Living in a hot redox soup: antioxidant defences of the hydrothermal worm Alvinella pompejana

B Genard; B Marie; E Loumaye; B Knoops; P Legendre; F Zal; JF Rees

doi:10.3354/ab00498

Meeting the Salinity Requirements of the Bivalve Mollusc Crassostrea gigas in the Depuration Process and Posterior Shelf-Life Period to Improve Food Safety and Product Quality

Water ◽

10.3390/w13081126 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1126

Author(s):

João A. Silvestre ◽

Sílvia F. S. Pires ◽

Vitória Pereira ◽

Miguel Colaço ◽

Ana P. L. Costa ◽

...

Keyword(s):

Food Safety ◽

Shelf Life ◽

Crassostrea Gigas ◽

Storage Period ◽

Microbiological Contamination ◽

Bivalve Molluscs ◽

Antioxidant Defences ◽

Life Period ◽

Microbiological Analyses ◽

Depuration Process

Microbiological contamination of bivalve molluscs is one of the major concerns inherent to food safety, thus depuration is frequently needed to assure food safety levels associated with their consumption. Salinity plays an important role in the metabolic activity of bivalves and as such can influence their depuration capacity. This study aimed to evaluate the effect of salinity (25, 30, 35 and 40) on the efficiency of the depuration process, along with the quality and shelf-life of Crassostrea gigas. For this, a 24-h depuration was carried out, followed by a storage period at 5 ± 1 °C for six days. Microbiological analyses and biochemical parameters related to oxidative stress response were analysed. Escherichia coli load was reduced in only 24 h, disregarding the salinity of the system. After the shelf-life period, the activity of the antioxidant defences at salinities 35 and 40 is higher but is still not sufficient to avoid lipid peroxidation. Over time, there is a decrease in oyster metabolism probably due to being chilled and to the action of exposure to air. In sum, this study suggests salinities between 25 and 30 as preferential for the depuration process of C. gigas and subsequent quality during shelf-life.

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Parenteral Nutrition and Oxidant Load in Neonates

Nutrients ◽

10.3390/nu13082631 ◽

2021 ◽

Vol 13 (8) ◽

pp. 2631

Author(s):

Kandeepan Karthigesu ◽

Robert F. Bertolo ◽

Robert J. Brown

Keyword(s):

Parenteral Nutrition ◽

Storage Temperature ◽

Oral Feeding ◽

Published Data ◽

Short Term ◽

Antioxidant Defences ◽

Term Survival ◽

Nutrient Sources ◽

Short Term Survival

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

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Antioxidant enzymes in sea cucumber Apostichopus japonicus (Selenka) during aestivation

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315410000779 ◽

2010 ◽

Vol 91 (1) ◽

pp. 209-214 ◽

Cited By ~ 9

Author(s):

Wang Fangyu ◽

Yang Hongsheng Yang ◽

Wang Xiaoyu ◽

Xing Kun ◽

Gao Fei

Keyword(s):

Oxygen Consumption ◽

Glutathione Peroxidase ◽

Sea Cucumber ◽

Apostichopus Japonicus ◽

Sampling Period ◽

Coelomic Fluid ◽

Sharp Change ◽

Antioxidant Defence ◽

Antioxidant Defences ◽

And Function

To evaluate the effect of antioxidant defence in coelomic fluid of sea cucumber, Apostichopus japonicus in aestivation was studied in the field from July to November 2006 in Qingdao. During the sampling period, activities of superoxide dismutase and catalase increased significantly in August and November. Activities of glutathione reductase and glutathione decreased significantly in August and increased significantly in November and activities of Se-glutathione peroxidase increased significantly in August. There were no significant differences in total glutathione peroxidase. In relation to the water temperature in the field, it is known that the oxygen consumption rate dropped and antioxidant defence was enhanced in August. The structure and function of respiratory trees of A. japonicus were completely vivified as normal in November, and it is suggested that antioxidant defence was enhanced because of the sharp change of oxygen consumption. Data indicate that both enzymatic and metabolite antioxidant defences in sea cucumber are adaptable systems that are modulated during pre-aestivating stage and arousing stage.

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The cellular and flagella morphologies of ulcerogenic Helicobacter pylori paediatric strains.

Microscopy and Microanalysis ◽

10.1017/s143192761300072x ◽

2013 ◽

Vol 19 (S4) ◽

pp. 21-22

Author(s):

I. Vitoriano ◽

K.D. Saraiva-Pava ◽

A.P.A. Matos ◽

F.F. Vale ◽

A. Santos ◽

...

Keyword(s):

Helicobacter Pylori ◽

Optical Microscopy ◽

Young Patients ◽

Rare Event ◽

Uranyl Acetate ◽

Bacterial Suspension ◽

Antioxidant Defences ◽

Tem Analysis ◽

Thin Sections ◽

H Pylori

Helicobacter pylori is a pathogenic spiral-shaped, microaerophilic, gram-negative bacterium, that inhabits the human stomach. Infection is usually acquired during childhood and always elicits an acute immune response that is, however, inefficient in bacteria clearance. Therefore, in the absence of effective treatment, infection and gastritis (non ulcer dyspepsia, NUD) persist throughout the patient’s life. Depending on its severity and pattern, in about 15% of infected adults, this silent destruction of the gastric mucosa may further progress to peptic ulcer disease (PUD) (gastric and duodenal ulcers, GU and DU respectively) and/or gastric cancer. Infection with H. pylori is also the major cause for the development of paediatric PUD, a rare event that may occur shortly after infection. In addition to the still undisclosed genetic susceptibility of these young patients, the virulence of the implicated H. pylori strain plays a crucial role in the paediatric PUD pathogenesis. Recently, we proved by in vitro infection assays that, compared with paediatric NUD-associated isolates, a group of paediatric ulcerogenic-strains present a greater ability to induce a marked decrease in the gastric cells viability and to cause them severe cytoskeleton damage and mucins’ production/secretion impairment. Moreover, we showed that their enhanced virulence result from a synergy between the ability to better adapt to the hostility of their niche and the expression of cagA, vacAs1, oipA ‘‘on’’ status, homB and jhp562 virulence factors. Accordingly, these ulcerogenic strains share a particular proteome profile, providing them with better antioxidant defences, a metabolism favouring the biosynthesis of aromatic amino acids and higher motility.We are now characterizing/comparing the cellular and flagella morphologies of H. pylori strains isolated from Portuguese children, associated with DU, GU or NUD, belonging to the vast and multiethnic collection of the Instituto Nacional de Saúde Dr. Ricardo Jorge (Portugal). For that, bacteria were grown in H. pylori selective medium (Biogerm, Maia, Portugal) at 37ºC in a microaerobic environment (Anoxomat®, MART Microbiology BV, Drachten, The Netherlands) for 24 h. For Leifson staining analysis, a drop of each bacterial suspension (in PBS) was spread in cleaned microscope slides, stained with the Leifson dye solution until a golden film developed on the dye surface and a precipitate appeared throughout the sample, and analysed by optical microscopy. For Transmission-Electronic-Microscopy (TEM) studies bacterial pellets were fixed sequentially in glutaraldehyde, osmium tetroxide and uranyl acetate, dehydrated in ethanol and embedded in Epon-Araldite. Thin sections contrasted with uranyl acetate and lead citrate were observed with a JEOL 100-SX electron microscope.Corroborating the better swimming abilities of the PUD strains, as previously shown by motility assays, optical microscopy analysis of Leifson stained slides demonstrated marked differences in the morphology of the studied strains (Figure 1). The H. pylori strain associated with DU (Hp 1152/04) seem longer than all the others and, in contrast, that associated with GU (Hp 499/02) is the shortest one and presents a, more pronounced, spiral morphology. Moreover, our preliminary data on TEM analysis indicate the presence of more abundant and apparently more organized flagella in the GU-associated strain Hp 499/02, in contrast to the NUD control strain, Hp 655/99 (Figure 2).Work supported by Research Grant 2011 – Sociedade Portuguesa de Gastrenterologia.

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Use of Thiols in the Treatment of COVID-19: Current Evidence

Lung ◽

10.1007/s00408-021-00465-3 ◽

2021 ◽

Author(s):

Mario Cazzola ◽

Paola Rogliani ◽

Sundeep Santosh Salvi ◽

Josuel Ora ◽

Maria Gabriella Matera

Keyword(s):

Oxidative Stress ◽

Influenza Virus Infection ◽

Current Evidence ◽

Low Molecular Weight ◽

Oxygen Species ◽

Cytokine Storm ◽

Antioxidant Defences ◽

Antioxidant Molecule ◽

Novel Therapeutic

AbstractThere is a possible role for oxidative stress, a state characterized by an altered balance between the production of free radicals or reactive oxygen species (ROS) and antioxidant defences, in coronavirus disease 2019 (COVID-19), the genesis of which is quite complex. Excessive oxidative stress could be responsible for the alveolar damage, thrombosis, and red blood cell dysregulation observed in COVID-19. Apparently, deficiency of glutathione (GSH), a low-molecular-weight thiol that is the most important non-enzymatic antioxidant molecule and has the potential to keep the cytokine storm in check, is a plausible explanation for the severe manifestations and death in COVID-19 patients. Thiol drugs, which are considered mucolytic, also possess potent antioxidant and anti-inflammatory properties. They exhibit antibacterial activity against a variety of medically important bacteria and may be an effective strategy against influenza virus infection. The importance of oxidative stress during COVID-19 and the various pharmacological characteristics of thiol-based drugs suggest a possible role of thiols in the treatment of COVID-19. Oral and intravenous GSH, as well as GSH precursors such as N-acetylcysteine (NAC), or drugs containing the thiol moiety (erdosteine) may represent a novel therapeutic approach to block NF-kB and address the cytokine storm syndrome and respiratory distress observed in COVID-19 pneumonia patients

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Thermal selection of PGM allozymes in newly founded populations of the thermotolerant vent polychaete Alvinella pompejana

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2004.2852 ◽

2004 ◽

Vol 271 (1555) ◽

pp. 2351-2359 ◽

Cited By ~ 18

Author(s):

P. Piccino ◽

F. Viard ◽

P. Sarradin ◽

N. Le Bris ◽

D. Le Guen ◽

...

Keyword(s):

Alvinella Pompejana ◽

Selection Of

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Antioxidant strategies for Alzheimer's disease

Proceedings of The Nutrition Society ◽

10.1079/pns2002146 ◽

2002 ◽

Vol 61 (2) ◽

pp. 191-202 ◽

Cited By ~ 110

Author(s):

Michael Grundman ◽

Patrick Delaney

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Vitamin E ◽

Oxidative Damage ◽

Functional Decline ◽

Antioxidant Properties ◽

Epidemiological Studies ◽

Clinical Value ◽

Antioxidant Defences ◽

Ad Prevention

Oxidative damage is present within the brains of patients with Alzheimer's disease (AD), and is observed within every class of biomolecule, including nucleic acids, proteins, lipids and carbohydrates. Oxidative injury may develop secondary to excessive oxidative stress resulting from β-amyloid-induced free radicals, mitochondrial abnormalities, inadequate energy supply, inflammation or altered antioxidant defences. Treatment with antioxidants is a promising approach for slowing disease progression to the extent that oxidative damage may be responsible for the cognitive and functional decline observed in AD. Although not a uniformly consistent observation, a number of epidemiological studies have found a link between antioxidant intake and a reduced incidence of dementia, AD and cognitive decline in elderly populations. In AD clinical trials molecules with antioxidant properties such as vitamin E andGinkgo bilobaextract have shown modest benefit. A clinical trial with vitamin E is currently ongoing to determine if it can delay progression to AD in individuals with mild cognitive impairment. Combinations of antioxidants might be of even greater potential benefit for AD, especially if the agents worked in different cellular compartments or had complementary activity (e.g. vitamins E, C and ubiquinone). Naturally-occurring compounds with antioxidant capacity are available and widely marketed (e.g. vitamin C, ubiquinone, lipoic acid, β-carotene, creatine, melatonin, curcumin) and synthetic compounds are under development by industry. Nevertheless, the clinical value of these agents for AD prevention and treatment is ambiguous, and will remain so until properly designed human trials have been performed.

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Identification and Molecular Characterization of Superoxide Dismutases Isolated From A Scuticociliate Parasite: Physiological Role in Oxidative Stress

Scientific Reports ◽

10.1038/s41598-019-49750-5 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Iria Folgueira ◽

Jesús Lamas ◽

Ana Paula de Felipe ◽

Rosa Ana Sueiro ◽

José Manuel Leiro

Keyword(s):

Oxidative Stress ◽

Physiological Role ◽

Host Immune System ◽

Farmed Fish ◽

Free Living ◽

Antioxidant Defences ◽

Sod Activity ◽

Cellular Protection ◽

Facultative Parasite ◽

Copper Zinc

Abstract Philasterides dicentrarchi is a free-living microaerophilic scuticociliate that can become a facultative parasite and cause a serious parasitic disease in farmed fish. Both the free-living and parasitic forms of this scuticociliate are exposed to oxidative stress associated with environmental factors and the host immune system. The reactive oxygen species (ROS) generated by the host are neutralized by the ciliate by means of antioxidant defences. In this study we aimed to identify metalloenzymes with superoxide dismutase (SOD) activity capable of inactivating the superoxide anion (•O2−) generated during induction of oxidative stress. P. dicentrarchi possesses the three characteristic types of SOD isoenzymes in eukaryotes: copper/zinc-SOD, manganese-SOD and iron-SOD. The Cu/Zn-SOD isoenzymes comprise three types of homodimeric proteins (CSD1-3) of molecular weight (MW) 34–44 kDa and with very different AA sequences. All Cu/Zn-SODs are sensitive to NaCN, located in the cytosol and in the alveolar sacs, and one of them (CSD2) is extracellular. Mn- and Fe-SOD transcripts encode homodimeric proteins (MSD and FSD, respectively) in their native state: a) MSD (MW 50 kDa) is insensitive to H2O2 and NaN3 and is located in the mitochondria; and b) FSD (MW 60 kDa) is sensitive to H2O2, NaN3 and the polyphenol trans-resveratrol and is located extracellularly. Expression of SOD isoenzymes increases when •O2− is induced by ultraviolet (UV) irradiation, and the increase is proportional to the dose of energy applied, indicating that these enzymes are actively involved in cellular protection against oxidative stress.

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Enzymic Approach to Eurythermalism of Alvinella pompejana and Its Episymbionts

Applied and Environmental Microbiology ◽

10.1128/aem.01960-07 ◽

2007 ◽

Vol 74 (3) ◽

pp. 774-782 ◽

Cited By ~ 6

Author(s):

Charles K. Lee ◽

S. Craig Cary ◽

Alison E. Murray ◽

Roy M. Daniel

Keyword(s):

Equilibrium Model ◽

Enzyme Stability ◽

Active Form ◽

Thermal Adaptation ◽

Thermal Characteristics ◽

Dorsal Surface ◽

Thermal Conditions ◽

Temperature Adaptation ◽

Model Parameters ◽

Alvinella Pompejana

ABSTRACT The equilibrium model, which describes the influence of temperature on enzyme activity, has been established as a valid and useful tool for characterizing enzyme eurythermalism and thermophily. By introducing K eq, a temperature-dependent equilibrium constant for the interconversion between Eact, the active form of enzyme, and Einact, a reversibly inactive form of enzyme, the equilibrium model currently provides the most complete description of the enzyme-temperature relationship; its derived parameters are intrinsic and apparently universal and, being derived under reaction conditions, potentially have physiological significance. One of these parameters, T eq, correlates with host growth temperature better than enzyme stability does. The vent-dwelling annelid Alvinella pompejana has been reported as an extremely eurythermal organism, and the symbiotic complex microbial community associated with its dorsal surface is likely to experience similar environmental thermal conditions. The A. pompejana episymbiont community, predominantly composed of epsilonproteobacteria, has been analyzed metagenomically, enabling direct retrieval of genes coding for enzymes suitable for equilibrium model applications. Two such genes, coding for isopropylmalate dehydrogenase and glutamate dehydrogenase, have been isolated from the A. pompejana episymbionts, heterologously expressed, and shown by reverse transcription-quantitative PCR to be actively expressed. The equilibrium model parameters of characterized expression products suggested that enzyme eurythermalism constitutes part of the thermal adaptation strategy employed by the episymbionts. Moreover, the enzymes' thermal characteristics correspond to their predicted physiological roles and the abundance and expression of the corresponding genes. This paper demonstrates the use of the equilibrium model as part of a top-down metagenomic approach to studying temperature adaptation of uncultured organisms.

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