scholarly journals Cryptococcus neoformans Mitochondrial Superoxide Dismutase: an Essential Link between Antioxidant Function and High-Temperature Growth

2005 ◽  
Vol 4 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Steven S. Giles ◽  
Ines Batinić-Haberle ◽  
John R. Perfect ◽  
Gary M. Cox

ABSTRACT Manganese superoxide dismutase is an essential component of the mitochondrial antioxidant defense system of most eukaryotes. In the present study, we used a reverse-genetics approach to assess the contribution of the Cryptococcus neoformans manganese superoxide dismutase (Sod2) for antioxidant defense. Strains with mutations in the SOD2 gene exhibited increased susceptibility to oxidative stress as well as poor growth at elevated temperatures compared to isogenic wild-type strains. The sod2Δ mutants were also avirulent in a murine model of inhaled cryptococcosis. Reconstitution of a sod2Δ mutant restored Sod2 activity, eliminated the oxidative stress and temperature-sensitive (ts) phenotypes, and complemented the virulence phenotype. Characterization of the ts phenotype revealed a dependency between Sod2 antioxidant activity and the ability of C. neoformans cells to adapt to growth at elevated temperatures. The ts phenotype could be suppressed by the addition of either ascorbic acid (10 mM) or Mn salen (200 μM) at 30°C, but not at 37°C. Furthermore, sod2Δ mutant cells that were incubated for 24 h at 37°C under anaerobic, but not aerobic, conditions were viable when shifted to the permissive conditions of 25°C in the presence of air. These data suggest that the C. neoformans Sod2 is a major component of the antioxidant defense system in this human fungal pathogen and that adaptation to growth at elevated temperatures is also dependent on Sod2 activity.

2020 ◽  
Vol 7 (4) ◽  
pp. 164-167
Author(s):  
Olga Kovalyova ◽  
Tamara Pasiieshvili

Background. Despite numerous studies, the pathogenesis of gastroesophageal reflux disease remains unclear. Aim of research: assessment the activity of antioxidant defense system in young patients with GERD based on expression of biomarker associated with mitochondrial function. Material and methods. The study included 45 patients with gastroesophageal reflux disease. The examined contingent was presented by students age from 18 to 25 years. 20 healthy persons were included as control group. Levels of manganese superoxide dismutase were determined in blood serum of study persons with enzyme immunoassays (ELISA, Elabscience, USA). Statistical data processing by the Statistica Basic Academic 13 for Windows En local was made. Results. Gastroesophageal reflux disease in young patients is characterized by significantly increasing of manganese superoxide dismutase as compare to control group (7.1700 ng/ml vs 4.4720 ng/ml respectively, p<0.01). Presence of erosion in esophagus mucous doesn't accompanied by significant changes of evaluated parameter as compare with non-erosion form of disease in patients. Conclusion. The elevation in young patients with GERD the biomarker of mitohondrial antioxidant defense system we may speculate as adaptive response contributing to non-specific citoprotection. Taking to account the publishing facts about dual role of manganese superoxide dismutase it is necessary to monitoring antioxidant enzyme in patients with gastroesophageal reflux disease for prediction of possible complications and outcome.


2017 ◽  
Vol 109 (1) ◽  
pp. 53
Author(s):  
Akbar Norastehnia ◽  
Parvaneh SHEYDAEI

<p>Chlorine is one of the ions contributing to salinity, despite being an essential micronutrient. Cl<sup>-</sup> absorption takes place more easily than other nutrients so, the toxic effects of chlorine on the growth has considered rather than its scarcity. Salt stress can ultimately leads to oxidative stress through ROS increase and antioxidant defense system is induced. Therefore, in this study the effect of different concentration of chlorine in irrigation water on the expression of manganese superoxide dismutase was investigated as an indicator of antioxidant defense system activation. Seedlings of tobacco were treated with different concentrations, i.e. 2, 4, 8 mM of CaCl<sub>2</sub>. Evaluation of Mn-SOD isoenzyme gene expression was performed using RT-qPCR (quantitative reverse transcription PCR) at 0, 3, 6 and 12 hours after treatment. The results showed Mn-SOD gene transcription increased after 3 h treatment with 8 mM CaCl<sub>2</sub> and peaked at 6 hours. Based on the observed changes, concentrations of calcium chloride greater than 8 mM in water used for irrigation of tobacco causes stress that results in activation of antioxidant response.</p>


2017 ◽  
Vol 67 (4) ◽  
pp. 540-550 ◽  
Author(s):  
Nataša Popović ◽  
B. Snežana Pajović ◽  
Vesna Stojiljković ◽  
Ana Todorović ◽  
Snežana Pejić ◽  
...  

AbstractThis study examined the effects of chronic restraint stress (CRS: 2 hours × 14 days) on gene expression of three antioxidant enzymes, copper, zinc superoxide dismutase (SOD 1), manganese superoxide dismutase (SOD 2) and catalase (CAT) in the rat hippocampus. Also, we examined changes in the activities of SOD 1, SOD 2 and CAT in the hippocampus of chronically stressed rats. Investigated parameters were quantifi ed by using real-time RT-PCR, Western blot analysis and assay of enzymatic activity. We found that CRS did not change mRNA and protein levels of SOD 1 and CAT, but increased mRNA and protein levels of SOD 2. However, CRS treatment increased the enzyme activities of SOD 1, SOD 2 and CAT. Our fi ndings indicate that the increased activity of antioxidant enzymes (SOD 1, SOD 2 and CAT) in the hippocampus may be an important adaptive phenomenon of the antioxidant defense system in chronically stressed rats.


2022 ◽  
Vol 20 (4) ◽  
pp. 63-70
Author(s):  
O. V. Smirnova ◽  
V. V. Tsukanov ◽  
A. A. Sinyakov ◽  
O. L. Moskalenko ◽  
N. G. Elmanova ◽  
...  

Background. The problem of gastric cancer remains unresolved throughout the world, while chronic atrophic gastritis (CAG) increases the likelihood of its development by 15 times. In the Russian Federation, the incidence of gastric cancer (GC) is among the highest, with it prevailing among males. One of the leading mechanisms in molecular pathology of membranes is lipid peroxidation (LPO). The severity of oxidative membrane damage depends on concomitant diseases, contributing to emergence and progression of pathological processes and development of cancer. Currently, the problem of LPO is unsolved in biological systems.The aim of this study was to investigate the state of LPO and antioxidant defense system in CAG and GC. Materials and methods. The parameters were studied in 45 patients with CAG and 50 patients with GC. The control group included 50 practically healthy volunteers without gastrointestinal complaints, who did not have changes in the gastric mucosa according to the fibroesophagogastroduodenoscopy (FEGDS) findings.Results. In patients with CAG, an increase in malondialdehyde, superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase was found in the blood plasma compared with the control group. In patients with CAG, lipid peroxidation was activated, and the malondialdehyde level increased by 3.5 times relative to normal values. At the same time, the body fought against oxidative stress by increasing the activity of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase. All patients with GC showed pronounced oxidative stress in the blood plasma in the form of a 45-fold increase in malondialdehyde. The activity of the main antioxidant enzyme superoxide dismutase was reduced in GC. Catalase was activated, which indicated pronounced oxidative stress, significant damage to blood vessels, and massive cell death. Glutathione-related enzymes (glutathione S-transferase and glutathione peroxidase) and the antioxidant protein ceruloplasmin were activated, which also indicated significant oxidative stress and severe intoxication in patients with GC.Conclusion. Depending on the stage and type of cancer, an in-depth study of lipid peroxidation and factors of the antioxidant defense system can be used to correct therapy and prevent cancer and can serve as markers of progression and prognosis in gastric cancer. 


2011 ◽  
Vol 35 (1) ◽  
pp. 81-87
Author(s):  
I. K. Latif

gainst damage initiated by a variety of endogenous and exogenous compounds. This study was conducted to evaluate the influence of Benzo[α]Pyrene (BαP) administration on the liver antioxidant defense system. Chicks were assigned into five equal groups, as control, tricaprylin group and three groups treated with BαP (1.5 μg, 150 μg or 15 mg/kg BW). Five birds were sacrificed at days 7, 14, 21 and 35 from each group. To assess the liver antioxidant defense system, glutathione (GSH) concentration, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities were employed. It was found that 15 mg of BαP level create significant increase (P<0.05) in the GSH level, GSH-Px, SOD and CAT activities (18.483, 9.88, 69.44 and 89.88 respectively) of broilers at day 7 post-instillation (p.i.) in compared with control (12.392, 6.51, 41.08 and 50.83). Nevertheless, significant decrease (P<0.05) in the GSH level, GSH-Px, SOD and CAT activities at 21 and 35 days. A key finding from this study is that exposure to BαP may induces oxidative stress on the liver and impair the antioxidant defense system in broilers.


2013 ◽  
Vol 304 (5) ◽  
pp. E495-E506 ◽  
Author(s):  
S. Keipert ◽  
M. Ost ◽  
A. Chadt ◽  
A. Voigt ◽  
V. Ayala ◽  
...  

Ectopic expression of uncoupling protein 1 (UCP1) in skeletal muscle (SM) mitochondria increases lifespan considerably in high-fat diet-fed UCP1 Tg mice compared with wild types (WT). To clarify the underlying mechanisms, we investigated substrate metabolism as well as oxidative stress damage and antioxidant defense in SM of low-fat- and high-fat-fed mice. Tg mice showed an increased protein expression of phosphorylated AMP-activated protein kinase, markers of lipid turnover (p-ACC, FAT/CD36), and an increased SM ex vivo fatty acid oxidation. Surprisingly, UCP1 Tg mice showed elevated lipid peroxidative protein modifications with no changes in glycoxidation or direct protein oxidation. This was paralleled by an induction of catalase and superoxide dismutase activity, an increased redox signaling (MAPK signaling pathway), and increased expression of stress-protective heat shock protein 25. We conclude that increased skeletal muscle mitochondrial uncoupling in vivo does not reduce the oxidative stress status in the muscle cell. Moreover, it increases lipid metabolism and reactive lipid-derived carbonyls. This stress induction in turn increases the endogenous antioxidant defense system and redox signaling. Altogether, our data argue for an adaptive role of reactive species as essential signaling molecules for health and longevity.


2009 ◽  
Vol 39 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Jihong Qin ◽  
Qing Liu

In the subalpine zone of the Qinghai–Tibetan Plateau of China, Dragon spruce (Picea asperata Mast.) is commonly used for reforestation. The aim of the present work was to study the effects of seasonally frozen soil on the germination of P. asperata seeds and to investigate whether these effects were associated with resumption of the antioxidant defense system. The nonfrozen treatment resulted in near failure of germination (1%) and was associated with relatively high levels of hydrogen peroxide (H2O2) and low activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxide (APX). Germination of P. asperata seeds at 10 cm under the seasonally frozen soil was higher than that at 5 cm by 26%; this higher germination rate was associated with the recovery of SOD, CAT, and APX activities. The levels of malondialdehyde (MDA) in seeds from seasonally frozen treatments were higher than those in the nonfrozen treatment, implying greater lipid peroxidation and that frozen seeds might have suffered from oxidative stress. The results indicate that seasonally frozen soil facilitated the germination of P. asperata seeds and that germination was closely related to the resumption of antioxidant enzymes activity. Overall, these findings suggest that the disappearance of seasonally frozen ground caused by global warming might result in failure of regeneration of P. asperata.


2021 ◽  
Vol 15 (1) ◽  
pp. 37-48
Author(s):  
D. Yu. Hertsyk ◽  
◽  
M. V. Sabadashka ◽  
L. V. Kaprelyants ◽  
N. O. Sybirna ◽  
...  

Background. Diabetes mellitus is accompanied by oxidative-nitrative stress, which is caused both by an increased generation of the Reactive Oxygen Species and the Reactive Nitrogen Species under the conditions of this pathology and by the disorders of the antioxidant defense system, especially its enzymatic part. This leads alterations in the morpho-functional state of cells, organs, and the whole organism. Free radicals are involved in the destruction of pancreatic cells in type 1 diabetes mellitus, which leads to even greater inhibition of insulin secretion, worsening of the course of the disease and occurrence of diabetic complications. The complications of diabetes mellitus include often diagnosed cardiovascular diseases. Therefore, the use of treatments characterized not only by hypoglycemic properties for normalization of blood sugar level in diabetes mellitus, but also by antioxidant properties for normalization of oxidative/antioxidant balance of the organism in the studied pathology can be promising. Scientists pay a great attention to the study of substances with such properties, especially natural phenolic compounds of grape, which are also characterized by immunomodulatory properties. Materials and Methods. The study was performed on cardiac tissues of control rats, control animals treated with wine polyphenolic complex concentrate, animals with streptozotocin-induced diabetes mellitus and animals with experimental diabetes mellitus treated with a concentrate of wine polyphenolic complex. The activity of catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase were detected to examine the corrective effect of the concentrate of red wine natural polyphenolic comp­lex on the state of the enzymatic part of the antioxidant defense system. Results. The results have shown the normalization of activity of catalase, superoxide dismutase, and changes in the activity of enzymes of glutathione cycle after oral administration of polyphenolic complex concentrate for 14 days to rats with streptozo­tocin-induced diabetes mellitus. Conclusions. The results confirm a hypothesis about the antioxidant effect of the studied concentrate and the ability of natural polyphenolic complexes to serve as the basis for new drugs for treatment of diabetes-induced disorders.


Sign in / Sign up

Export Citation Format

Share Document