scholarly journals Functional Analysis of theTrichoderma harzianum nox1Gene, Encoding an NADPH Oxidase, Relates Production of Reactive Oxygen Species to Specific Biocontrol Activity against Pythium ultimum

2011 ◽  
Vol 77 (9) ◽  
pp. 3009-3016 ◽  
Author(s):  
M. Montero-Barrientos ◽  
R. Hermosa ◽  
R. E. Cardoza ◽  
S. Gutiérrez ◽  
E. Monte
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Pythium Ultimum ◽  
Eukaryotic Cells ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Nadph Oxidases ◽  
Content Type ◽  
Biocontrol Activity

ABSTRACTThe synthesis of reactive oxygen species (ROS) is one of the first events following pathogenic interactions in eukaryotic cells, and NADPH oxidases are involved in the formation of such ROS. Thenox1gene ofTrichoderma harzianumwas cloned, and its role in antagonism against phytopathogens was analyzed innox1-overexpressed transformants. The increased levels ofnox1expression in these transformants were accompanied by an increase in ROS production during their direct confrontation withPythium ultimum. The transformants displayed an increased hydrolytic pattern, as determined by comparing protease, cellulase, and chitinase activities with those for the wild type. In confrontation assays againstP. ultimumthenox1-overexpressed transformants were more effective than the wild type, but not in assays againstBotrytis cinereaorRhizoctonia solani. A transcriptomic analysis using aTrichodermahigh-density oligonucleotide (HDO) microarray also showed that, compared to gene expression for the interaction of wild-typeT. harzianumandP. ultimum, genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of anox1-overexpressed transformant with this pathogen. Our results show thatnox1is involved inT. harzianumROS production and antagonism againstP. ultimum.

scholarly journals Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster

2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Cellular Aging ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Ros Scavenging ◽  
Respiratory Pathway ◽  
Male And Female

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

scholarly journals The Characterization of TA-289, a Novel Antifungal from Fusarium sp.

2021 ◽  
Author(s):  
◽  
Natelle C H Quek
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Cycle ◽  
Cell Death ◽  
Reactive Oxygen ◽  
Chemical Diversity ◽  
Mitochondrial Morphology ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type

<p>Natural products offer vast structural and chemical diversity highly sought after in drug discovery research. Saccharomyces cerevisiae makes an ideal model eukaryotic organism for drug mode-of-action studies owing to ease of growth, sophistication of genetic tools and overall homology to higher eukaryotes. Equisetin and a closely related novel natural product, TA-289, are cytotoxic to fermenting yeast, but seemingly less so when yeast actively respire. Cell cycle analyses by flow cytometry revealed a cell cycle block at S-G2/M phase caused by TA-289; previously described oxidative stress-inducing compounds causing cell cycle delay led to further investigation in the involvement of equisetin and TA-289 in mitochondrial-mediated generation of reactive oxygen species. Chemical genomic profiling involving genome-wide scans of yeast deletion mutant strains for TA-289 sensitivity revealed sensitization of genes involved in the mitochondria, DNA damage repair and oxidative stress responses, consistent with a possible mechanism-of-action at the mitochondrion. Flow cytometric detection of reactive oxygen species (ROS) generation caused by TA-289 suggests that the compound may induce cell death via ROS production. The generation of a mutant strain resistant to TA-289 also displayed resistance to a known oxidant, H2O2, at concentrations that were cytotoxic to wild-type cells. The resistant mutant displayed a higher basal level of ROS production compared to the wild-type parent, indicating that the resistance mutation led to an up-regulation of antioxidant capacity which provides cell survival in the presence of TA-289. Yeast mitochondrial morphology was visualized by confocal light microscopy, where it was observed that cells treated with TA-289 displayed abnormal mitochondria phenotypes, further indicating that the compound is acting primarily at the mitochondrion. Similar effects observed with equisetin treatment suggest that both compounds share the same mechanism, eliciting cell death via ROS production in the mitochondrial respiratory chain.</p>

scholarly journals Proteins Needed to Activate a Transcriptional Response to the Reactive Oxygen Species Singlet Oxygen

mBio ◽  
2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Tae-Wook Nam ◽  
Eva C. Ziegelhoffer ◽  
Rachelle A. S. Lemke ◽  
Timothy J. Donohue
Keyword(s):  
Reactive Oxygen Species ◽  
Stress Response ◽  
Singlet Oxygen ◽  
Rhodobacter Sphaeroides ◽  
Transcriptional Response ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Wild Type ◽  
Content Type ◽  
Σ Factor

ABSTRACT Singlet oxygen (1O2) is a reactive oxygen species generated by energy transfer from one or more excited donors to molecular oxygen. Many biomolecules are prone to oxidation by 1O2, and cells have evolved systems to protect themselves from damage caused by this compound. One way that the photosynthetic bacterium Rhodobacter sphaeroides protects itself from 1O2 is by inducing a transcriptional response controlled by ChrR, an anti-σ factor which releases an alternative sigma factor, σE, in the presence of 1O2. Here we report that induction of σE-dependent gene transcription is decreased in the presence of 1O2 when two conserved genes in the σE regulon are deleted, including one encoding a cyclopropane fatty acid synthase homologue (RSP2144) or one encoding a protein of unknown function (RSP1091). Thus, we conclude that RSP2144 and RSP1091 are each necessary to increase σE activity in the presence of 1O2. In addition, we found that unlike in wild-type cells, where ChrR is rapidly degraded when 1O2 is generated, turnover of this anti-σ factor is slowed when cells lacking RSP2144, RSP1091, or both of these proteins are exposed to 1O2. Further, we demonstrate that the organic hydroperoxide tert-butyl hydroperoxide promotes ChrR turnover in both wild-type cells and mutants lacking RSP2144 or RSP1091, suggesting differences in the ways different types of oxidants increase σE activity. IMPORTANCE Oxygen serves many crucial functions on Earth; it is produced during photosynthesis and needed for other pathways. While oxygen is relatively inert, it can be converted to reactive oxygen species (ROS) that destroy biomolecules, cause disease, or kill cells. When energy is transferred to oxygen, the ROS singlet oxygen is generated. To understand how singlet oxygen impacts cells, we study the stress response to this ROS in Rhodobacter sphaeroides, a bacterium that, like plants, generates this compound as a consequence of photosynthesis. This paper identifies proteins that activate a stress response to singlet oxygen and shows that they act in a specific response to this ROS. The identified proteins are found in many free-living, symbiotic, or pathogenic bacteria that can encounter singlet oxygen in nature. Thus, our findings provide new information about a stress response to a ROS of broad biological, agricultural, and biomedical importance.

Lung endothelial cell proliferation with decreased shear stress is mediated by reactive oxygen species

2006 ◽  
Vol 290 (1) ◽  
pp. C66-C76 ◽  
Author(s):  
Tatyana Milovanova ◽  
Shampa Chatterjee ◽  
Yefim Manevich ◽  
Irina Kotelnikova ◽  
Kris DeBolt ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Proliferation ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Nadph Oxidase ◽  
Reactive Oxygen ◽  
Proliferation Index ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type

Acute cessation of flow (ischemia) leads to depolarization of the endothelial cell (EC) membrane mediated by KATP channels and followed by production of reactive oxygen species (ROS) from NADPH oxidase. We postulated that ROS are a signal for initiating EC proliferation associated with the loss of shear stress. Flow cytometry was used to identify proliferating CD31-positive pulmonary microvascular endothelial cells (mPMVECs) from wild-type, Kir6.2−/−, and gp91 phox−/− mice. mPMVECs were labeled with PKH26 and cultured in artificial capillaries for 72 h at 5 dyn/cm2 (flow adaptation), followed by 24 h of stop flow or continued flow. ROS production during the first hour of ischemia was markedly diminished compared with wild-type mice in both types of gene-targeted mPMVECs. Cell proliferation was defined as the proliferation index (PI). After 72 h of flow, >98% of PKH26-labeled wild-type mPMVECs were at a single peak (PI 1.0) and the proportion of cells in the S+G2/M phases were at 5.8% on the basis of cell cycle analysis. With ischemia (24 h), PI increased to 2.5 and the ratio of cells in S+G2/M phases were at 35%. Catalase, diphenyleneiodonium, and cromakalim markedly inhibited ROS production and cell proliferation in flow-adapted wild-type mPMVECs. Significant effects of ischemia were not observed in Kir6.2−/− and gp91 phox−/− cells. ANG II activation of NADPH oxidase was unaffected by KATP gene deletion. Thus loss of shear stress in flow-adapted mPMVECs results in cell division associated with ROS generated by NADPH oxidase. This effect requires a functioning cell membrane KATP channel.

scholarly journals The Small GTPase RacA Mediates Intracellular Reactive Oxygen Species Production, Polarized Growth, and Virulence in the Human Fungal Pathogen Aspergillus fumigatus

2010 ◽  
Vol 10 (2) ◽  
pp. 174-186 ◽  
Author(s):  
Haiyan Li ◽  
Bridget M. Barker ◽  
Nora Grahl ◽  
Srisombat Puttikamonkul ◽  
Jeremey D. Bell ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Aspergillus Fumigatus ◽  
Invasive Pulmonary Aspergillosis ◽  
Reactive Oxygen ◽  
Small Gtpase ◽  
Oxygen Species ◽  
Wild Type ◽  
Content Type ◽  
Diphenylene Iodonium

ABSTRACTAspergillus fumigatusis the predominant mold pathogen in immunocompromised patients. In this study, we present the first characterization of the small GTPase RacA inA. fumigatus. To gain insight into the function ofracAin the growth and pathogenesis ofA. fumigatus, we constructed a strain that lacks a functionalracAgene. The ΔracAstrain showed significant morphological defects, including a reduced growth rate and abnormal conidiogenesis on glucose minimal medium. In the ΔracAstrain, apical dominance in the leading hyphae is lost and, instead, multiple axes of polarity emerge. Intriguingly, superoxide production at the hyphal tips was reduced by 25% in the ΔracAstrain. Treatment of wild-type hyphae with diphenylene iodonium, an inhibitor of NADPH oxidase, resulted in phenotypes similar to that of the ΔracAstrain. These data suggest that ΔracAstrain phenotypes may be due to a reduction or alteration in the production of reactive oxygen species. Most surprisingly, despite these developmental and growth abnormalities, the ΔracAstrain retained at least wild-type virulence in both an insect model and two immunologically distinct murine models of invasive pulmonary aspergillosis. These results demonstrate thatin vitrogrowth phenotypes do not always correlate within vivovirulence and raise intriguing questions about the role of RacA inAspergillusvirulence.

scholarly journals Induction of Mitochondrial Reactive Oxygen Species Production by Itraconazole, Terbinafine, and Amphotericin B as a Mode of Action against Aspergillus fumigatus

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Elena Shekhova ◽  
Olaf Kniemeyer ◽  
Axel A. Brakhage
Keyword(s):  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Complex I ◽  
Reactive Oxygen ◽  
Antifungal Compounds ◽  
Ros Production ◽  
Oxygen Species ◽  
Content Type

ABSTRACT Drug resistance in fungal pathogens is of incredible importance to global health, yet the mechanisms of drug action remain only loosely defined. Antifungal compounds have been shown to trigger the intracellular accumulation of reactive oxygen species (ROS) in human-pathogenic yeasts, but the source of those ROS remained unknown. In the present study, we examined the role of endogenous ROS for the antifungal activity of the three different antifungal substances itraconazole, terbinafine, and amphotericin B, which all target the fungal cell membrane. All three antifungals had an impact on fungal redox homeostasis by causing increased intracellular ROS production. Interestingly, the elevated ROS levels induced by antifungals were abolished by inhibition of the mitochondrial respiratory complex I with rotenone. Further, evaluation of lipid peroxidation using the thiobarbituric acid assay revealed that rotenone pretreatment decreased ROS-induced lipid peroxidation during incubation of Aspergillus fumigatus with itraconazole and terbinafine. By applying the mitochondrion-specific lipid peroxidation probe MitoPerOx, we also confirmed that ROS are induced in mitochondria and subsequently cause significant oxidation of mitochondrial membrane in the presence of terbinafine and amphotericin B. To summarize, our study suggests that the induction of ROS production contributes to the ability of antifungal compounds to inhibit fungal growth. Moreover, mitochondrial complex I is the main source of deleterious ROS production in A. fumigatus challenged with antifungal compounds.

Arabidopsis thaliana constitutively active ROP11 interacts with the NADPH oxidase respiratory burst oxidase homologue F to regulate reactive oxygen species production in root hairs

2016 ◽  
Vol 43 (3) ◽  
pp. 221 ◽  
Author(s):  
Min Yan ◽  
Wen Jing ◽  
Ni Xu ◽  
Like Shen ◽  
Qun Zhang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Arabidopsis Thaliana ◽  
Respiratory Burst ◽  
Root Hairs ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Respiratory Burst Oxidase ◽  
Constitutively Active

Reactive oxygen species (ROS) play a key signalling role in cells. Plant NADPH oxidases, also known as respiratory burst oxidase homologues (Rbohs), are well characterised ROS-generating systems. In this study, we found that the constitutively active small guanosine triphosphatase (GTPase) ROP11 (CA-ROP11) interacted with RbohF by using a yeast two-hybrid analysis, a pull-down assay and an in vivo bimolecular fluorescence complementation assay. The mutation of amino acid L336 or L337 in RbohF abolished its interaction with CA-ROP11. Coexpression of CA-ROP11 and wild-type RbohF in Nicotiana benthamiana Domin enhanced ROS production compared with coexpression of CA-ROP11 and mutant RbohF or of dominant negative ROP11 and wild-type RbohF. Moreover, CA-ROP11 overexpression resulted in ROS accumulation and a swollen root hair phenotype in Arabidopsis thaliana (L.) Heynh. The deletion of RbohF partially reduced the increase in ROS in Arabidopsis plants overexpressing CA-ROP11. These results suggest that Arabidopsis ROP11 modulates ROS production by interacting with RbohF in root hairs.

Production of Extracellular Reactive Oxygen Species by Marine Biota

2021 ◽  
Vol 13 (1) ◽  
pp. 177-200
Author(s):  
Colleen M. Hansel ◽  
Julia M. Diaz
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Taxonomic Diversity ◽  
Aqueous Environment ◽  
Marine Biota ◽  
Ros Production ◽  
Oxygen Species ◽  
Biological Interactions ◽  
Nadph Oxidases ◽  
Defense Systems

Reactive oxygen species (ROS) are produced ubiquitously across the tree of life. Far from being synonymous with toxicity and harm, biological ROS production is increasingly recognized for its essential functions in signaling, growth, biological interactions, and physiochemical defense systems in a diversity of organisms, spanning microbes to mammals. Part of this shift in thinking can be attributed to the wide phylogenetic distribution of specialized mechanisms for ROS production, such as NADPH oxidases, which decouple intracellular and extracellular ROS pools by directly catalyzing the reduction of oxygen in the surrounding aqueous environment. Furthermore, biological ROS production contributes substantially to natural fluxes of ROS in the ocean, thereby influencing the fate of carbon, metals, oxygen, and climate-relevant gases. Here, we review the taxonomic diversity, mechanisms, and roles of extracellular ROS production in marine bacteria, phytoplankton, seaweeds, and corals, highlighting the ecological and biogeochemical influences of this fundamental and remarkably widespread process.

scholarly journals Mutant Kras as a Biomarker Plays a Favorable Role in FL118-Induced Apoptosis, Reactive Oxygen Species (ROS) Production and Modulation of Survivin, Mcl-1 and XIAP in Human Bladder Cancer

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3413
Author(s):  
Sreevidya Santha ◽  
Xiang Ling ◽  
Ieman A. M. Aljahdali ◽  
Sailee S. Rasam ◽  
Xue Wang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Bladder Cancer ◽  
Reactive Oxygen ◽  
In Vivo Studies ◽  
Parp Cleavage ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Kras Mutations

Tumor heterogeneity in key gene mutations in bladder cancer (BC) is a major hurdle for the development of effective treatments. Using molecular, cellular, proteomics and animal models, we demonstrated that FL118, an innovative small molecule, is highly effective at killing T24 and UMUC3 high-grade BC cells, which have Hras and Kras mutations, respectively. In contrast, HT1376 BC cells with wild-type Ras are insensitive to FL118. This concept was further demonstrated in additional BC and colorectal cancer cells with mutant Kras versus those with wild-type Kras. FL118 strongly induced PARP cleavage (apoptosis hallmark) and inhibited survivin, XIAP and/or Mcl-1 in both T24 and UMUC3 cells, but not in the HT1376 cells. Silencing mutant Kras reduced both FL118-induced PARP cleavage and downregulation of survivin, XIAP and Mcl-1 in UMUC3 cells, suggesting mutant Kras is required for FL118 to exhibit higher anticancer efficacy. FL118 increased reactive oxygen species (ROS) production in T24 and UMUC3 cells, but not in HT1376 cells. Silencing mutant Kras in UMUC3 cells reduced FL118-mediated ROS generation. Proteomics analysis revealed that a profound and opposing Kras-relevant signaling protein is changed in UMUC3 cells and not in HT1376 cells. Consistently, in vivo studies indicated that UMUC3 tumors are highly sensitive to FL118 treatment, while HT1376 tumors are highly resistant to this agent. Silencing mutant Kras in UMUC3 cell-derived tumors decreases UMUC3 tumor sensitivity to FL118 treatment. Together, our studies revealed that mutant Kras is a favorable biomarker for FL118 targeted treatment.

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