scholarly journals Haloadaptative Responses of Aspergillus sydowii to Extreme Water Deprivation: Morphology, Compatible Solutes, and Oxidative Stress at NaCl Saturation

2020 ◽  
Vol 6 (4) ◽  
pp. 316
Author(s):  
Irina Jiménez-Gómez ◽  
Gisell Valdés-Muñoz ◽  
Tonatiuh Moreno-Perlin ◽  
Rosa R. Mouriño-Pérez ◽  
María del Rayo Sánchez-Carbente ◽  
...  

Water activity (aw) is critical for microbial growth, as it is severely restricted at aw < 0.90. Saturating NaCl concentrations (~5.0 M) induce extreme water deprivation (aw ≅ 0.75) and cellular stress responses. Halophilic fungi have cellular adaptations that enable osmotic balance and ionic/oxidative stress prevention to grow at high salinity. Here we studied the morphology, osmolyte synthesis, and oxidative stress defenses of the halophile Aspergillus sydowii EXF-12860 at 1.0 M and 5.13 M NaCl. Colony growth, pigmentation, exudate, and spore production were inhibited at NaCl-saturated media. Additionally, hyphae showed unpolarized growth, lower diameter, and increased septation, multicellularity and branching compared to optimal NaCl concentration. Trehalose, mannitol, arabitol, erythritol, and glycerol were produced in the presence of both 1.0 M and 5.13 M NaCl. Exposing A. sydowii cells to 5.13 M NaCl resulted in oxidative stress evidenced by an increase in antioxidant enzymes and lipid peroxidation biomarkers. Also, genes involved in cellular antioxidant defense systems were upregulated. This is the most comprehensive study that investigates the micromorphology and the adaptative cellular response of different non-enzymatic and enzymatic oxidative stress biomarkers in halophilic filamentous fungi.

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Douglas Popp Marin ◽  
Rita de Cassia Macedo dos Santos ◽  
Anaysa Paola Bolin ◽  
Beatriz Alves Guerra ◽  
Elaine Hatanaka ◽  
...  

Background. Handball is considered an intermittent sport that places an important stress on a player's aerobic and anaerobic metabolism. However, the oxidative stress responses following a handball game remain unknown. We investigated the responses of plasma and erythrocyte antioxidant system and oxidative stress biomarkers following a single handball game.Methods. Fourteen male elite Brazilian handball athletes were recruited in the present study. Blood samples were taken before, immediately, and 24 hours after the game.Results. After the game and during 24 hours of recovery, the concentration of all oxidative stress indices changed significantly in a way indicating increased oxidative stress in the blood (thiol groups and reduced glutathione decreased, whereas TBARS and plasma antioxidant capacity was increased) as well as in erythrocyte (increased levels of TBARS and protein carbonyls). Erythrocyte antioxidant enzyme activities were also significantly changed by handball. Muscle damage indices (creatine kinase and lactate dehydrogenase) increased significantly after exercise. In addition, IL-6 increased after the game, whereas TNF-αdecreased during recovery.Conclusion. This study demonstrates that a single handball game in elite athletes induces a marked state of oxidative stress evidenced by the oxidative modification in plasma and erythrocyte macromolecules, as well as by changes in the enzymatic and nonenzymatic antioxidant system.


Author(s):  
Basant Joshi ◽  
Sangeeta Singh ◽  
Preeti Sharma ◽  
Tapan Mohapatra ◽  
Pradeep Kumar

Introduction: Cigarette Smoking (CS) is the single greatest preventable cause of disease and death and is rich in Reactive Oxygen and Nitrogen Species (ROS and RNS). These can cause the production of other free radicals, which, in turn, initiate lipid peroxidation and cause several diseases. Free radical scavenger enzymes namely Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione Peroxidase (GPx) represent the enzymatic part that have the ability to inhibit oxidative stress by scavenging the highly destructive free radicals. Aim: To study the effect of CS on selected antioxidant enzymes and oxidative stress biomarkers. Materials and Methods: A case control study was conducted from September 2016 to September 2019 in which total of 284 healthy (without any systemic diseases) cigarette smokers (cases) in the age group of 18-60 years compared with age and sex matched 284 nonsmokers (controls) were included in the study. Estimation of serum 8-hydroxydeoxyguanosine (8-OHdG) by Enzyme Linked Immunosorbant Assay (ELISA), Malondialdehyde (MDA) by Thiobarbuturic Acid Reactive Substances (TBARS), SOD by water soluble tetrazolium salt 1, GPx and CAT by colorimetric method. The analysis was carried out using the SPSS 19.0.2 program for windows. Unpaired t-test and one-way ANOVA were used to analyse all the data for statistical significance. Results: The mean Serum MDA and 8-OHdG levels were significantly raised 7.47±1.84, 63.41±22.44 as compared to nonsmokers (3.90±1.03, 40.04±20.14) and serum SOD, Gpx and CAT levels were decreased 62.55±19.97, 44.45±16.60 and 12.92±10.16 in cigarette smokers as compared to nonsmokers 274.04±68.37, 208.56±75.63 and 127.82±18.68, respectively. These differences were also found to be statistically significant in cigarette smokers according to duration and number of cigarette smoked at the level of <0.05. Conclusion: Cigarette Smoking, especially long-term smoking may leads to significant changes in the enzymatic antioxidant defense systems of smokers. Discontinuation of smoking and general awareness needs to be created to minimise the risk of smoking related diseases.


Author(s):  
Sinan Xiong ◽  
Wee-Joo Chng ◽  
Jianbiao Zhou

AbstractUnder physiological and pathological conditions, cells activate the unfolded protein response (UPR) to deal with the accumulation of unfolded or misfolded proteins in the endoplasmic reticulum. Multiple myeloma (MM) is a hematological malignancy arising from immunoglobulin-secreting plasma cells. MM cells are subject to continual ER stress and highly dependent on the UPR signaling activation due to overproduction of paraproteins. Mounting evidence suggests the close linkage between ER stress and oxidative stress, demonstrated by overlapping signaling pathways and inter-organelle communication pivotal to cell fate decision. Imbalance of intracellular homeostasis can lead to deranged control of cellular functions and engage apoptosis due to mutual activation between ER stress and reactive oxygen species generation through a self-perpetuating cycle. Here, we present accumulating evidence showing the interactive roles of redox homeostasis and proteostasis in MM pathogenesis and drug resistance, which would be helpful in elucidating the still underdefined molecular pathways linking ER stress and oxidative stress in MM. Lastly, we highlight future research directions in the development of anti-myeloma therapy, focusing particularly on targeting redox signaling and ER stress responses.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Itana Gomes Alves Andrade ◽  
Fabíola Isabel Suano-Souza ◽  
Fernando Luiz Affonso Fonseca ◽  
Carolina Sanchez Aranda Lago ◽  
Roseli Oselka Saccardo Sarni

Abstract Introduction Ataxia-Telangiectasia (A-T) is a multi-system disorder that may be associated with endocrine changes, oxidative stress in addition to inflammation. Studies suggest that selenium is a trace element related to protection against damage caused by oxidative stress. Objective To describe the plasma levels of selenium and erythrocyte glutathione peroxidase activity in A-T patients and to relate them to oxidative stress and lipid status biomarkers. Methods This is a cross-sectional and controlled study evaluating 22 A-T patients (age median, 12.2 years old) matched by gender and age with 18 healthy controls. We evaluated: nutritional status, food intake, plasma selenium levels, erythrocyte glutathione peroxidase activity, lipid status, inflammation and oxidative stress biomarkers. Results Adequate levels of selenium were observed in 24/36 (66.7%) in this evaluated population. There was no statistically significant difference between the groups in selenium levels [47.6 μg/L (43.2–57.0) vs 54.6 (45.2–62.6) μg/dL, p = 0.242]. Nine of A-T patients (41%) had selenium levels below the reference value. The A-T group presented higher levels of LDL-c, non-HDL-c, oxidized LDL, Apo B, Apo-B/Apo-A-I1, LDL-c/HDL-c ratio, malondialdehyde [3.8 µg/L vs 2.8 µg/L, p = 0.029] and lower Apo-A-I1/HDL-c and glutathione peroxidase activity [7300 U/L vs 8686 U/L, p = 0.005]. Selenium levels were influenced, in both groups, independently, by the concentrations of oxidized LDL, malonaldehyde and non-HDL-c. The oxidized LDL (AUC = 0.849) and ALT (AUC = 0.854) were the variables that showed the greatest discriminatory power between groups. Conclusion In conclusion, we observed the presence of selenium below the reference value in nearly 40% and low GPx activity in A-T patients. There was a significant, inverse and independent association between selenium concentrations and oxidative stress biomarkers. Those data reinforce the importance of assessing the nutritional status of selenium in those patients.


2018 ◽  
Vol 9 (12) ◽  
pp. 6508-6516 ◽  
Author(s):  
Marta Esgalhado ◽  
Julie A. Kemp ◽  
Renata Azevedo ◽  
Bruna R. Paiva ◽  
Milena B. Stockler-Pinto ◽  
...  

Prebiotic-resistant starch supplementation may be a good strategy to reduce inflammation, oxidative stress and uremic toxins in CKD patients.


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