scholarly journals Infliximab Neutralizes the Suppressive Effect of TNF-α on Expression of Extracellular-Superoxide Dismutase in Vitro

2006 ◽  
Vol 29 (10) ◽  
pp. 2095-2098 ◽  
Author(s):  
Tetsuo Adachi ◽  
Taisuke Toishi ◽  
Eiji Takashima ◽  
Hirokazu Hara
Keyword(s):  
Superoxide Dismutase ◽  
Suppressive Effect ◽  
Tnf Alpha ◽  
Extracellular Superoxide Dismutase

scholarly journals RasOncogene-Mediated Progressive Silencing of Extracellular Superoxide Dismutase in Tumorigenesis

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Francesca Cammarota ◽  
Gabriella de Vita ◽  
Marco Salvatore ◽  
Mikko O. Laukkanen
Keyword(s):  
Superoxide Dismutase ◽  
Cancer Cells ◽  
Self Regulation ◽  
Thyroid Cell ◽  
Extracellular Superoxide Dismutase ◽  
Mrna Synthesis ◽  
Ras Activation ◽  
Degree Of Differentiation ◽  
In Cells

Extracellular superoxide dismutase (SOD3) is a secreted enzyme that uses superoxide anion as a substrate in a dismutase reaction that results in the formation of hydrogen peroxide. Both of these reactive oxygen species affect growth signaling in cells. Although SOD3 has growth-supporting characteristics, the expression ofSOD3is downregulated in epithelial cancer cells. In the current work, we studied the mechanisms regulatingSOD3expressionin vitrousing thyroid cell models representing different stages of thyroid cancer. We demonstrate that a low level of RAS activation increasesSOD3mRNA synthesis that then gradually decreases with increasing levels of RAS activation and the decreasing degree of differentiation of the cancer cells. Our data indicate thatSOD3regulation can be divided into two classes. The first class involves RAS–driven reversible regulation ofSOD3expression that can be mediated by the following mechanisms: RAS GTPase regulatory genes that are responsible forSOD3self-regulation; RAS-stimulated p38 MAPK activation; and RAS-activated increased expression of themir21microRNA, which inversely correlates withsod3mRNA expression. The second class involves permanent silencing ofSOD3mediated by epigenetic DNA methylation in cells that represent more advanced cancers. Therefore, the work suggests thatSOD3belongs to the group ofrasoncogene-silenced genes.

Plasma extracellular superoxide dismutase and erythrocyte Cu, Zn-containing superoxide dismutase in alcoholics treated with disulfiram

1986 ◽  
Vol 70 (4) ◽  
pp. 365-369 ◽  
Author(s):  
Michael Öhman ◽  
Stefan L. Marklund
Keyword(s):  
Superoxide Dismutase ◽  
Chronic Alcoholism ◽  
Term Treatment ◽  
Extracellular Superoxide Dismutase ◽  
Healthy Controls ◽  
Efficient Inhibitor ◽  
Long Term Treatment

1. Disulfiram has long been used in the treatment of chronic alcoholism. It is in vivo partially reduced to diethyldithiocarbamate, which is an efficient inhibitor of Cu, Zn-containing superoxide dismutase both in vitro and in vivo. The recently described extracellular superoxide dismutase is even more sensitive to diethyldithiocarbamate than Cu, Zn-superoxide dismutase. 2. To test for the possibility that long term treatment with disulfiram leads to inhibition of the superoxide dismutases, plasma extracellular superoxide dismutase and erythrocyte Cu, Zn-superoxide dismutase were determined in 12 disulfiram-treated alcoholics, and compared with 11 non-treated alcoholics and 19 healthy controls. 3. Plasma extracellular superoxide dismutase was moderately reduced (about 20%) in the disulfiram-treated alcoholics as compared with the non-treated alcoholics and the healthy controls. No effect of disulfiram treatment on erythrocyte Cu, Zn-superoxide dismutase activity was demonstrated.

scholarly journals Relationship of plasma extracellular-superoxide dismutase level with insulin resistance in type 2 diabetic patients

2004 ◽  
Vol 181 (3) ◽  
pp. 413-417 ◽  
Author(s):  
T Adachi ◽  
M Inoue ◽  
H Hara ◽  
E Maehata ◽  
S Suzuki
Keyword(s):  
Insulin Resistance ◽  
Superoxide Dismutase ◽  
Plasma Levels ◽  
Tnf Alpha ◽  
Diabetic Patients ◽  
Extracellular Superoxide Dismutase ◽  
Type 2 Diabetic Patients ◽  
Relationship Of ◽  
Type 2 Diabetic

Extracellular-superoxide dismutase (EC-SOD) is a secretory glycoprotein located in blood vessel walls at high levels and may be important in the antioxidant capability of vascular walls. The aim of this study was to assess plasma levels of EC-SOD and to evaluate the relationship of the EC-SOD level with insulin resistance in type 2 diabetic patients. We determined plasma EC-SOD in 122 patients and found for the first time that the EC-SOD level was strongly and positively related to adiponectin (r=0.503, P < 0.001), and significantly and inversely related to fasting plasma glucose (FPG) (r=-0.209, P=0.022), body-mass index (BMI) (r=-0.187, P=0.040) and homeostasis model assessment-insulin resistance index (HOMA-R) (r=-0.190, P=0.039). Stepwise-multiple regression analysis also showed a significant influence of adiponectin (F=33.27) on the EC-SOD level. Administration of pioglitazone to 19 diabetic patients significantly increased the plasma levels of EC-SOD (69.9+/-19.3 ng/ml to 97.4+/-25.9 ng/ml; P < 0.0001) and adiponectin, while it decreased tumor necrosis factor-alpha (TNF-alpha). The present observations suggest that factors related to the pathogenesis of insulin resistance play an important role in the regulation of the plasma EC-SOD concentration. It is possible that the increase in the EC-SOD level by pioglitazone administration in diabetic patients is due to a decline of TNF-alpha, which is known to suppress EC-SOD expression.

scholarly journals Extracellular Superoxide Dismutase (EC-SOD) Regulates Gene Methylation and Cardiac Fibrosis During Chronic Hypoxic Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Ayan Rajgarhia ◽  
Kameshwar R. Ayasolla ◽  
Nahla Zaghloul ◽  
Jorge M. Lopez Da Re ◽  
Edmund J. Miller ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Tissue Culture ◽  
Superoxide Dismutase ◽  
Cardiac Fibrosis ◽  
Extracellular Superoxide Dismutase ◽  
Hypoxic Stress ◽  
Fibroblast Proliferation ◽  
Gene Methylation ◽  
Hypoxic Group

Chronic hypoxic stress induces epigenetic modifications mainly DNA methylation in cardiac fibroblasts, inactivating tumor suppressor genes (RASSF1A) and activating kinases (ERK1/2) leading to fibroblast proliferation and cardiac fibrosis. The Ras/ERK signaling pathway is an intracellular signal transduction critically involved in fibroblast proliferation. RASSF1A functions through its effect on downstream ERK1/2. The antioxidant enzyme, extracellular superoxide dismutase (EC-SOD), decreases oxidative stress from chronic hypoxia, but its effects on these epigenetic changes have not been fully explored. To test our hypothesis, we used an in-vitro model: wild-type C57B6 male mice (WT) and transgenic males with an extra copy of human hEC-SOD (TG). The studied animals were housed in hypoxia (10% O2) for 21 days. The right ventricular tissue was studied for cardiac fibrosis markers using RT-PCR and Western blot analyses. Primary C57BL6 mouse cardiac fibroblast tissue culture was used to study the in-vitro model, the downstream effects of RASSF-1 expression and methylation, and its relation to ERK1/2. Our findings showed a significant increase in cardiac fibrosis markers: Collagen 1, alpha smooth muscle actin (ASMA), and SNAIL, in the WT hypoxic animals as compared to the TG hypoxic group (p &lt; 0.05). The expression of DNA methylation enzymes (DNMT 1&amp;3b) was significantly increased in the WT hypoxic mice as compared to the hypoxic TG mice (p &lt; 0.001). RASSF1A expression was significantly lower and ERK1/2 was significantly higher in hypoxia WT compared to the hypoxic TG group (p &lt; 0.05). Use of SiRNA to block RASSF1A gene expression in murine cardiac fibroblast tissue culture led to increased fibroblast proliferation (p &lt; 0.05). Methylation of the RASSF1A promoter region was significantly reduced in the TG hypoxic group compared to the WT hypoxic group (0.59 vs. 0.75, respectively). Based on our findings, we can speculate that EC-SOD significantly attenuates RASSF1A gene methylation and can alleviate cardiac fibrosis induced by hypoxia.

Mitochondrial superoxide dismutase induction does not protect epithelial cells during oxidant exposure in vitro

1995 ◽  
Vol 268 (1) ◽  
pp. L71-L77 ◽  
Author(s):  
V. L. Kinnula ◽  
P. Pietarinen ◽  
K. Aalto ◽  
I. Virtanen ◽  
K. O. Raivio
Keyword(s):  
Superoxide Dismutase ◽  
Epithelial Cells ◽  
Cell Injury ◽  
Oxidant Stress ◽  
Bronchial Epithelial Cells ◽  
Tnf Alpha ◽  
Ifn Gamma ◽  
Bronchial Epithelial ◽  
Mnsod Activity

The significance of manganese superoxide dismutase (MnSOD) induction in cells and tissues during oxidant stress is still poorly understood. In this study, transformed human bronchial epithelial cells (BEAS 2B) were treated with interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), or with combination of these cytokines (10 ng/ml concentrations) for 48 or 72 h and exposed to selected oxidants. TNF-alpha and IFN-gamma + TNF-alpha combination resulted in a marked increase of MnSOD protein and MnSOD activity. When cells pretreated with the cytokines were exposed to hyperoxia (95% O2, 72 h), menadione (5-50 microM, 4 h), or H2O2 (0.5 and 5 mM, 4 h), in all cases IFN-gamma and TNF-alpha enhanced oxidant-related cell injury. The effect was most significant with cells pretreated with a combination of IFN-gamma and TNF-alpha. Antioxidant enzymes such as total SOD, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase did not change significantly during the cytokine treatment. Catalase activity was not changed by IFN-gamma or TNF-alpha but it decreased significantly (34%) in IFN-gamma + TNF-alpha-treated cells. Free radical generation was not changed by these cytokines in acute (30 min) experimental conditions or after 48-h treatment. These results suggest that cytokine-induced MnSOD does not protect bronchial epithelial cells against endogenously or exogenously generated oxidants in vitro. In fact, cells that contained the highest MnSOD activity were the most sensitive to subsequent oxidant damage.

scholarly journals Non-enzymic glycation of human extracellular superoxide dismutase

1991 ◽  
Vol 279 (1) ◽  
pp. 263-267 ◽  
Author(s):  
T Adachi ◽  
H Ohta ◽  
K Hirano ◽  
K Hayashi ◽  
S L Marklund
Keyword(s):  
Superoxide Dismutase ◽  
Heparan Sulphate ◽  
Normal Subjects ◽  
Enzymic Activity ◽  
Diabetic Patients ◽  
Extracellular Superoxide Dismutase ◽  
Heparin Binding ◽  
A Minor ◽  
Heparin Affinity

The secretory enzyme extracellular superoxide dismutase (EC-SOD) is in plasma heterogenous with regard to heparin-affinity and can be divided into three fractions, A that lacks affinity, B with intermediate affinity and C with high affinity. The C fraction forms an equilibrium between the plasma phase and heparan sulphate proteoglycan on the surface of the endothelium. In vitro EC-SOD C could be time-dependently glycated. The enzymic activity was not affected in glycated EC-SOD, but the high heparin-affinity was lost in about half of the studied glycated fraction. Addition of heparin decreased the glycation in vitro, and EC-SOD C modified with the lysine-specific reagent trinitrobenzenesulphonic acid could not be glycated in vitro. The findings suggest that the glycation sites are localized rather far away from the active site and may occur on lysine residues in the heparin-binding domain in the C-terminal end of the enzyme. The proportion of glycated EC-SOD in serum of diabetic patients was considerably higher than in normal subjects. Of the subfractions, EC-SOD B was by far the most highly glycated, followed by EC-SOD A. EC-SOD C was glycated only to be a minor extent. The findings suggest that glycation is one of the factors that contribute to the heterogeneity in heparin-affinity of plasma EC-SOD. Since this phenomenon is increased in diabetes, the cell-surface-associated EC-SOD may be decreased in this disease, increasing the susceptibility of cells to superoxide radicals produced in the extracellular space.

The site of nonenzymic glycation of human extracellular-superoxide dismutase in vitro

1992 ◽  
Vol 13 (3) ◽  
pp. 205-210 ◽  
Author(s):  
T ADACHI ◽  
H OHTA ◽  
K HAYASHI ◽  
K HIRANO ◽  
S LMARKLUND
Keyword(s):  
Superoxide Dismutase ◽  
Extracellular Superoxide Dismutase
Sign in / Sign up

Export Citation Format

Share Document