 rebounds during treatment interruptions. Attempts to therapeutically eradicate this viral reservoir have yielded disappointing results. A major problem with previously utilized activating agents is that at the concentrations required for efficient HIV-1 reactivation, these stimuli trigger high-level cytokine gene expression (hypercytokinemia). Therapeutically relevant HIV-1-reactivating agents will have to trigger HIV-1 reactivation without the induction of cytokine expression. We present here a proof-of-principle study showing that this is a possibility. In a high-throughput screening effort, we identified an HIV-1-reactivating protein factor (HRF) secreted by the nonpathogenic bacterium Massilia timonae. In primary T cells and T-cell lines, HRF triggered a high but nonsustained peak of nuclear factor kappa B (NF-kappaB) activity. While this short NF-kappaB peak potently reactivated latent HIV-1 infection, it failed to induce gene expression of several proinflammatory NF-kappaB-dependent cellular genes, such as those for tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8), and gamma interferon (IFN-gamma). Dissociation of cellular and viral gene induction was achievable, as minimum amounts of Tat protein, synthesized following application of a short NF-kappaB pulse, triggered HIV-1 transactivation and subsequent self-perpetuated HIV-1 expression. In the absence of such a positive feedback mechanism, cellular gene expression was not sustained, suggesting that strategies modulating the NF-kappaB activity profile could be used to selectively trigger HIV-1 reactivation.

Functional Characterization of Waterlogging and Heat Stresses Tolerance Gene Pyruvate decarboxylase 2 from Actinidia deliciosa

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Hui-Ting Luo

2017-11-01

Full Text Available A previous report showed that both Pyruvate decarboxylase (PDC genes were significantly upregulated in kiwifruit after waterlogging treatment using Illumina sequencing technology, and that the kiwifruit AdPDC1 gene was required during waterlogging, but might not be required during other environmental stresses. Here, the function of another PDC gene, named AdPDC2, was analyzed. The expression of the AdPDC2 gene was determined using qRT-PCR, and the results showed that the expression levels of AdPDC2 in the reproductive organs were much higher than those in the nutritive organs. Waterlogging, NaCl, and heat could induce the expression of AdPDC2. Overexpression of kiwifruit AdPDC2 in transgenic Arabidopsis enhanced resistance to waterlogging and heat stresses in five-week-old seedlings, but could not enhance resistance to NaCl and mannitol stresses at the seed germination stage and in early seedlings. These results suggested that the kiwifruit AdPDC2 gene may play an important role in waterlogging resistance and heat stresses in kiwifruit.

The Tyrosyl-DNA Phosphodiesterase 1β (Tdp1β Gene Discloses an Early Response to Abiotic Stresses

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Maria Elisa Sabatini

2017-11-01

Full Text Available Tyrosyl-DNA phosphodiesterase 1 (Tdp1 is involved in DNA repair pathways as it mends the topoisomerase I—DNA covalent complexes. In plants, a small Tdp1 gene family, composed by Tdp1α and Tdp1β genes, was identified, but the roles of these genes in abiotic stress responses are not fully understood. To investigate their specific stress response patterns, the present study made use of bioinformatic and molecular tools to look into the Tdp1β gene function, so far described only in the plant kingdom, and compare it with Tdp1α gene coding for the canonical, highly conserved α isoform. The expression profiles of Tdp1α and Tdp1β genes were examined under abiotic stress conditions (cold, heat, high osmolarity, salt, and UV-B in two model species, Arabidopsis thaliana and Medicago truncatula. The two isoforms of topoisomerase I (TOP1α and TOP1β were also taken into consideration in view of their known roles in DNA metabolism and cell proliferation. Data relative to gene expression in Arabidopsis were retrieved from the AtGenExpress microarray dataset, while quantitative Real-Time PCR was carried out to evaluate the stress response in M. truncatula cell cultures. These analyses revealed that Tdp1β gene expression was enhanced during the first hour of treatment, whereas Tdp1α enhanced expression succeeded at subsequent timepoints. In agreement with the gene-specific responses to abiotic stress conditions, the promoter regions of Tdp1α and Tdp1β genes are well equipped with stress-related cis-elements. An in-depth bioinformatic characterization of the HIRAN motif, a distinctive feature of the Tdp1β protein, showed its wide distribution in chromatin remodeling and DNA repair proteins. The reported data suggests that Tdp1β functions in the early response to abiotic stresses.

Analysis of global gene expression in Brachypodium distachyon reveals extensive network plasticity in response to abiotic stress.

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Henry D Priest

Full Text Available Brachypodium distachyon is a close relative of many important cereal crops. Abiotic stress tolerance has a significant impact on productivity of agriculturally important food and feedstock crops. Analysis of the transcriptome of Brachypodium after chilling, high-salinity, drought, and heat stresses revealed diverse differential expression of many transcripts. Weighted Gene Co-Expression Network Analysis revealed 22 distinct gene modules with specific profiles of expression under each stress. Promoter analysis implicated short DNA sequences directly upstream of module members in the regulation of 21 of 22 modules. Functional analysis of module members revealed enrichment in functional terms for 10 of 22 network modules. Analysis of condition-specific correlations between differentially expressed gene pairs revealed extensive plasticity in the expression relationships of gene pairs. Photosynthesis, cell cycle, and cell wall expression modules were down-regulated by all abiotic stresses. Modules which were up-regulated by each abiotic stress fell into diverse and unique gene ontology GO categories. This study provides genomics resources and improves our understanding of abiotic stress responses of Brachypodium.

Source-Related Effects of Wastewater on Transcription Factor (AhR, CAR and PXR-Mediated Induction of Gene Expression in Cultured Rat Hepatocytes and Their Association with the Prevalence of Antimicrobial-Resistant Escherichia coli.

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Keerthi S Guruge

Full Text Available Extracts of wastewater collected from 4 sewage treatment plants (STPs receiving effluents from different sources in South India were investigated for their levels of transcription factor-mediated gene induction in primary cultured rat hepatocytes. In addition, the relation between gene induction levels and the prevalence of antimicrobial-resistant Escherichia coli (E. coli in wastewater was examined. STP-3, which treats only hospital wastewater, exhibited significantly greater induction potency of all 6 drug metabolizing cytochrome P450 (CYP genes examined, CYP1A1, 1A2, 1B1, 2B15, 3A1, and 3A2, whereas the wastewater at STP-1, which exclusively receives domestic sewage, showed significantly diminished levels of induction of 3 CYP genes when compared to the levels of CYP induction at STP-2, which receives mixed wastewater. Samples collected during the monsoon season showed a significantly altered gene induction capacity compared to that of samples from the pre-monsoon period. The data suggest that the toxicity of wastewater in STPs was not significantly diminished during the treatment process. The chemical-gene interaction data predicted that a vast number of chemicals present in the wastewater would stimulate the genes studied in the rat hepatocytes. The multivariable logistic regression analysis demonstrated that the prevalence of isolates resistant to cefotaxime, imipenem and streptomycin was significantly correlated with the levels of induction of at least three CYP-isozymes in STP wastewater. In addition, the resistance of isolates in treatment plants was not altered by the treatment steps, whereas the sampling season did have an impact on the resistance to specific antimicrobials. The identification of receptor-mediated gene regulation capacities offers important data not limited to the (synergistic physiological role of chemicals in biological systems but may provide new insight into the link between the effects of known/unknown drugs and

Heat Stress and Lipopolysaccharide Stimulation of Chicken Macrophage-Like Cell Line Activates Expression of Distinct Sets of Genes.

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Anna Slawinska

Full Text Available Acute heat stress requires immediate adjustment of the stressed individual to sudden changes of ambient temperatures. Chickens are particularly sensitive to heat stress due to development of insufficient physiological mechanisms to mitigate its effects. One of the symptoms of heat stress is endotoxemia that results from release of the lipopolysaccharide (LPS from the guts. Heat-related cytotoxicity is mitigated by the innate immune system, which is comprised mostly of phagocytic cells such as monocytes and macrophages. The objective of this study was to analyze the molecular responses of the chicken macrophage-like HD11 cell line to combined heat stress and lipopolysaccharide treatment in vitro. The cells were heat-stressed and then allowed a temperature-recovery period, during which the gene expression was investigated. LPS was added to the cells to mimic the heat-stress-related endotoxemia. Semi high-throughput gene expression analysis was used to study a gene panel comprised of heat shock proteins, stress-related genes, signaling molecules and immune response genes. HD11 cell line responded to heat stress with increased mRNA abundance of the HSP25, HSPA2 and HSPH1 chaperones as well as DNAJA4 and DNAJB6 co-chaperones. The anti-apoptotic gene BAG3 was also highly up-regulated, providing evidence that the cells expressed pro-survival processes. The immune response of the HD11 cell line to LPS in the heat stress environment (up-regulation of CCL4, CCL5, IL1B, IL8 and iNOS was higher than in thermoneutral conditions. However, the peak in the transcriptional regulation of the immune genes was after two hours of temperature-recovery. Therefore, we propose the potential influence of the extracellular heat shock proteins not only in mitigating effects of abiotic stress but also in triggering the higher level of the immune responses. Finally, use of correlation networks for the data analysis aided in discovering subtle differences in the gene

Reactive oxygen species induced by heat stress during grain filling of rice (Oryza sativa L.) are involved in occurrence of grain chalkiness.

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Suriyasak, Chetphilin; Harano, Keisuke; Tanamachi, Koichiro; Matsuo, Kazuhiro; Tamada, Aina; Iwaya-Inoue, Mari; Ishibashi, Yushi

2017-09-01

Heat stress during grain filling increases rice grain chalkiness due to increased activity of α-amylase, which hydrolyzes starch. In rice and barley seeds, reactive oxygen species (ROS) produced after imbibition induce α-amylase activity via regulation of gibberellin (GA) and abscisic acid (ABA) levels during seed germination. Here, we examined whether ROS is involved in induction of grain chalkiness by α-amylase in developing rice grains under heat stress. To elucidate the role of ROS in grain chalkiness, we grew post-anthesis rice plants (Oryza sativa L. cv. Koshihikari) under control (25°C) or heat stress (30°C) conditions with or without antioxidant (dithiothreitol) treatment. The developing grains were analyzed for expression of NADPH oxidases, GA biosynthesis genes (OsGA3ox1, OsGA20ox1), ABA catabolism genes (OsABA8'OH1, OsABA8'OH2) and an α-amylase gene (OsAmy3E), endogenous H 2 O 2 content and the grain quality. In grains exposed to heat stress, the expression of NADPH oxidase genes (especially, OsRbohB, OsRbohD, OsRbohF and OsRbohI) and the ROS content increased. Heat stress also increased the expression of OsGA3ox1, OsGA20ox1, OsABA8'OH1, OsABA8'OH2 and OsAmy3E. On the other hand, dithiothreitol treatment reduced the effects of heat stress on the expression of these genes and significantly reduced grain chalkiness induced by heat stress. These results suggest that, similar to cereal seed germination mechanism, ROS produced under heat stress is involved in α-amylase induction in maturating rice grains through GA/ABA metabolism, and consequently caused grain chalkiness. Copyright © 2017 Elsevier GmbH. All rights reserved.

Connections between Transcription Downstream of Genes and cis-SAGe Chimeric RNA.

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Chwalenia, Katarzyna; Qin, Fujun; Singh, Sandeep; Tangtrongstittikul, Panjapon; Li, Hui

2017-11-22

cis-Splicing between adjacent genes (cis-SAGe) is being recognized as one way to produce chimeric fusion RNAs. However, its detail mechanism is not clear. Recent study revealed induction of transcriptions downstream of genes (DoGs) under osmotic stress. Here, we investigated the influence of osmotic stress on cis-SAGe chimeric RNAs and their connection to DoGs. We found,the absence of induction of at least some cis-SAGe fusions and/or their corresponding DoGs at early time point(s). In fact, these DoGs and their cis-SAGe fusions are inversely correlated. This negative correlation was changed to positive at a later time point. These results suggest a direct competition between the two categories of transcripts when total pool of readthrough transcripts is limited at an early time point. At a later time point, DoGs and corresponding cis-SAGe fusions are both induced, indicating that total readthrough transcripts become more abundant. Finally, we observed overall enhancement of cis-SAGe chimeric RNAs in KCl-treated samples by RNA-Seq analysis.

Altered Stress-Induced Regulation of Genes in Monocytes in Adults with a History of Childhood Adversity.

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Schwaiger, Marion; Grinberg, Marianna; Moser, Dirk; Zang, Johannes C S; Heinrichs, Markus; Hengstler, Jan G; Rahnenführer, Jörg; Cole, Steve; Kumsta, Robert

2016-09-01

Exposure to serious or traumatic events early in life can lead to persistent alterations in physiological stress response systems, including enhanced cross talk between the neuroendocrine and immune system. These programming effects may be mechanistically involved in mediating the effects of adverse childhood experience on disease risk in adulthood. We investigated hormonal and genome-wide mRNA expression responses in monocytes to acute stress exposure, in a sample of healthy adults (n=30) with a history of early childhood adversity, and a control group (n=30) without trauma experience. The early adversity group showed altered hypothalamus-pituitary-adrenal axis responses to stress, evidenced by lower ACTH and cortisol responses. Analyses of gene expression patterns showed that stress-responsive transcripts were enriched for genes involved in cytokine activity, cytokine-cytokine receptor interaction, chemokine activity, and G-protein coupled receptor binding. Differences between groups in stress-induced regulation of gene transcription were observed for genes involved in steroid binding, hormone activity, and G-protein coupled receptor binding. Transcription factor binding motif analysis showed an increased activity of pro-inflammatory upstream signaling in the early adversity group. We also identified transcripts that were differentially correlated with stress-induced cortisol increases between the groups, enriched for genes involved in cytokine-cytokine receptor interaction and glutamate receptor signaling. We suggest that childhood adversity leads to persistent alterations in transcriptional control of stress-responsive pathways, which-when chronically or repeatedly activated-might predispose individuals to stress-related psychopathology.

Ancient genes establish stress-induced mutation as a hallmark of cancer.

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Cisneros, Luis; Bussey, Kimberly J; Orr, Adam J; Miočević, Milica; Lineweaver, Charles H; Davies, Paul

2017-01-01

Cancer is sometimes depicted as a reversion to single cell behavior in cells adapted to live in a multicellular assembly. If this is the case, one would expect that mutation in cancer disrupts functional mechanisms that suppress cell-level traits detrimental to multicellularity. Such mechanisms should have evolved with or after the emergence of multicellularity. This leads to two related, but distinct hypotheses: 1) Somatic mutations in cancer will occur in genes that are younger than the emergence of multicellularity (1000 million years [MY]); and 2) genes that are frequently mutated in cancer and whose mutations are functionally important for the emergence of the cancer phenotype evolved within the past 1000 million years, and thus would exhibit an age distribution that is skewed to younger genes. In order to investigate these hypotheses we estimated the evolutionary ages of all human genes and then studied the probability of mutation and their biological function in relation to their age and genomic location for both normal germline and cancer contexts. We observed that under a model of uniform random mutation across the genome, controlled for gene size, genes less than 500 MY were more frequently mutated in both cases. Paradoxically, causal genes, defined in the COSMIC Cancer Gene Census, were depleted in this age group. When we used functional enrichment analysis to explain this unexpected result we discovered that COSMIC genes with recessive disease phenotypes were enriched for DNA repair and cell cycle control. The non-mutated genes in these pathways are orthologous to those underlying stress-induced mutation in bacteria, which results in the clustering of single nucleotide variations. COSMIC genes were less common in regions where the probability of observing mutational clusters is high, although they are approximately 2-fold more likely to harbor mutational clusters compared to other human genes. Our results suggest this ancient mutational response to

Transcriptome Profiling of Louisiana iris Root and Identification of Genes Involved in Lead-Stress Response

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Songqing Tian

2015-11-01

Full Text Available Louisiana iris is tolerant to and accumulates the heavy metal lead (Pb. However, there is limited knowledge of the molecular mechanisms behind this feature. We describe the transcriptome of Louisiana iris using Illumina sequencing technology. The root transcriptome of Louisiana iris under control and Pb-stress conditions was sequenced. Overall, 525,498 transcripts representing 313,958 unigenes were assembled using the clean raw reads. Among them, 43,015 unigenes were annotated and their functions classified using the euKaryotic Orthologous Groups (KOG database. They were divided into 25 molecular families. In the Gene Ontology (GO database, 50,174 unigenes were categorized into three GO trees (molecular function, cellular component and biological process. After analysis of differentially expressed genes, some Pb-stress-related genes were selected, including biosynthesis genes of chelating compounds, metal transporters, transcription factors and antioxidant-related genes. This study not only lays a foundation for further studies on differential genes under Pb stress, but also facilitates the molecular breeding of Louisiana iris.

Functional analysis of atfA gene to stress response in pathogenic thermal dimorphic fungus Penicillium marneffei.

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Panjaphorn Nimmanee

Full Text Available Penicillium marneffei, the pathogenic thermal dimorphic fungus is a causative agent of a fatal systemic disease, penicilliosis marneffei, in immunocompromised patients especially HIV patients. For growth and survival, this fungus has to adapt to environmental stresses outside and inside host cells and this adaptation requires stress signaling pathways and regulation of gene expression under various kinds of stresses. In this report, P. marneffei activating transcription factor (atfA gene encoding bZip-type transcription factor was characterized. To determine functions of this gene, atfA isogenic mutant strain was constructed using the modified split marker recombination method. The phenotypes and susceptibility to varieties of stresses including osmotic, oxidative, heat, UV, cell wall and cell membrane stresses of the mutant strain were compared with the wild type and the atfA complemented strains. Results demonstrated that the mRNA expression level of P. marneffei atfA gene increased under heat stress at 42°C. The atfA mutant was more sensitive to sodium dodecyl sulphate, amphotericin B and tert-butyl hydroperoxide than the wild type and complemented strains but not hydrogen peroxide, menadione, NaCl, sorbitol, calcofluor white, itraconazole, UV stresses and heat stress at 39°C. In addition, recovery of atfA mutant conidia after mouse and human macrophage infections was significantly decreased compared to those of wild type and complemented strains. These results indicated that the atfA gene was required by P. marneffei under specific stress conditions and might be necessary for fighting against host immune cells during the initiation of infection.

Effects of chronic restraint stress on body weight, food intake, and hypothalamic gene expressions in mice.

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Jeong, Joo Yeon; Lee, Dong Hoon; Kang, Sang Soo

2013-12-01

Stress affects body weight and food intake, but the underlying mechanisms are not well understood. We evaluated the changes in body weight and food intake of ICR male mice subjected to daily 2 hours restraint stress for 15 days. Hypothalamic gene expression profiling was analyzed by cDNA microarray. Daily body weight and food intake measurements revealed that both parameters decreased rapidly after initiating daily restraint stress. Body weights of stressed mice then remained significantly lower than the control body weights, even though food intake slowly recovered to 90% of the control intake at the end of the experiment. cDNA microarray analysis revealed that chronic restraint stress affects the expression of hypothalamic genes possibly related to body weight control. Since decreases of daily food intake and body weight were remarkable in days 1 to 4 of restraint, we examined the expression of food intake-related genes in the hypothalamus. During these periods, the expressions of ghrelin and pro-opiomelanocortin mRNA were significantly changed in mice undergoing restraint stress. Moreover, daily serum corticosterone levels gradually increased, while leptin levels significantly decreased. The present study demonstrates that restraint stress affects body weight and food intake by initially modifying canonical food intake-related genes and then later modifying other genes involved in energy metabolism. These genetic changes appear to be mediated, at least in part, by corticosterone.

Effect of ovary induction on bread wheat anther culture: ovary genotype and developmental stage, and candidate gene association.

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Ana María Castillo

2015-06-01

Full Text Available Ovary pre-conditioned medium and ovary co-culture increased the efficiency of green doubled haploid plant production in bread wheat anther culture. The positive effect of this medium led to a 6- and 11-fold increase in the numbers of embryos and green plants, respectively, having a greater effect on a medium-low responding cultivar. Ovary genotype and developmental stage significantly affected microspore embryogenesis. By he use of Caramba ovaries it was possible to reach a 2-fold increase in the number of embryos and green plants, and to decrease the rate of albinism. Mature ovaries from flowers containing microspores at a late binucleate stage raised the number of embryos and green plants by 25% and 46% as compared to immature ovaries (excised from flowers with microspores at a mid-late uninucleate stage. The highest numbers of embryos and green plants were produced when using mature Caramba ovaries. Ovaries from Galeón, Tigre and Kilopondio cultivars successfully induced microspore embryogenesis at the same rate as Caramba ovaries. Moreover, Tigre ovaries raised the percentage of spontaneous chromosome doubling up to 71%. Attempts were made to identify molecular mechanisms associated to the inductive effect of the ovaries on microspore embryogenesis. The genes TAA1b, FLA26 and WALI6 associated to wheat microspore embryogenesis, the CGL1 gene involved in glycan biosynthesis or degradation, and the FER gene involved in the ovary signalling process were expressed and/or induced at different rates during ovary culture. The expression pattern of FLA26 and FER could be related to the differences between genotypes and developmental stages in the inductive effect of the ovary. Our results open opportunities for new approaches to increase bread wheat doubled haploid production by anther culture, and to identify the functional components of the ovary inductive effect on microspore embryogenesis.

Over-expression of a novel JAZ family gene from Glycine soja, increases salt and alkali stress tolerance

International Nuclear Information System (INIS)

Zhu, Dan; Cai, Hua; Luo, Xiao; Bai, Xi; Deyholos, Michael K.; Chen, Qin; Chen, Chao; Ji, Wei; Zhu, Yanming

2012-01-01

Highlights: ► We isolated and characterized a novel JAZ family gene, GsJAZ2, from Glycine soja. ► Overexpression of GsJAZ2 enhanced plant tolerance to salt and alkali stress. ► The transcriptions of stress marker genes were higher in GsJAZ2 overexpression lines. ► GsJAZ2 was localized to nucleus. -- Abstract: Salt and alkali stress are two of the main environmental factors limiting crop production. Recent discoveries show that the JAZ family encodes plant-specific genes involved in jasmonate signaling. However, there is only limited information about this gene family in abiotic stress response, and in wild soybean (Glycine soja), which is a species noted for its tolerance to alkali and salinity. Here, we isolated and characterized a novel JAZ family gene, GsJAZ2, from G. soja. Transcript abundance of GsJAZ2 increased following exposure to salt, alkali, cold and drought. Over-expression of GsJAZ2 in Arabidopsis resulted in enhanced plant tolerance to salt and alkali stress. The expression levels of some alkali stress response and stress-inducible marker genes were significantly higher in the GsJAZ2 overexpression lines as compared to wild-type plants. Subcellular localization studies using a GFP fusion protein showed that GsJAZ2 was localized to the nucleus. These results suggest that the newly isolated wild soybean GsJAZ2 is a positive regulator of plant salt and alkali stress tolerance.

Suitable Reference Genes for Accurate Gene Expression Analysis in Parsley (Petroselinum crispum) for Abiotic Stresses and Hormone Stimuli.

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Li, Meng-Yao; Song, Xiong; Wang, Feng; Xiong, Ai-Sheng

2016-01-01

Parsley, one of the most important vegetables in the Apiaceae family, is widely used in the food, medicinal, and cosmetic industries. Recent studies on parsley mainly focus on its chemical composition, and further research involving the analysis of the plant's gene functions and expressions is required. qPCR is a powerful method for detecting very low quantities of target transcript levels and is widely used to study gene expression. To ensure the accuracy of results, a suitable reference gene is necessary for expression normalization. In this study, four software, namely geNorm, NormFinder, BestKeeper, and RefFinder were used to evaluate the expression stabilities of eight candidate reference genes of parsley ( GAPDH, ACTIN, eIF-4 α, SAND, UBC, TIP41, EF-1 α, and TUB ) under various conditions, including abiotic stresses (heat, cold, salt, and drought) and hormone stimuli treatments (GA, SA, MeJA, and ABA). Results showed that EF-1 α and TUB were the most stable genes for abiotic stresses, whereas EF-1 α, GAPDH , and TUB were the top three choices for hormone stimuli treatments. Moreover, EF-1 α and TUB were the most stable reference genes among all tested samples, and UBC was the least stable one. Expression analysis of PcDREB1 and PcDREB2 further verified that the selected stable reference genes were suitable for gene expression normalization. This study can guide the selection of suitable reference genes in gene expression in parsley.

Suitable reference genes for accurate gene expression analysis in parsley (Petroselinum crispum for abiotic stresses and hormone stimuli

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Meng-Yao Li

2016-09-01

Full Text Available Parsley is one of the most important vegetable in Apiaceae family and widely used in food industry, medicinal and cosmetic. The recent studies in parsley are mainly focus on chemical composition, further research involving the analysis of the gene functions and expressions will be required. qPCR is a powerful method for detecting very low quantities of target transcript levels and widely used for gene expression studies. To ensure the accuracy of results, a suitable reference gene is necessary for expression normalization. In this study, three software geNorm, NormFinder, and BestKeeper were used to evaluate the expression stabilities of eight candidate reference genes (GAPDH, ACTIN, eIF-4α, SAND, UBC, TIP41, EF-1α, and TUB under various conditions including abiotic stresses (heat, cold, salt, and drought and hormone stimuli treatments (GA, SA, MeJA, and ABA. The results showed that EF-1α and TUB were identified as the most stable genes for abiotic stresses, while EF-1α, GAPDH, and TUB were the top three choices for hormone stimuli treatments. Moreover, EF-1α and TUB were the most stable reference genes across all the tested samples, while UBC was the least stable one. The expression analysis of PcDREB1 and PcDREB2 further verified that the selected stable reference genes were suitable for gene expression normalization. This study provides a guideline for selection the suitable reference genes in gene expression in parsley.

Mechanical stress activates Smad pathway through PKCδ to enhance interleukin-11 gene transcription in osteoblasts.

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Shinsuke Kido

Full Text Available BACKGROUND: Mechanical stress rapidly induces ΔFosB expression in osteoblasts, which binds to interleukin (IL-11 gene promoter to enhance IL-11 expression, and IL-11 enhances osteoblast differentiation. Because bone morphogenetic proteins (BMPs also stimulate IL-11 expression in osteoblasts, there is a possibility that BMP-Smad signaling is involved in the enhancement of osteoblast differentiation by mechanical stress. The present study was undertaken to clarify whether mechanical stress affects BMP-Smad signaling, and if so, to elucidate the role of Smad signaling in mechanical stress-induced enhancement of IL-11 gene transcription. METHODOLOGY/PRINCIPAL FINDINGS: Mechanical loading by fluid shear stress (FSS induced phosphorylation of BMP-specific receptor-regulated Smads (BR-Smads, Smad1/5, in murine primary osteoblasts (mPOBs. FSS rapidly phosphorylated Y311 of protein kinase C (PKCδ, and phosphorylated PKCδ interacted with BR-Smads to phosphorylate BR-Smads. Transfection of PKCδ siRNA or Y311F mutant PKCδ abrogated BR-Smads phosphorylation and suppressed IL-11 gene transcription enhanced by FSS. Activated BR-Smads bound to the Smad-binding element (SBE of IL-11 gene promoter and formed complex with ΔFosB/JunD heterodimer via binding to the C-terminal region of JunD. Site-directed mutagenesis in the SBE and the AP-1 site revealed that both SBE and AP-1 sites were required for full activation of IL-11 gene promoter by FSS. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that PKCδ-BR-Smads pathway plays an important role in the intracellular signaling in response to mechanical stress, and that a cross-talk between PKCδ-BR-Smads and ΔFosB/JunD pathways synergistically stimulates IL-11 gene transcription in response to mechanical stress.

Distinct actions of ancestral vinclozolin and juvenile stress on neural gene expression in the male rat

Directory of Open Access Journals (Sweden)

Ross eGillette

2015-03-01

Full Text Available Exposure to the endocrine disrupting chemical vinclozolin during gestation of an F0 generation and/or chronic restraint stress during adolescence of the F3 descendants affects behavior, physiology, and gene expression in the brain. Genes related to the networks of growth factors, signaling peptides and receptors, steroid hormone receptors and enzymes, and epigenetic related factors were measured using quantitative polymerase chain reaction via Taqman low density arrays targeting 48 genes in the central amygdaloid nucleus, medial amygdaloid nucleus, medial preoptic area, lateral hypothalamus, and the ventromedial nucleus of the hypothalamus. We found that growth factors are particularly vulnerable to ancestral exposure in the central and medial amygdala; restraint stress during adolescence affected neural growth factors in the medial amygdala. Signaling peptides were affected by both ancestral exposure and stress during adolescence primarily in hypothalamic nuclei. Steroid hormone receptors and enzymes were strongly affected by restraint stress in the medial preoptic area. Epigenetic related genes were affected by stress in the ventromedial hypothalamus and by both ancestral exposure and stress during adolescence independently in the central amygdala. It is noteworthy that the lateral hypothalamus showed no effects of either manipulation. Gene expression is discussed in the context of behavioral and physiological measures previously published.

Distinct actions of ancestral vinclozolin and juvenile stress on neural gene expression in the male rat.

Science.gov (United States)

Gillette, Ross; Miller-Crews, Isaac; Skinner, Michael K; Crews, David

2015-01-01

Exposure to the endocrine disrupting chemical vinclozolin during gestation of an F0 generation and/or chronic restraint stress during adolescence of the F3 descendants affects behavior, physiology, and gene expression in the brain. Genes related to the networks of growth factors, signaling peptides, and receptors, steroid hormone receptors and enzymes, and epigenetic related factors were measured using quantitative polymerase chain reaction via Taqman low density arrays targeting 48 genes in the central amygdaloid nucleus, medial amygdaloid nucleus, medial preoptic area (mPOA), lateral hypothalamus (LH), and the ventromedial nucleus of the hypothalamus. We found that growth factors are particularly vulnerable to ancestral exposure in the central and medial amygdala; restraint stress during adolescence affected neural growth factors in the medial amygdala. Signaling peptides were affected by both ancestral exposure and stress during adolescence primarily in hypothalamic nuclei. Steroid hormone receptors and enzymes were strongly affected by restraint stress in the mPOA. Epigenetic related genes were affected by stress in the ventromedial nucleus and by both ancestral exposure and stress during adolescence independently in the central amygdala. It is noteworthy that the LH showed no effects of either manipulation. Gene expression is discussed in the context of behavioral and physiological measures previously published.