scholarly journals Chloroplast-derived photo-oxidative stress causes changes in H2O2 and EGSH in other subcellular compartments

2020 ◽  
Author(s):  
José Manuel Ugalde ◽  
Philippe Fuchs ◽  
Thomas Nietzel ◽  
Edoardo A. Cutolo ◽  
Ute C. Vothknecht ◽  
...  
Keyword(s):  
Electron Transport ◽  
Methyl Viologen ◽  
Nuclear Gene ◽  
Reducing Power ◽  
Photosynthetic Electron Transport ◽  
Ros Generation ◽  
Dependent Manner ◽  
Ros Scavenging ◽  
Actinic Light

ABSTRACTMetabolic fluctuations in chloroplasts and mitochondria can trigger retrograde signals to modify nuclear gene expression. Mobile signals likely to be involved are reactive oxygen species (ROS), which can operate protein redox switches by oxidation of specific cysteine residues. Redox buffers such as the highly reduced glutathione pool serve as reservoirs of reducing power for several ROS scavenging and ROS-induced damage repair pathways. Formation of glutathione disulfide (GSSG) and a shift of the glutathione redox potential (EGSH) towards less negative values is considered a hallmark of several stress conditions. Here we used the herbicide methyl viologen (MV) to generate ROS locally in chloroplasts of intact Arabidopsis seedlings and recorded dynamic changes in EGSH and H2O2 levels with the genetically-encoded biosensors Grx1-roGFP2 (for EGSH) and roGFP2-Orp1 (for H2O2) targeted to chloroplasts, the cytosol or mitochondria. Treatment of seedlings with MV caused a rapid oxidation in chloroplasts and subsequently also in the cytosol and mitochondria. The MV-induced oxidation was significantly boosted by illumination with actinic light and largely abolished by inhibitors of photosynthetic electron transport. In addition, MV also induced an autonomous oxidation in the mitochondrial matrix in an electron transport chain activity-dependent manner that was milder than the oxidation triggered in chloroplasts by the combination of MV and light. In vivo redox biosensing resolves the spatiotemporal dynamics of compartmental responses to local ROS generation and provide a basis for understanding how compartment-specific redox dynamics may operate in retrograde signaling and stress acclimation in plants.One sentence summaryMethyl viologen-induced photooxidative stress causes an increase of H2O2 and oxidation of glutathione in chloroplasts, cytosol and mitochondria as well as autonomous oxidation in mitochondria.

scholarly journals FGF1ΔHBS prevents diabetic cardiomyopathy by maintaining mitochondrial homeostasis and reducing oxidative stress via AMPK/Nur77 suppression

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Dezhong Wang ◽  
Yuan Yin ◽  
Shuyi Wang ◽  
Tianyang Zhao ◽  
Fanghua Gong ◽  
...  
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Metabolic Regulation ◽  
Cardiac Injury ◽  
Serum Levels ◽  
Ros Generation ◽  
Dependent Manner ◽  
Cardiac Tissues ◽  
Beneficial Effects

AbstractAs a classically known mitogen, fibroblast growth factor 1 (FGF1) has been found to exert other pleiotropic functions such as metabolic regulation and myocardial protection. Here, we show that serum levels of FGF1 were decreased and positively correlated with fraction shortening in diabetic cardiomyopathy (DCM) patients, indicating that FGF1 is a potential therapeutic target for DCM. We found that treatment with a FGF1 variant (FGF1∆HBS) with reduced proliferative potency prevented diabetes-induced cardiac injury and remodeling and restored cardiac function. RNA-Seq results obtained from the cardiac tissues of db/db mice showed significant increase in the expression levels of anti-oxidative genes and decrease of Nur77 by FGF1∆HBS treatment. Both in vivo and in vitro studies indicate that FGF1∆HBS exerted these beneficial effects by markedly reducing mitochondrial fragmentation, reactive oxygen species (ROS) generation and cytochrome c leakage and enhancing mitochondrial respiration rate and β-oxidation in a 5’ AMP-activated protein kinase (AMPK)/Nur77-dependent manner, all of which were not observed in the AMPK null mice. The favorable metabolic activity and reduced proliferative properties of FGF1∆HBS testify to its promising potential for use in the treatment of DCM and other metabolic disorders.

The Phycobihproteids in Cyanophora paradoxa as Accessoric Pigments and Nitrogen Storage Proteins

1983 ◽  
Vol 38 (11-12) ◽  
pp. 972-977 ◽  
Author(s):  
Hainfried E. A. Schenk ◽  
Jürgen Hanf ◽  
Margarete Neu-Müller
Keyword(s):  
Electron Transport ◽  
Stress Proteins ◽  
Nitrogen Starvation ◽  
Storage Proteins ◽  
Photosynthetic Electron Transport ◽  
Lower Degree ◽  
Nitrogen Storage ◽  
Cyanophora Paradoxa ◽  
Free Living

The phycobiliproteids of cyanobacteria have two functions. They are accessoric pigments for the light-dependent photosynthetic electron transport, and, secondly, they are storage proteins. Cyanocyta korschikoffiana, the endocyanelle of Cyanophora paradoxa, a hardly adapted endocytobiotic cyanobacterium, is responsible for the photoautotrophy of the host flagellate. The biosynthesis of the phycobiliproteids takes place in the endocyanelles and is reversible. Under nitrogen starvation the phycobiliproteids were disintegrated again, in contrast to the carotenoids (and in a lower degree to chlorophyll), whose contents rem ain more constant in the cells, as shown by in vivo measurements. Therefore, it is concluded that sim ilar to the function in free living cyanobacteria the phycobiliproteids of C. paradoxa also serve as storage substances (“stress proteins”). This opinion is supported by experiments with chloramphenicol

Metribuzin-Resistant Mutants of Chlamydomonas reinhardii

1984 ◽  
Vol 39 (5) ◽  
pp. 437-439 ◽  
Author(s):  
N. Pucheu ◽  
W. Oettmeier ◽  
U. Heisterkamp ◽  
K. Masson ◽  
G.F. Wildner
Keyword(s):  
Electron Transport ◽  
Photosynthetic Electron Transport ◽  
Wild Type ◽  
Binding Studies ◽  
Molecular Weight Range ◽  
Chlamydomonas Reinhardii ◽  
Thylakoid Membrane Proteins ◽  
Mutant Strains ◽  
Resistant Mutants

Herbicide resistance in Chlamydomonas reinhardii cells was induced by mutagenesis with 5-fluorodeoxyuridine and ethylmethanesulfonate. Four mutant strains were isolated and analyzed for resistance against DCMU-type or phenolic inhibitors of photosynthetic electron transport. The mutants were different in both the extent and the pattern of their resistance: the R/S value, i.e. the ratio of I50 values of the inhibition of photosynthetic electron transport in isolated resistant and susceptible thylakoids, varied for metribuzin from 10 000 to 36. The mutant MZ-1 was resistant against metribuzin, atrazine and DCMU, whereas the mutant MZ-2 showed resistance mainly against metribuzin and atrazine. The mutant MZ-3 was similar to MZ-1, but showed a lesser extent of resistance against DCMU. The mutant MZ-4 showed resistance against metribuzin, but not against atrazine. These results demonstrate that the resistance against one herbicide of the DCMU-type (metribuzin) must not be accompanied by similar resistance against te other inhibitors. Binding studies with radioactively labeled herbicides, [14C]metribuzin, [14C]atrazine and [3H]DCMU, and isolated thylakoids supported these observations. Phosphorylation of thylakoid membrane proteins was studied with wild-type cells and resistant mutants under in vivo conditions in the light. The 32P-labeled main proteins bands were in the molecular weight range of 10-14 kDa, 26-29 kDa, 32-35 kDa and 46-48 kDa. The pattern and the extent of incorporation of 32P were similar for the mutants and the wild-type cells.

scholarly journals Capilliposide Isolated fromLysimachia capillipesHemsl. Induces ROS Generation, Cell Cycle Arrest, and Apoptosis in Human Nonsmall Cell Lung Cancer Cell Lines

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Zheng-hua Fei ◽  
Kan Wu ◽  
Yun-liang Chen ◽  
Bing Wang ◽  
Shi-rong Zhang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Nonsmall Cell Lung Cancer ◽  
Control Group ◽  
Ros Generation ◽  
Dependent Manner ◽  
Apoptotic Pathway ◽  
Cycle Arrest

Several data has reported that capilliposide, extracted from a traditional Chinese medicine,Lysimachia capillipesHemsl. (LC) could exhibit inhibitory effect on cell proliferation in various cancers. The current study investigated the antitumor efficacy ofCapilliposideand elucidated its potential molecular mechanism involved in vivo and vitro. Our results indicated that LC capilliposide inhibited proliferation of lung cancer cells in a dose-dependent manner. LC capilliposide induced cell cycle arrest at the S stage and enhanced apoptosis in NSCLC cells. Treatment with LC capilliposide increased the intracellular level of ROS, which activated the mitochondrial apoptotic pathway. Blockage of ROS by NAC highly reversed the effect of LC capilliposide on apoptosis. Xenograft tumor growth was significantly lower in the LC-treated group compared with the untreated control group(P<0.05). The results also show that LC treatment does not produce any overt signs of acute toxicity in vivo. These findings demonstrate that LC capilliposide could exert an anti-tumor effect on NSCLC through mitochondrial-mediated apoptotic pathway and the activation of ROS is involved.

On the Mechanism of Benzoquinone Penetration and Photoreduction by Whole Cells

1971 ◽  
Vol 26 (6) ◽  
pp. 585-588 ◽  
Author(s):  
H. Gimmler ◽  
M. Avron
Keyword(s):  
Electron Transport ◽  
Cell Membrane ◽  
Photosynthetic Electron Transport ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Porphyridium Cruentum ◽  
Whole Cells ◽  
Time Treatment ◽  
Short Time

Short time treatment of intact Porphyridium cruentum cells with benzoquinone results in changes of the cell membranes, which lead to a higher permeability. This increased permeability allows the measurements of photosynthetic electron transport reactions with various electron donors, ac. ceptors and mediators, which cannot enter untreated cells. The capacity of benzoquinone to act as a Hill - reagent in vivo is interpreted as due to a double action of this compound: changing the permeability of the cells by reacting with the cell membrane coupled with the ability of the unreacted molecules to serve as electron acceptors.

scholarly journals IN VITRO ANTIOXIDANT AND IN VIVO ANTI-INFLAMMATORY ACTIVITY OF THE AERIAL PART OF BLUMEA ERIANTHA DC

2018 ◽  
Vol 10 (7) ◽  
pp. 75 ◽  
Author(s):  
Urmila U. Tambewagh ◽  
Supada Rambhau Rojatkar
Keyword(s):  
Antioxidant Activity ◽  
Aerial Part ◽  
Methanol Extract ◽  
Reducing Power ◽  
Dependent Manner ◽  
Paw Edema ◽  
Anti Inflammatory ◽  
In Vitro Antioxidant Activity

Objective: Objective of the present study was to carry out in vivo anti-inflammatory and in vitro antioxidant activity of methanol extract of aerial part of the Blumea eriantha DC belonging to family Asteraceae.Methods: The shade dried aerial part of B. eriantha (0.5 kg) was powdered and extracted with methanol (1.5 x 3L) at room temperature (24h x 3). After filtration combined all the three extracts and were concentrated on rotary evaporator under reduced pressure at 40 °C, thereby providing crude methanol extract which was subsequently employed for further studies. Anti-inflammatory effect was studied by carrageenan-induced paw edema model in rats at dose level 100, 200, and 400 mg/kg. Acute oral toxicity study and in vitro antioxidant potential of the extract was also studied. The in vitro antioxidant activity of methanol extract of aerial part of Blumea eriantha DC was evaluated against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) and hydroxyl (OH) radicalscavenging and reducing power assays.Results: The results indicate that methanol extract of Blumea eriantha (BEME, 400 mg/kg) exhibited significant inhibition (p<0.001) of increase in paw edema at 5th h. IC50 value of BEME showed significant antioxidant activity. The extract exhibits promising free radical scavenging effect of DPPH, H2O2, OH and reducing power in a dose-dependent manner up to 100µg/ml concentration while the reference standard Ascorbic acid demonstrated more scavenging potential than the methanol extract of Blumea eriantha The methanol extract was found to be safe at the dose of 2000 mg/kg.Conclusion: The results of the experimental study confirmed that methanol extract of Blumea eriantha DC possesses significant anti-inflammatory and antioxidant activity.

Lymphocytic microparticles inhibit angiogenesis by stimulating oxidative stress and negatively regulating VEGF-induced pathways

2008 ◽  
Vol 294 (2) ◽  
pp. R467-R476 ◽  
Author(s):  
Chun Yang ◽  
Bupe R. Mwaikambo ◽  
Tang Zhu ◽  
Carmen Gagnon ◽  
Josiane Lafleur ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Function ◽  
Umbilical Vein ◽  
Ros Generation ◽  
Vegf Receptor ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Endothelial Cell Function

Recent studies have demonstrated that lymphocyte-derived microparticles (LMPs) impair endothelial cell function. However, no data currently exist regarding the contribution of LMPs in the regulation of angiogenesis. In the present study, we investigated the effects of LMPs on angiogenesis in vivo and in vitro and demonstrated that LMPs strongly suppressed aortic ring microvessel sprouting and in vivo corneal neovascularization. In vitro, LMPs considerably diminished human umbilical vein endothelial cell survival and proliferation in a concentration-dependent manner. Mechanistically, the antioxidants U-74389G and U-83836E were partially protective against the antiproliferative effects of LMPs, whereas the NADPH oxidase (NOX) inhibitors apocynin and diphenyleneiodonium significantly abrogated these effects. Moreover, LMPs increased not only the expression of the NOX subunits gp91phox, p22phox, and p47phox, but also the production of ROS and NOX-derived superoxide (O2−). Importantly, LMPs caused a pronounced augmentation in the protein expression of the CD36 antiangiogenic receptor while significantly downregulating the protein levels of VEGF receptor type 2 and its downstream signaling mediator, phosphorylated ERK1/2. In summary, LMPs potently suppress neovascularization in vivo and in vitro by augmenting ROS generation via NOX and interfering with the VEGF signaling pathway.

Multiple in vivo Effects of Cadmium on Photosynthetic Electron Transport in Pea Plants

2021 ◽  
Author(s):  
Daria Todorenko ◽  
Alena Volgusheva ◽  
Nyurgun Timofeev ◽  
Ilya Kovalenko ◽  
Dmitry Matorin ◽  
...  
Keyword(s):  
Electron Transport ◽  
Photosynthetic Electron Transport ◽  
In Vivo Effects

scholarly journals RIPK3 Contributes to Lyso-Gb3-Induced Podocyte Death

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 245
Author(s):  
So-Young Kim ◽  
Samel Park ◽  
Seong-Woo Lee ◽  
Ji-Hye Lee ◽  
Eun Soo Lee ◽  
...  
Keyword(s):  
Fabry Disease ◽  
Kidney Injury ◽  
Ros Generation ◽  
Dependent Manner ◽  
Lysosomal Storage ◽  
Cellular Mechanisms ◽  
Cell Death Pathways ◽  
Fabry Nephropathy

Fabry disease is a lysosomal storage disease with an X-linked heritage caused by absent or decreased activity of lysosomal enzymes named alpha-galactosidase A (α-gal A). Among the various manifestations of Fabry disease, Fabry nephropathy significantly affects patients’ morbidity and mortality. The cellular mechanisms of kidney damage have not been elusively described. Necroptosis is one of the programmed necrotic cell death pathways and is known to play many important roles in kidney injury. We investigated whether RIPK3, a protein phosphokinase with an important role in necroptosis, played a crucial role in the pathogenesis of Fabry nephropathy both in vitro and in vivo. The cell viability of podocytes decreased after lyso-Gb3 treatment in a dose-dependent manner, with increasing RIPK3 expression. Increased reactive oxygen species (ROS) generation after lyso-Gb3 treatment, which was alleviated by GSK’872 (a RIPK3 inhibitor), suggested a role of oxidative stress via a RIPK3-dependent pathway. Cytoskeleton rearrangement induced by lyso-Gb3 was normalized by the RIPK3 inhibitor. When mice were injected with lyso-Gb3, increased urine albuminuria, decreased podocyte counts in the glomeruli, and effaced foot processes were observed. Our results showed that lyso-Gb3 initiated albuminuria, a clinical manifestation of Fabry nephropathy, by podocyte loss and subsequent foot process effacement. These findings suggest a novel pathway in Fabry nephropathy.

Studies on 18O2-Uptake in the Light by Entire Plants of Different Tobacco Mutants

1982 ◽  
Vol 37 (1-2) ◽  
pp. 93-101 ◽  
Author(s):  
Ryuichi Ishii ◽  
Georg H. Schmid
Keyword(s):  
Electron Transport ◽  
Reducing Power ◽  
Photosynthetic Electron Transport ◽  
The Other ◽  
Deficient Mutant ◽  
Type Reaction ◽  
Transport Chain ◽  
Glycolate Metabolism ◽  
Assay Conditions ◽  
The Warburg Effect

Photorespiratory activity was measured in entire plants of five tobacco variants. These tobacco variants are: the green type N. tabacum var. John William’s Broadleaf (su/su Aur/aur or su/su Aur/Aur) the chlorophyll-deficient tobacco mutant Su/su (Su/su Aur/Aur) and the chlorophyll- deficient mutant Su/su var. Aurea (Su/su Aur/aur). Furthermore, two recently characterized phenotypes originating from N. tabacum var. Consolation namely “consolation green” (Aa Bb) and “consolation yellow-green” (aa bb). In entire plants of these phenotypes photorespiration was measured as 18O2-uptake in the light. This uptake was compared with the enhancement of CO2- fixation in the Warburg effect i. e. when the oxygen partial pressure is lowered from 21% Oz to 3% O2. The principal conclusion from these measurements is firstly that under the assay conditions which are identical for all 5 phenotypes (330 ppm CO2, 14000 lux white light and 25 °C) all five phenotypes yield considerable differences in photorespiratory activity. Furthermore, we were able to show that in the different phenotypes the global O2-uptake in the light is repartitioned to different degrees among different metabolic pathways. Thus, in JWB which is under the assay conditions the only fast growing species, only half of the measured 18O2-uptake belongs to glycolate metabolism or photorespiration proper, the other half belongs to a Mehler type reaction in which excess reducing power is eliminated apparently already at the level of photosynthetic electron transport. In the chlorophyll-deficient mutant Su/su, however, the observed 18O2-uptake in the light belongs under the assay conditions exclusively to glycolate metabolism (no Mehler type reaction). The chlorophyll-deficient mutant Su/su var. Aurea behaves more like JWB, that is, part of its 18O2-uptake is due to a Mehler type reaction and only the remainder is involved in CO2- metabolism, which has been already found out previously by genetic analysis. In addition photorespiration depends in Su/su more on the temperature than in the other phenotypes tested. One of the implications of our results could be that it makes a difference to the plant whether excess reducing power is disposed of at the level of the photosynthetic electron transport chain (via a Mehler type reaction) or at the level of CO2-metabolism.

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