Role Of Superoxide Dismutase Research Articles

The Role of SOD, Catalase, HSP-27, HSP-70, and TNF-α Expression in Apoptosis of Retinal Ganglion Cells After Intra Ocular Pressure Increase on Rattus Norvegicus

The aim of this study is to investigate the involvement of Super Oxide Dismutase (SOD), Catalase, Heat Shock Protein 70 (HSP 70), Heat Shock Protein 27 (HSP 27) Retinal Ganglion Cells (RGCs) and Tumor Necrosis Factor ? (TNF-?) microglia in apoptosis RGCs and RGCs survival after transient periode of pressure induced ischemia/reperfussion injury of rat retina.The study design was randomized post test only control groups. Thirty one Sprague Dawley (SPD) rats were divided into 4 groups. 1 control group and 3 experimental groups. Experimental groups were induced by transient elevation of intraocular pressure (IOP) 110-130 mmHg for 45 minutes (7 rats), 60 minutes (7 rats), 75 minutes (7 rats). 28 rats were terminated at day 7 and 3 rats were terminated at first day for histology and immunohistochemistry staining examination. Result from the Expression of SOD, HSP 70 GSRs and TNF-? microglia were significantly different. p=0,046 and B=0.380 for SOD; p=0.030 and B=0,411 for Hsp 70; p=0.007 and B=0,501 for TNF-?. Expression of catalase and HSP 27 GRCs were not significantly different. p=0.203 for catalase; p=0.083 for Hsp 27. The increased expression of HSP 70 indicated strong correlation with increased level of apoptosis RGCs, p=0.046 and B=0,473. In conclusion, the result demonstrated that RGCs apoptosis survival in glaucoma correlates strongly with transient elevated IOP and is significantly associated with IOP induced changes in expression HSP 70 RGCs.

Enzymatic Analysis of Superoxide Dismutase (SOD) from Hordeum vulgare: Its Role in Drought Stress Tolerance

Superoxide dismutases (SODs) are ubiquitous metalloenzymes that constitute the first line of defense against reactive oxygen species. The role of SOD in neutralizing free radical production has already been documented. In the present investigation we have attempt to study kinetic properties of SODs in three drought sensitive and drought resistant varieties of H. vulgare. The results demonstrated that SOD displayed decreased affinities of substrate binding to their corresponding enzymes under drought conditions. The SOD isozymes profile was also analyzed and it was found that under drought conditions the only two SOD isozymes expressed as against three isozymes expressed under control. These data suggest that the decreased substrate binding affinity to SODs as well as decrease in one isozyme band of SOD under drought condition may be responsible for resistance. These findings may be used to develop drought resistance varieties of other crops.

English

Recent agriculture is characterized by intensive and cleaning productions, which need seeds with high quality in large quantities bonded by in vitro culture labs. Nevertheless, in vitro ex vitro transition and during acclimatization losses occur due to the death of plantlets unable to survive this abiotic stress. Reactive oxygen species production during jasmonic acid-induced changes of previous transition was demonstrated. The role of superoxide dismutase in regulation of oxidative metabolism signaling in response to environmental stress is analyzed. Pineapple plantlets treated with jasmonic acid showed higher protein biosynthesis, which can be associated with a better regulated metabolic predisposition to face this phase, when superoxide dismutase activity showed adequate control against this stress in relation to superior water-use efficiency and survival. Key words: Environmental stress, water-use efficiency, survival.

Functional analysis of superoxide dismutase of Salmonella typhimurium in serum resistance and biofilm formation.

Further investigations of the novel biological functions of SodA in Salmonella enterica serovar typhimurium (Salm. typhimurium). A deletion mutant of sodA in Salm. typhimurium was constructed and its biological characteristics were analysed. More specifically, the roles of superoxide dismutase (SOD) in resistance to environmental stresses and serum, biofilm formation, epithelial cell adherence and invasion were investigated. Inactivation of sodA gene resulted in a slightly reduced growth rate, low SOD activity and increased susceptibility to reactive oxygen species and chicken serum. However, SodA was not involved in the motility of Salm. typhimurium. In addition, the sodA mutant exhibited a decreased capacity to form biofilm as well as to adhere and invade to HeLa cells, compared to the wild-type and complemented strains. Salmonella typhimurium SOD appears to play an important role in resistance to serum and oxidative stress, biofilm formation, adherence to and invasion of epithelial cells. This study illustrates the novel roles of SodA in serum resistance and biofilm formation in Salm. typhimurium, which may provide a candidate for the biofilm eradication and prevention of infections.

Superoxide dismutase 3 protects mesenchymal stem cells through enhanced autophagy and regulation of FoxO3a trafficking

Therapeutic applications of mesenchymal stem cells (MSCs) are limited due to their early death within the first few days of transplantation. Therefore, to improve the efficacy of cell-based therapies, it is necessary to manipulate MSCs so that they can resist various stresses imposed by the microenvironment. Moreover, the role of superoxide dismutase 3 (SOD3) in regulating such survival under different stress conditions remain elusive. In this study, we overexpressed SOD3 in MSCs (SOD3-MSCs) and evaluated its effect under serum starvation conditions. Nutritional limitation can decrease the survival rate of transplanted MSCs and thus can reduce their efficacy during therapy. Interestingly, we found that SOD3-MSCs exhibited reduced reactive oxygen species levels and greater survival rates than normal MSCs under serum-deprived conditions. In addition, overexpression of SOD3 attenuated starvation-induced apoptosis with increased autophagy in MSCs. Moreover, we have demonstrated that SOD3 protects MSCs against the negative effects of serum deprivation via modulation of AMP-activated protein kinase/sirtulin 1, extracellular signal-regulated kinase activation, and promoted Forkhead box O3a trafficking to the nucleus. Taken together, these results demonstrate that SOD3 promotes MSCs survival and add further evidence to the concept that SOD3-MSCs may be a potential therapeutic agent with better outcomes than normal MSCs for various diseases involving oxidative stress and compromised MSCs survival during therapy.

Chemotherapy-Induced Tissue Injury: An Insight into the Role of Extracellular Vesicles-Mediated Oxidative Stress Responses.

The short- and long-term side effects of chemotherapy limit the maximum therapeutic dose and impair quality of life of survivors. Injury to normal tissues, especially chemotherapy-induced cardiomyopathy, is an unintended outcome that presents devastating health impacts. Approximately half of the drugs approved by the Food and Drug Administration for cancer treatment are associated with the generation of reactive oxygen species, and Doxorubicin (Dox) is one of them. Dox undergoes redox cycling by involving its quinone structure in the production of superoxide free radicals, which are thought to be instrumental to the role it plays in cardiomyopathy. Dox-induced protein oxidation changes protein function, translocation, and aggregation that are toxic to cells. To maintain cellular homeostasis, oxidized proteins can be degraded intracellularly by ubiquitin-proteasome pathway or by autophagy, depending on the redox status of the cell. Alternatively, the cell can remove oxidized proteins by releasing extracellular vesicles (EVs), which can be transferred to neighboring or distant cells, thereby instigating an intercellular oxidative stress response. In this article, we discuss the role of EVs in oxidative stress response, the potential of EVs as sensitive biomarkers of oxidative stress, and the role of superoxide dismutase in attenuating EV-associated oxidative stress response resulting from chemotherapy.

The role of superoxide dismutase on pregnancy rates of women undergoing intrauterine insemination

Background: Recently, assisted reproductive technology has been widely accepted as a well-established procedure to treat infertility. Unfortunately, the success rate is still below expectations, whereas the rate of infertility has risen steadily. Intrauterine insemination procedure is the highest performed compared to other procedures, but the success rate is still lowest, around 10%. One cause of failure has been thought to occur due to lack of oocytes and embryos protection from cleaning of oxygen radicals. Reactive oxygen species negatively affect the maturation and interaction of gamete, fertilization, as well as acceleration of pathological states of the reproductive tract. On female reproduction, an antioxidant is essential for the maturation and quality of oocyte, implantation, placentation, fetal growth, and development of the organ. Concentrations of antioxidants have an important role in the reproduction, and interventions to reduce the influence of reactive oxygen species can improve the quality of embryos and their implantation.Objective: To determine the effect of antioxidants (superoxide dismutase [SOD]) in ovarian stimulation response and pregnancy rates in women undergoing intrauterine insemination.Material: Women undergoing intrauterine insemination procedures and who met the criteria of research were randomly and in double-blind divided into two groups, that is, SOD group and placebo group. During ovarian stimulation, 20 patients randomly selected were administered capsules containing 250 mg SOD (glisodin®, Kalbe Pharmaceutical, tbk.) twice a day, and the remaining 20 patients were given the same dose and color capsules containing placebo. Furthermore, ovarian activity and endometrial thickness were monitored by regular transvaginal ultrasound scans. A dose of 5000 U of hCG (Profasi, Serono Pharmaceuticals Ltd., UK) was administered when the leading cohort of follicles reached a diameter of 18–22 mm. Intrauterine insemination with prepared sperms was then performed 34–36 hours following hCG using Friedman catheter. Biochemical pregnancy is determined at day 15 after insemination with the cut-off point 25I U/mL. The data are compared between two groups and analyzed using SPSS 16 with a 95% confidence interval.Result: Forty women underwent intrauterine insemination cycles, with 20 cycles administered to each group, SOD and placebo. There were five (12.5%) positives for chemical pregnancies, four (80%) in SOD, and one (20%) in placebo. The pregnancy rates tend to be higher in the SOD group than in the placebo group, even though it was not significantly different (p = 0.151). The ovarian stimulation determined by the number of growing follicles and endometrial thickness showed that more follicles (≥ 6 follicles) were found in SOD group (n = 10, 58.8%) than in placebo (n = 7, 41.2%); however, it was not statistically significant (p = 0.075). Endometrial thickness of 10 mm or more is statistically significant (p = 0.017), which is higher (79.2%) in SOD compared with placebo (20.8%) and yields significantly (p = 0.0251) greater pregnancy rates (n = 4, 80%) than placebo (n = 1, 20%).Conclusions: SOD provides better stimulation response and increased pregnancy rates in intrauterine insemination program.

A cytoplasmic Cu-Zn superoxide dismutase SOD1 contributes to hyphal growth and virulence of Fusarium graminearum

Superoxide dismutases (SODs) are scavengers of superoxide radicals, one of the main reactive oxygen species (ROS) in the cell. SOD-based ROS scavenging system constitutes the frontline defense against intra- and extracellular ROS, but the roles of SODs in the important cereal pathogen Fusarium graminearum are not very clear. There are five SOD genes in F. graminearum genome, encoding cytoplasmic Cu-Zn SOD1 and MnSOD3, mitochondrial MnSOD2 and FeSOD4, and extracellular CuSOD5. Previous studies reported that the expression of SOD1 increased during infection of wheat coleoptiles and florets. In this work we showed that the recombinant SOD1 protein had the superoxide dismutase activity in vitro, and that the SOD1-mRFP fusion protein localized in the cytoplasm of F. graminearum. The Δsod1 mutants had slightly reduced hyphal growth and markedly increased sensitivity to the intracellular ROS generator menadione. The conidial germination under extracellular oxidative stress was significantly delayed in the mutants. Wheat floret infection assay showed that the Δsod1 mutants had a reduced pathogenicity. Furthermore, the Δsod1 mutants had a significant reduction in production of deoxynivalenol mycotoxin. Our results indicate that the cytoplasmic Cu-Zn SOD1 affects fungal growth probably depending on detoxification of intracellular superoxide radicals, and that SOD1-mediated deoxynivalenol production contributes to the virulence of F. graminearum in wheat head infection.

A wheat superoxide dismutase gene TaSOD2 enhances salt resistance through modulating redox homeostasis by promoting NADPH oxidase activity.

Superoxide dismutase (SOD) is believed to enhance abiotic stress resistance by converting superoxide radical (O2 (-)) to H2O2 to lower ROS level and maintain redox homeostasis. ROS level is controlled via biphasic machinery of ROS production and scavenging. However, whether the role of SOD in abiotic stress resistance is achieved through influencing the biophasic machinery is not well documented. Here, we identified a wheat copper-zinc (Cu/Zn) SOD gene, TaSOD2, who was responsive to NaCl and H2O2. TaSOD2 overexpression in wheat and Arabidopsis elevated SOD activities, and enhanced the resistance to salt and oxidative stress. TaSOD2 overexpression reduced H2O2 level but accelerated O2 (-) accumulation. Further, it improved the activities of H2O2 metabolic enzymes, elevated the activity of O2 (-) producer NADPH oxidase (NOX), and promoted the transcription of NOX encoding genes. The inhibition of NOX activity and the mutation of NOX encoding genes both abolished the salt resistance of TaSOD2 overexpression lines. These data indicate that Cu/Zn SOD enhances salt resistance, which is accomplished through modulating redox homeostasis via promoting NOX activity.

Role of superoxide dismutase in hepatitis B virus-related hepatocellular carcinoma.

Background:Reactive oxygen species (ROS) play important roles in hepatocarcinogenesis. Superoxide dismutase (SOD) is involved in the repair of ROS. Serum alpha-fetoprotein (AFP) is the “golden marker” for diagnosing hepatocellular carcinoma (HCC), and one major shortcoming of its use is that it is insensitive for the early detection of HCC. Therefore, we evaluated serum SOD levels and their association with AFP in hepatitis B virus (HBV)-related HCC.Materials and Methods:A total of 279 subjects were divided into three groups: 99 HBV patients with HCC, 73 HBV patients without HCC, and 107 sex- and age-matched healthy controls. Serum levels of SOD were assayed using colorimetry, while AFP levels were measured by electrochemiluminescence immunoassay.Results:A highly significant elevation was found in AFP in HBV-with HCC patients compared to HBV-without HCC patients and control subjects (P < 0.001). Alternatively, serum SOD levels were significantly decreased in patients with HCC compared to HBV patients without HCC and healthy controls (P < 0.001). Furthermore, serum SOD was negatively correlated with AFP (r = −0.505, P < 0.001) in HBV-with HCC patients.Conclusion:SOD and AFP might be simultaneously evaluated to improve the HCC detection rate.

Redox status of extremophilic yeast Yarrowia lipolytica during adaptation to pH-stress

In this study we investigated the activities of antioxidant enzymes (superoxide dismutases (SODs) and catalases (CATs)) and the ROS level in cells of Yarrowia lipolytica yeasts grown in a medium with different pH values (4.5, 5.5 and 9.0). It was shown that an increase in the cellular ROS level took place under both acid and alkaline conditions. The growth under extreme conditions was accompanied by a significant increase of SOD activity (by 2.5 times in the acid medium and by 4 times in the alkaline medium), but catalase activity did not change. A study of the electrophoretic profile of catalases showed the presence of three isoforms differing in inhibitor resistance. The electrophoretic profiles of SODs and their inhibitory analysis revealed there are two other isoforms, probably of mitochondrial origin, in addition to Cu and Zn SOD. The role of SOD in pH-adaptation of extremophilic Y. lipolytica yeasts is discussed.

Identification and characterization of a PutCu/Zn-SOD gene from Puccinellia tenuiflora (Turcz.) Scribn. et Merr.

The role of superoxide dismutase (SOD) in organismal stress conditions has been widely reported. However, little is known concerning the function of superoxide dismutase in Puccinellia tenuiflora (Turcz.) Scribn. et Merr. In this study, PutCu/Zn-SOD, a cDNA clone that encodes a copper–zinc superoxide dismutase gene, was derived from a cDNA library of P. tenuiflora treated with NaHCO3. Nucleotide sequence analysis revealed that the PutCu/Zn-SOD gene cDNA clone consisted of 615 bp encoding a protein with 204 amino acids. In transformed Arabidopsis protoplasts, a PutCu/Zn-SOD protein was located in the chloroplasts as revealed by a green fluorescent protein. Real-time quantitative PCR expression analysis revealed that the PutCu/Zn-SOD gene was expressed in leaves and roots. PutCu/Zn-SOD gene expression was inducible by 60 mM NaHCO3, 150 mM NaCl, and 1.8 mM H2O2. The differential mRNA expression of PutCu/Zn-SOD was observed for leaves and roots exposed to salinity, alkalinity or oxidative stress. The overexpression of PutCu/Zn-SOD gene in transgenic yeast and Arabidopsis plants increased resistance to multiple abiotic stresses. Transgenic Arabidopsis seedlings exhibited elevated total SOD activity. This study suggested that PutCu/Zn-SOD gene can play an important role in multiple stress.

Down-regulation of superoxide dismutase 1 by PMA is involved in cell fate determination and mediated via protein kinase D2 in myeloid leukemia cells

Myeloid leukemia cells maintain a high intracellular ROS level and use redox signals for survival. The metabolism of ROS also affects cell fate, including cell death and differentiation. Superoxide dismutases (SODs) are major antioxidant enzymes that have high levels of expression in myeloid leukemia cells. However, the role of SODs in the regulation of myeloid leukemia cells' biological function is still unclear. To investigate the function of SODs in myeloid leukemia cell death and differentiation, we used myeloid leukemia cell lines K562, MEG-01, TF-1, and HEL cells for this study. We found that PMA-induced megakaryocytic differentiation in myeloid leukemia cells is accompanied by cell death and SOD1 down-regulation, while SOD2 expression is not affected. The role of SOD1 is verified when ATN-224, a SOD1 specific inhibitor, inhibits cell proliferation and promotes cell death in myeloid leukemia cells without PMA treatment. Moreover, inhibition or silencing of SODs further increases cell death and decreases polyploidization induced by PMA while they were partially reversed by SOD1 overexpression. Thus, SOD1 expression is required for myeloid leukemia cell fate determination. In addition, the knockdown of PKD2 reduces cell death and promotes polyploidization induced by PMA. PMA/PKD2-mediated necrosis via PARP cleavage involves both SOD1-dependent and -independent pathways. Finally, ATN-224 enhanced the inhibition of cell proliferation by Ara-C. Taken together, the results demonstrate that SOD1 regulates cell death and differentiation in myeloid leukemia cells. ATN-224 may be beneficial for myeloid leukemia therapy.

Abstract B01: Superoxide dismutase significantly reversed the development of cisplatin resistance in epithelial ovarian cancer

Abstract Background: We have previously demonstrated that cisplatin resistant epithelial ovarian cancer (EOC) cells manifest a severe prooxidant state, which may be responsible for the maintenance of the resistant oncogenic phenotype. Objective: The objective of this study was to determine whether superoxide dismutase (SOD), a key antioxidant, could delay the development of cisplatin resistance in EOC cells. Methods: Human EOC cell lines, SKOV-3 and MDAH-2774 were utilized for this study. Cells were divided into three groups; untreated, cisplatin treated controls, and combined treated cisplatin plus SOD (20 U/ml). Control cells were cultured in the presence of a stepwise increase in cisplatin (0.25 μM increments every 72 hours up to a final dose of 1 μM). Combined treated cells were cultured in the same fashion as controls except for the addition of 20 U/ml SOD every 72 hours. Cells were considered resistant to cisplatin when a significantly similar or greater fold change of live cells was observed despite an increase in the concentration of cisplatin as compared to the untreated cells. The number of live and dead cells was determined every 72 hours, utilizing the Trypan blue dye exclusion method. Statistical analysis: Z-scores were used for statistical analysis at p-value &amp;lt;0.05 for significance. Z-scores probability distribution were generated from the untreated cells and cisplatin-treated cells for both MDAH-2774 and SKOV-3 lines. Results: Results: Both EOC cell lines developed cisplatin resistance at a concentration of 1 μM following several passages over a two-week period; as demonstrated by a nonstatistically significantly fold change of live cells (1.00 untreated cells vs. 1.56 cisplatin-treated controls for MDAH-2774, p&amp;gt;0.05 two-tailed; 2.81 untreated cells vs. cisplatin-treated controls 1.53 in SKOV-3, p&amp;gt;0.05 two-tailed). Similarly, combined treatment cells demonstrated cisplatin resistance at a concentration of 1 μM (1.00 untreated cells vs. 24.75 SOD+cisplatin-treated controls for MDAH-2774, p&amp;gt;0.05 two-tailed; 2.81 untreated cells vs. 1.00 SOD+cisplatin-treated controls 1.00 for SKOV-3, p&amp;gt;0.05 two-tailed). However, with increasing concentrations of SOD (40 and then 60 U/ml) there was a significant decrease in the fold change of live cells (23.75 cisplatin-treated controls versus 1.00 SOD+cisplatin-treated (p&amp;lt;0.05), 8.42 cisplatin-treated controls versus 1.00 SOD+cisplatin-treated for MDAH-2774 (p&amp;gt;0.05); 1.45 cisplatin-treated controls versus 1.00 SOD+cisplatin-treated (p&amp;gt;0.05), 1.00 SOD+cisplatin-treated versus 0.97 cisplatin-treated controls (p&amp;gt;0.05), at 40 and 60 U/ml respectively in SKOV-3). Conclusion: Our results indicate a potential role for SOD in protecting against the acquisition of chemoresistance in ovarian cancer cells and may serve as a potential therapeutic intervention in combination with chemotherapy treatment. Citation Format: Jimmy Belotte, Osama Nusrat, Nicole F. Fletcher, Mohammed G. Saed, Bailey Neubauer, Husam M. Abu-Soud. Superoxide dismutase significantly reversed the development of cisplatin resistance in epithelial ovarian cancer. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Drug Sensitivity and Resistance: Improving Cancer Therapy; Jun 18-21, 2014; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(4 Suppl): Abstract nr B01.

Role of superoxide dismutases and alkyl hydroperoxidases in pathogenesis of Pseudomonas syringae (741.1)

Plants, such as Arabidopsis thaliana, release reactive oxygen species (ROS) such as the superoxide anion, hydroxyl radical, and hydroxyl ion as a defense mechanism when they are infected with microorganisms. The production of ROS results in restriction of the growth of pathogens like Pseudomonas syringae. In order to be a successful pathogen, P. syringae must suppress these responses when it infects plants. P. syringae has evolved redox‐related enzymes to detoxify ROS. The sods and Ahps are able to relieve oxidative stresses by detoxifying ROS into less reactive molecules using these redox‐related enzymes during infection. However, it remains unclear whether Sods and Ahp(s) also play a role in pathogenesis.In this project, we set out to1) Clone and express sodA, sodB and sodC genes in E. coli, 2) Perform pathogenicity assay with the sodC mutant, and 3) Generate deletion mutants lacking both AhpC and AhpF. We successfully cloned the sodA, sodB and sodC genes using plasmid pLN615, and verified their authenticity by immunoblot of the expression extract. Pathogenicity assays revealed that the sodC mutant did not show significant differences in virulence from the wild type strain DC3000 in Arabidopsis plants. This suggests that the sodC gene may be redundant with the sodA and sodB in DC3000. We were also successful in generating P. syringae mutant lacking both AhpC and AhpF using an unmarked mutagenesis approach.Grant Funding Source: NSF

The role of superoxide dismutase (SOD) in skin disorders A review

Environmental stress factors attack body cells daily. As skin is the first barrier to exogenous threats, such as UV exposure, chemicals and pathogens, a proper strategy to prevent skin inflammation is necessary. As the environment tends to strip away the nutrients essential to maintain the skin’s hydrolipidic barrier, restoration of the skin’s natural antioxidant balance seems to be an alternative and convenient method to maintain healthy skin. At the moment, many studies have considered superoxide dismutase (SOD) as a good agent for the prevention or the therapeutic treatment of skin inflammation. Therefore, we will discuss the mechanism of action of SOD in numerous skin disorders and evaluate whether the use of a powerful antioxidant like SOD B can help deliver benefits against skin alterations.

Role of Antioxidant Enzymes, Hydrogen Peroxide and PRProteins in the Compatible and Incompatible Interactions of Cowpea (Vigna unguiculata) Genotypes with the Fungus Colletotrichum gloeosporioides

Role of Antioxidant Enzymes, Hydrogen Peroxide and PRProteins in the Compatible and Incompatible Interactions of Cowpea (Vigna unguiculata) Genotypes with the Fungus Colletotrichum gloeosporioides Several diseases, such as anthracnose, which are caused by the fungus species Colletotrichum gloeosporioides, negatively affect the cultivation of the cowpea (Vigna unguiculata). This work was conducted to measured the time-course activities and evaluate the possible roles of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and hydrogen peroxide (H2O2), and the pathogenesis-related proteins (PR-proteins), peroxidase (POX), β-1,3-glucanase (GLU) and chitinase (CHI), in the resistant (TE97) and susceptible (BR3) cowpea genotypes in response to C. gloeosporioides infection.

Changes in activities of SOD and GSH-Px in induced sputum and their significance among silicosis patients

To observe the changes in activities of superoxide dismutase (SOD) and glutathione peroxide (GSH-Px) in the induced sputum of silicosis patients, and to investigate the roles of SOD and GSH-Px in the development and progression of silicosis and the significance of measuring activities of SOD and GSH-Px in induced sputum among silicosis patients. Fifty hotel attendants were chosen as control group, 50 workers with more than one year of silica dust exposure as dust exposure group, 32 silica dust-exposed workers as observation subject group, and 52 silicosis patients as silicosis group. The activities of SOD and GSH-Px in their induced sputum were measured by enzyme-linked immunosorbent assay. Compared with the control group, the observation subject group and silicosis group had significantly decreased SOD activity (68.16 ± 30.17 and 66.38 ± 47.32 U/ml vs 75.81 ± 11.92 U/ml, P < 0.05); compared with the dust exposure group, the silicosis group had significantly decreased SOD activity (66.38 ± 47.32 U/ml vs 70.12 ± 14.31 U/ml, P < 0.05). Compared with the control group and dust exposure group, the observation subject group and silicosis group had significantly increased GSH-Px activity (268.21 ± 15.45 and 279.34 ± 29.26 U/ml vs 224.22 ± 12.64 and 236.41 ± 14.54 U/ml, P < 0.05 or P < 0.01). The SOD activity in dust exposure group and silicosis group decreased, but there were no significant differences between patients with different stages of silicosis. The GSH-Px activity in dust exposure group and silicosis group was significantly higher than that in control group, and there were significant differences between patients with different stages of silicosis. These suggest that the imbalance of oxidative/antioxidant systems is associated with the development and progression of silicosis.

Polymorphisms in the superoxidase dismutase genes reveal no association with human longevity in Germans: a case–control association study

The role of superoxide dismutases (SODs) in aging and oxidative stress regulation has been widely studied and there is growing evidence that imbalances in these processes influence lifespan in several species. In humans, genetic polymorphisms in SOD genes may play an important role in the development of age-related diseases and genetic variation in SOD2 is thought to be associated with longevity. These observations prompted us to perform a case-control association study using a comprehensive haplotype tagging approach for the three SOD genes (SOD1, SOD2, SOD3) by testing a total of 19 SNPs in our extensive collection of 1,612 long-lived individuals (centenarians and nonagenarians) and 1,104 younger controls. Furthermore, we intended to replicate the previous association of the SOD2 SNP rs4880 with longevity observed in a Danish cohort. In our study, no association was detected between the tested SNPs and the longevity phenotype, neither in the entire long-lived sample set nor in the centenarian subgroup analysis. Our results suggest that there is no considerable influence of sequence variation in the SOD genes on human longevity in Germans.

Early induction of Fe-SOD gene expression is involved in tolerance to Mn toxicity in perennial ryegrass

Manganese (Mn) toxicity limits plant growth in acid soils. Although Mn toxicity induces oxidative stress, the role of superoxide dismutase (SOD, EC.1.15.1.1) isoforms in conferring Mn tolerance remains unclear. Seedlings of ryegrass cultivars Nui (Mn-sensitive) and Kingston (Mn-tolerant) were hydroponically grown at 2.4 (optimal) or 750 μM Mn (toxic) concentration, and harvested from 2 to 48 h. Kingston showed higher shoot Mn than Nui at 2.4 μM Mn. At toxic supply, shoot Mn concentration steadily increased in both cultivars, with Kingston having the highest accumulation at 48 h. An early (2 h) increase in lipid peroxidation under Mn excess occurred, but it returned (after 6 h) to the basal level in Kingston only. Kingston exhibited higher SOD activity than Nui, and that difference increased due to toxic Mn. In general, Mn-induced gene expression of Mn- and Cu/Zn-SOD isoforms was higher in Nui than Kingston. Nevertheless, under Mn excess, we found a greater Fe-SOD up-regulation (up to 5-fold) in Kingston compared to Nui. Thus, Fe-SOD induction in Kingston might explain, at least partly, its high tolerance to Mn toxicity. This is the first evidence that Mn toxicity causes differential gene expression of SOD isoforms in ryegrass cultivars in the short-term.