Extracellular Superoxide Dismutase Research Articles

Lung SOD3 limits neurovascular reperfusion injury and systemic immune activation following transient global cerebral ischemia

Background and ObjectivesStudies implicate the lung in moderating systemic immune activation via effects on circulating leukocytes. In this study, we investigated whether targeted expression of the antioxidant extracellular superoxide dismutase (SOD3) within the lung would influence post-ischemic peripheral neutrophil activation and CNS reperfusion injury. MethodsAdult, male mice expressing human SOD3 within type II pneumocytes were subjected to 15 min of transient global cerebral ischemia. Three days post-reperfusion, lung and brain tissue was collected and analyzed by immunohistochemistry for inflammation and injury markers. In vitro motility and neurotoxicity assays were conducted to ascertain the direct effects of hSOD3 on PMN activation. Results were compared against C57BL/6 age and sex-matched controls. ResultsRelative to wild-type controls, hSOD3 heterozygous mice exhibited a reduction in lung inflammation, blood-brain barrier damage, and post-ischemic neuronal injury within the hippocampus and cortex. PMNs harvested from hSOD3 mice were also resistant to LPS priming, slower-moving, and less toxic to primary neuronal cultures. ConclusionsConstitutive, focal expression of hSOD3 is neuroprotective in a model of global cerebral ischemia-reperfusion injury. The underlying mechanism of SOD3-dependent protection is attributable in part to effects on the activation state and toxic potential of circulating neutrophils. These results implicate lung-brain coupling as a determinant of cerebral ischemia-reperfusion injury and highlight post-stroke lung inflammation as a potential therapeutic target in acute ischemic cerebrovascular injuries.

Comparison of Thymulin Activity with Other Measures of Marginal Zinc Deficiency.

Activity of the immunoregulatory peptide thymulin reflects differences in zinc status. This study compared thymulin activity with four other zinc status measures in rats fed zinc at either 5 or 25ppm. Rats fed the lower zinc showed the following results compared with rats with adequate zinc intake: serum thymulin activity 61% lower, serum zinc 31% lower, serum extracellular superoxide dismutase 18% lower, serum 5'-nucleotidase activity 26% lower, and liver metallothionein 28% lower. Thus, thymulin activities showed more sensitivity to restricted zinc intake than did four other parameters.

Microarray analysis of human abdominal aortic aneurysm (AAA) detected altered gene expression profiles including H19

Abstract AAA is often a life-threatening disease with poorly understood pathogenesis. We examined gene expression profiles between AAA and normal aorta specimens by cDNA microarray analysis. AAA wall specimens from 5 patients with AAA and grossly normal aortic walls from 3 transplant donors were employed in this study. Total RNA was extracted from each specimen, RT into cDNA, and labeled with phosphorus α-32P. cDNA probes were then hybridized onto human cardiovascular microarray and analyzed by densitometry. Quantitative differences of some genes were further explored by SYBR green-mediated qRT-PCR analysis. Pairwise comparisons of both microarray and qRT-PCR results were made by Student t-test. Most of the 588 genes studied had similar expression among AAA specimens and control aortas, however, 25 genes were upregulated and 26 downregulated. Expression of MMP-9, TIMP3, collagen 1A1 (COL1A1), COL6A3, COL15A1, decorin, MCP 1, Apo E, Apo D, H19 and others was increased. Expression of COL4A4, biglycan, caveolin 3, galectin 1, LDL receptor-related protein 1, extracellular SOD 3, ANP receptor A precursor and others was decreased. Most qRT-PCR results agreed well with those from microarray analysis, with few exceptions. A number of genes that have been previously postulated to participate in AAA pathogenesis, have been upregulated or their expression has been altered. We also revealed some genes that have not been yet studied in human AAA. Of note, H19, one of the most highly up-regulated transcripts in two mouse aneurysm models, was also significantly upregulated in human AAA. These results indicate that many genes involved in different cellular functions might contribute to the pathogenesis of AAA. Supported in part by grant RO1 HL64340 from NIH.

Transcriptional Alteration of Gene Biomarkers in Hemocytes of Wild Ostrea edulis with Molecular Evidence of Infections with Bonamia spp. and/or Marteilia refringens Parasites.

The European flat Ostrea edulis is highly susceptible to intracellular parasitic infections, particularly bonamiosis and marteiliosis. The defensive response of oyster to both bonamiosis and marteiliosis is typically mediated by hemocytes, which play a pivotal role in immune system homeostasis. In the present study, we first used a DNA-based tool in order to rapidly and specifically detect the presence of parasites in oysters from natural banks in the middle Adriatic Sea. In a second step, we used qRT-PCR to analyze the mRNA levels of a set of genes (i.e., superoxide dismutase (SOD), glutathione S-transferase (GST), metallothionein (MT), heat shock protein (HSP) 70 and 90, inhibitor of apoptosis (IAP), fas ligand (FAS), galectin (GAL) and extracellular superoxide dismutase (Ec-SOD)) expressed by hemocytes of flat oysters infected by the parasites, present singularly or in combination, compared to hemocytes from non-infected specimens. The results indicate that the presence of parasite DNA may be associated to a general upregulation of host genes related to apoptosis, detoxification and oxidative stress protection, with the exception of Ec-SOD, whose trend to a downregulation might reflect a mechanism for parasite escape before internalization.

Sepsis Impairs Thyroid Hormone Signaling and Mitochondrial Function in the Mouse Diaphragm.

Background: Sepsis can cause the nonthyroidal illness syndrome (NTIS), resulting in perturbed thyroid hormone (TH) signaling and reduced thyroxine (T4) levels. TH is a major regulator of muscle function, via its influence on mitochondria. This study aimed at evaluating the relationship between TH signaling, mitochondrial function, and the antioxidant defense system in the diaphragms of septic mice. Methods: Male C57Bl/6 mice were divided into two groups: cecal ligation and puncture (CLP) and sham. Twenty-four hours after surgery, plasma, diaphragms, and livers were collected. TH metabolism and responses were analyzed by measuring messenger RNA (mRNA) expression of Dio1 in the liver, and Thra, Thrb, Dio2, Slc16a10, and Slc16a2 (encodes MCT 10 and 8), in the diaphragm. T4 plasma levels were measured by radioimmunoassay. Damage to diaphragm mitochondria was assessed by electron microscopy and real-time polymerase chain reaction (qPCR), and function with oxygraphy. The diaphragm antioxidative defense system was examined by qPCR, analyzing superoxide dismutase (SOD) 1 (Sod1), mitochondrial superoxide dismutase (SOD 2; Sod2), extracellular superoxide dismutase (SOD 3; Sod3), glutathione peroxidase 1 (Gpx1), and catalase (Cat) expression. The effect of TH replacement was tested by treating the mice with T4 and triiodothyronine (T3) (CLP+TH) after surgery. Results: CLP mice presented reduced total plasma T4 concentrations, downregulated Dio1, and upregulated Il1b mRNA expression in the liver. CLP mice also displayed downregulated Thra, Thrb, Slc16a10, and Slc16a2 expression in the diaphragm, suggesting that TH signaling was compromised. The expression of Ppargc1a (encoding PGC1a) was downregulated, which correlated with the decrease in the number of total mitochondria, increase in the percentage of injured mitochondria, downregulation of respiratory chain complex 2 and 3 mRNA expression, and reduced maximal respiration. In addition, septic animals presented a three-fold increase in Ucp3 and G6pdh expression; downregulated Sod3, Gpx1, and Cat expression; and upregulated Sod2 expression, potentially due to elevated reactive oxygen species levels. The mitochondrial number and the percentage of injured mitochondrial were similar between sham and CLP+TH mice. Conclusions: Sepsis induced responses consistent with NTIS, resulted in mitochondrial damage and functional impairment, and modulated the expression of key antioxidant enzymes in the diaphragm. Thus, impaired diaphragm function during sepsis seems to involve altered local TH signaling, mitochondrial dysfunction, and oxidative stress defense.

Systematic assessment of chlorine tolerance mechanism in a potent biofilm-forming marine bacterium Halomonas boliviensis

Bacterial colonization on submerged surfaces is a fundamental phenomenon associated with biofouling in the marine environment. To control such bio-growth, chlorination is the most commonly practiced strategy in maritime activities. Although chlorination is found to have wide-spectrum biocidal efficacy, it is unsuccessful against some microorganisms. Chlorine-resistant marine bacteria have attracted much attention as their existence enhances microfouling progression and could be a threat to industries that use seawater for cooling purposes. In this study, a chlorine-resistant bacterium that was isolated from the early-stage marine biofilm was in vitro investigated for biofilm-forming potential and chlorine tolerance. The bacterial isolate was identified phylogenetically as Halomonas boliviensis and its chlorine tolerance response was compared with a chlorine-sensitive bacterium (Pseudoalteromonas espejiana), which is taken as reference bacterium. Experiments on chlorine exposure revealed that H. boliviensis could mount an unusual response against chlorine and therefore even at long-term chlorine exposure (for 4–8 h) at 8 mg l−1 of residual chlorine concentration, elicited mere ≤ 1-fold reduction in the viable count. Chlorine-resistant mechanisms of H. boliviensis was ascertained by analyzing cellular morphology, cell membrane destruction, extracellular polymeric substances (EPS), aggregation ability and superoxide dismutase (SOD) pattern. In contrast to P. espejiana, over-production in biosynthesis of capsular EPS, induction in aggregation ability and increase in SOD level were observed and these could contribute to chlorine tolerance stratagem in H. boliviensis. Microscopic analyes revealed that both isolates form strong biofilms on various artificial surfaces. Scientific insight into such contrasting studies on marine bacteria is rather infrequent as well as important from environment perspective and would help in designing efficient antifouling strategy.

Molecular Pathways Involved in Aerobic Exercise Training Enhance Vascular Relaxation.

The beneficial effects of exercise training on the cardiovascular system are well known. Because our knowledge of exercise-induced vascular function is still limited, we aimed to uncover the molecular mechanisms conditioning the improved vascular relaxation in muscular arteries. Male Wistar-Kyoto rats with the same ability to run on a treadmill after maximal exercise tests were allocated to the following two groups: trained (Tr) (treadmill, 50%-60% of maximal capacity, 5 d·wk) and untrained (UnTr). After 13 wk, the femoral arteries were harvested and used for functional, structural, and molecular analyses. Acetylcholine (ACh)-induced relaxation and nitric oxide (NO) production were enhanced in arteries from Tr rats compared with UnTr rats. Tr arteries exhibited reduced microRNA (miRNA)-124a expression (whose target is caveolin-1), increased the density of caveolae aligned along the sarcolemma and reduced ACh-induced relaxation in the presence of methyl-β-cyclodextrin, which disrupts caveolae. Higher endothelial NO synthase (eNOS) expression with lower miRNA-155 expression and the posttranslational modification of eNOS (phosphorylation of stimulatory Ser1177 and dephosphorylation of inhibitory Thr495) by the PI3-kinase/Akt1/2/3 pathway also contributed to the higher NO production induced by exercise training. Furthermore, increased Cu/Zn- and extracellular-superoxide dismutase expression and enhanced effects of their pharmacological scavenger activity on the ACh-induced response were observed in Tr arteries. The results of the present study provide a molecular basis for exercise-induced NO bioavailability in healthy femoral arteries. Increased caveolae domain and eNOS expression/activity in Tr arteries are associated with downregulation of miRNA-124a and -155, as well as are involved with higher antioxidant defense, subsequently inducing a favorable endothelium-dependent milieu in Tr arteries.

Tumor Necrosis Factor‐α Activates Integrin Signaling in Vascular Smooth Muscle Cells via α5 Receptor

Tumor necrosis factor‐α (TNFα) signaling requires superoxide (O2•−) to be produced extracellularly by NADPH oxidase 1 (Nox1) in vascular smooth muscle cells (VSMCs). Extracellular superoxide dismutase (ecSOD) converts O2•− to hydrogen peroxide (H2O2). It binds to the cell surface by association with either heparin‐sulfate or fibulin‐5, an extracellular matrix protein that interacts with integrin receptors. We previously found that ecSOD knockdown (siRNA) impaired TNFα signal transduction as reflected by MAPK and NF‐κB activation. Targeting of ecSOD also inhibited TNFα‐dependent activation of focal adhesion kinase (FAK) which reflects integrin receptor activation. Here we investigated the mechanism by which TNFα activates integrin signaling in VSMC. We analyzed NF‐κB activation in the presence of selective blocking antibodies (Ab) for integrin receptor subtypes previously shown to be expressed in VSMCs including α4, α5, αv, β1, and β3. TNFα‐induced NF‐κB activation was not affected by blockade of integrin receptors α4, αv, β1, and β3. However blocking of α5 reduced TNFα‐induced NF‐κB activation (control IgG + TNFα 7.36 ± 0.7, anti‐α5 Ab + TNFα 4.78 ± 0.3 fold change, p < 0.05, n = 5). We next sought to determine if α5 integrin is associated with upstream steps of integrin signaling in VSMCs. FAK and integrin‐linked kinase (ILK) are downstream effectors of integrin receptor activation. After 10 min, TNFα induced phosphorylation of both FAK and Protein Kinase B (Akt) which was used as a surrogate for ILK activation. Blockade of α5 receptors decreased TNFα‐induced phosphorylation of both FAK and Akt. Thus, short term exposure of VSMCs to TNFα transactivates α5 integrins and subsequently FAK and ILK‐Akt. We speculate that ecSOD localizes TNFα‐induced H2O2 production to the vicinity of α5 integrins via physical association with fibulin‐5 and this redox environment affects activation of the receptor.

Muscle‐specific Nrf2 deficiency exacerbates cancer cachexia‐induced skeletal muscle atrophy

Skeletal muscle atrophy is a hallmark of several debilitating diseases such as cancer, thereby contributing to morbidity and mortality. Oxidative stress, which is caused by excessive production of reactive oxygen species and/or decreased antioxidant defense, plays an important role in skeletal muscle atrophy in cancer cachexia. Nuclear factor erythroid 2–related factor 2 (Nrf2) is a master regulator of antioxidant gene transcription. However, a potential role for Nrf2 in protection against muscle atrophy in cancer cachexia remains to be determined. To investigate this, C57BL/6 mice were given a subcutaneous injection in the left flank with 107 3LL lung cancer cells or PBS control. A grip strength test was performed at 25–27 days after 3LL injection using a grip strength meter. At 4 weeks after 3LL injection, soleus, plantaris, gastrocnemius, and extensor digitorum longus muscles were harvested to assess muscle weight and expression of select proteins. Muscle‐specific Nrf2 knockout (Nrf2mKO) and wild‐type littermates (WT) mice were also injected with 3LL cells and their skeletal muscles were harvested within the same time frame. Our results demonstrated that grip strength in 3LL injected C57BL/6 mice was significantly lower than in control mice. Gastrocnemius and extensor digitorum longus muscle weights in 3LL injected mice were significantly lower than control mice. Protein carbonylation, a surrogate of oxidative stress, was significantly increased in 3LL injected mice compared with control mice. Extracellular superoxide dismutase (EcSOD) protein expression was also increased in 3LL injected mice. Gastrocnemius and extensor digitorum longus muscle weight in 3LL injected Nrf2mKO mice were significantly lower than in 3LL injected WT mice. Loss of Nrf2 in skeletal muscle also blunted the 3LL injection‐induced increase in EcSOD protein expression. These findings indicate that endogenous muscle Nrf2 is a key protective molecule against atrophy likely by limiting the oxidative stress burden of cancer cachexia.Support or Funding InformationThis study was funded by Grant‐in‐Aid for Scientific Research (B) (15H03080) (18H03153) to Mitsuharu Okutsu.

The commonly‐used anthracycline chemotherapy drug Doxorubicin impairs vascular endothelial function via stimulation of mitochondrial superoxide

Doxorubicin (DOXO), a commonly used anthracycline chemotherapeutic agent, increases the risk of cardiovascular (CV) related morbidity and mortality. A key mechanism by which DOXO increases CV disease risk is by inducing endothelial dysfunction (impaired endothelium‐dependent dilation [EDD]) but: 1) the underlying mechanisms are unknown; 2) there are no established treatments for preventing these side effects.PurposeWe tested the hypotheses that: 1) DOXO impairs EDD via excess mitochondrial (mito) superoxide‐induced reductions in nitric oxide (NO) bioavailability; 2) these effects can be prevented with a mito‐targeted antioxidant.MethodsC57BL6 male mice (4mo of age) received one injection of either sham (PBS; n=4) or DOXO (10mg/ml; n=8). After 4 weeks, we assessed endothelial function (ex vivo carotid artery EDD to increasing doses of acetylcholine [ACh]) and potential underlying mechanisms: NO bioavailability (ACh dose response in the presence of the NO‐synthase inhibitor, L‐NAME); aortic total and mito‐specific superoxide production (electron paramagnetic resonance spectroscopy); aortic cytosolic, extracellular and mito isoforms of superoxide dismutase (SOD) (immunoblot); and the roles of excess total and mito‐specific superoxide in regulating EDD (ACh dose response in the presence of the SOD mimetic, TEMPOL, and the mito‐targeted antioxidant, MitoQ, respectively).ResultsMechanisms of ActionDOXO reduced maximal EDD by 41% (95±3 vs. 54±3 %; P=0.003). This reduction was mediated by a decrease in NO bioavailability, as EDD was not different between groups following incubation with L‐NAME. Vascular smooth muscle sensitivity to NO (dilatory response to sodium nitroprusside) was unaltered. DOXO increased aortic total superoxide production by 38% (5.3±0.7 to 7.3±0.5 amplitude units; P=0.003), without compensatory upregulation in aortic cytosolic or extracellular SOD. Reduced EDD with DOXO was mediated by excess superoxide production, as indicated by restoration of maximal EDD with TEMPOL (97±2%). DOXO increased aortic mito superoxide production by 50% (1.0±0.1 to 1.5±0.1 amplitude units; P=0.01) and induced a 60% reduction in aortic mito SOD (1.0±0.2 vs. 0.4±0.1 absorbance units; P=0.01). Reduced EDD with DOXO was mediated by increased mito superoxide production, as indicated by restoration of maximal EDD with MitoQ (91±8%).PreventionNext, we supplemented mice with MitoQ (250μM in drinking water; n=5) for 4 weeks following DOXO and showed that MitoQ prevented the reduction in EDD (97±1%, P=0.002 vs. DOXO alone) by preserving NO bioavailability via reduced mito superoxide (no added improvement with MitoQ incubation).ConclusionThese results suggest DOXO‐induced vascular endothelial dysfunction is mediated by excess mito superoxide‐induced reduction in NO bioavailability. Our results also demonstrate that MitoQ supplementation prevented DOXO‐induced endothelial dysfunction by suppressing mito superoxide and preserving NO bioavailability. Because MitoQ is available and safe for human use, there may be translational potential for reducing CV‐related morbidity and mortality in patients that have received DOXO chemotherapy.Support or Funding InformationNIH T32 DK007135‐44 (Z.S.C.)

Increased extracellular superoxide and MMP9 attenuated COMP stabilization of BMPR2 potentially participate in pulmonary hypertension development

The role of bone morphogenetic protein type 2 receptor (BMPR2) in the development of pulmonary hypertension was emphasized after identifying mutations of the gene encoding BMPR2 among patients with idiopathic pulmonary artery hypertension. Since then many studies were devoted to investigate restoring BMPR2 signaling as a therapeutic strategy. Also, roles for increased oxidant mechanisms have been identified in the lungs and right ventricle (RV) of several animal models of PH. However, it is unclear whether altered redox state plays a role in the regulation of the BMPR2 pathway in pulmonary vascular cells. Our current studies provide evidence for extracellular superoxide regulating BMPR2 expression via a Matrix Metallopeptidase 9 (MMP9)/cartilage oligomeric matrix protein (COMP) dependent pathway. Mice deficient of extracellular SOD (SOD3) show evidence of BMPR2 depletion both in the absence and presence of chronic hypoxia. Incubation of bovine pulmonary arteries under hypoxic conditions (1% O2 for 48h) increased MMP9 activity and expression which was associated with increased superoxide production and BMPR2 depletion. Moreover, adding exogenous superoxide dismutase (SOD) to the media inhibited MMP9 activation in response to acute hypoxia. In cultured human PASMC, 24 hours of hypoxia (1% O2) induced significant increase of MMP9 activity and reduced COMP expression. MMP9 contributes to COMP/BMPR2 depletion in chronic hypoxia based on MMP9 deficient mice showing a preserved expression of both COMP & BMPR2 in lung tissues. Moreover, MMP9 deficient mice exposed to chronic hypoxia or Sugen/hypoxia showed a marked reduction of the elevated RV systolic pressures and Fulton index measurements of right ventricular hypertrophy compared to wild type mice under the same experimental conditions. ECHO measurements of PAAT/ET ratio, which correlate inversely and linearly with mean pulmonary artery pressure, in hypoxia‐exposed MMP9 KO mice showed increased ratios compared to animals exposed to chronic hypoxia or Sugen/hypoxia. These data are consistent with depletion of MMP9 reducing the development of pulmonary hypertension. Thus, increased extracellular superoxide appears to promote pathological loop of MMP9 mediated depletion of COMP leading to destabilization of BMPR2 and loss of its pulmonary hypertensive protective actions.Support or Funding InformationSupported by NIH Grants HL115124 & HL129797

Xenogeneic transplantation of human WJ-MSCs rescues mice from acute radiation syndrome via Nrf-2-dependent regeneration of damaged tissues.

There is an unmet medical need for radiation countermeasures that can be deployed for treatment of exposed individuals during ionizing radiation (IR) accidents or terrorism. Wharton's jelly mesenchymal stem cells (WJ-MSCs) from human umbilical cord have been shown to avoid allorecognition and induce a tissue-regenerating microenvironment, which makes them an attractive candidate for mitigating IR injury. We found that WJ-MSCs protected mice from a lethal dose of IR even when transplanted up to 24hours after irradiation, and a combination of WJ-MSCs and antibiotic (tetracycline) could further expand the window of protection offered by WJ-MSCs. This combinatorial approach mitigated IR-induced damage to the hematopoietic and gastrointestinal system. WJ-MSCs increased the serum concentration of the cytoprotective cytokines granulocyte colony-stimulating factor (G-CSF) and IL-6 in mice. Knockdown of G-CSF and IL-6 in WJ-MSCs before injection to lethally irradiated mice or transplantation of WJ-MSCs to lethally irradiated Nrf-2 knockout mice significantly nullified the therapeutic protective efficacy. Hence, WJ-MSCs could be a potential cell-based therapy for individuals accidentally exposed to radiation.

Effects of hesperidin on the growth performance, antioxidant capacity, immune responses and disease resistance of red swamp crayfish (Procambarus clarkii)

We evaluated the effects of hesperidin on the nonspecific immunity, antioxidant capacity and growth performance of red swamp crayfish (Procambarus clarkii). A total of 900 healthy crayfish were randomly divided into six groups: the control group (fed the basal diet) and the HES25, HES50, HES75, HES100 and HES150 groups, which were fed the basal diet supplemented with 25, 50, 75, 100 and 150 mg kg−1 hesperidin, respectively. The feeding experiment lasted 8 weeks. The results indicated that compared with the control group, the crayfish groups supplemented with 50–150 mg kg−1 hesperidin had a decreased feed conversion ratio (FCR) and increased final body weight (FBW), specific growth rate (SGR) and weight gain (WG) (P < 0.05). The protein carbonyl content (PCC), reactive oxygen species (ROS) level and malondialdehyde (MDA) level in the hepatopancreas and hemocytes were significantly lower, while the total antioxidant capacity (T-AOC), glutathione peroxidase (GPx) activity, and superoxide dismutase (SOD) activity were significantly higher in the crayfish groups supplemented with 50–150 mg kg−1 hesperidin than in the control group. Supplementation with 50–150 mg kg−1 hesperidin significantly increased the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), lysozyme (LZM), and phenoloxidase (PO) compared with the control group (P < 0.05); upregulated the mRNA expression of cyclophilin A (CypA), extracellular copper-zinc superoxide dismutase (ecCuZnSOD), GPxs, crustin, astacidin, Toll3 and heat shock protein 70 (HSP70) (P < 0.05); and decreased crayfish mortality following white spot syndrome virus (WSSV) infection. These findings indicate that dietary hesperidin supplementation at an optimum dose of 50–150 mg kg−1 may effectively improve nonspecific immunity, antioxidant capacity and growth performance in crayfish.

Kidney failure, arterial hypertension and left ventricular hypertrophy in rats with loss of function mutation of SOD3

Chronic kidney disease (CKD) poses a considerable medical and public health challenge, and the Dahl/Salt Sensitive (Dahl/SS) strain is often used for CKD study. Extracellular superoxide dismutase (SOD3) is important for removing extracellular superoxide anions and is highly expressed in renal tissue. Using a novel rat strain with loss-of-function mutation of SOD3 created by replacing glutamate 124 of SOD3 with aspartic acid (SOD3E124D rat strain), we determined the effect of SOD3 on renal function and blood pressure in Dahl/SS rats. We find that SOD3E124D rats are phenotypically indistinguishable from wild type rats through 8 weeks of age, but develop profound CKD characterized by focal necrosis and fibrosis, glomerulosclerosis, massive proteinaceous cast accumulation with tubular dilatation, interstitial fibrosis with hypertension and renal failure by 21 weeks. The SOD3E124D strain represents a unique rat model that spontaneously develops CKD in an age-dependent fashion. The finding that loss of SOD3 causes CKD indicates that extracellular oxidative stress contributes to CKD and renal failure.

Extracellular Superoxide Dismutase Regulates Early Vascular Hyaluronan Remodeling in Hypoxic Pulmonary Hypertension

Chronic hypoxia leads to pathologic remodeling of the pulmonary vasculature and pulmonary hypertension (PH). The antioxidant enzyme extracellular superoxide dismutase (SOD3) protects against hypoxia-induced PH. Hyaluronan (HA), a ubiquitous glycosaminoglycan of the lung extracellular matrix, is rapidly recycled at sites of vessel injury and repair. We investigated the hypothesis that SOD3 preserves HA homeostasis by inhibiting oxidative and enzymatic hyaluronidase-mediated HA breakdown. In SOD3-deficient mice, hypoxia increased lung hyaluronidase expression and activity, hyaluronan fragmentation, and effacement of HA from the vessel wall of small pulmonary arteries. Hyaluronan fragmentation corresponded to hypoxic induction of the cell surface hyaluronidase-2 (Hyal2), which was localized in the vascular media. Human pulmonary artery smooth muscle cells (HPASMCs) demonstrated hypoxic induction of Hyal2 and SOD-suppressible hyaluronidase activity, congruent to our observations in vivo. Fragmentation of homeostatic high molecular weight HA promoted HPASMC proliferation in vitro, whereas pharmacologic inhibition of hyaluronidase activity prevented hypoxia- and oxidant-induced proliferation. Hypoxia initiates SOD3-dependent alterations in the structure and regulation of hyaluronan in the pulmonary vascular extracellular matrix. These changes occurred soon after hypoxia exposure, prior to appearance of PH, and may contribute to the early pathogenesis of this disease.

An atlas of genetic correlations between psychiatric disorders and human blood plasma proteome.

Psychiatric disorders are a group of complex psychological syndromes with high prevalence. Recent studies observed associations between altered plasma proteins and psychiatric disorders. This study aims to systematically explore the potential genetic relationships between five major psychiatric disorders and more than 3,000 plasma proteins. The genome-wide association study (GWAS) datasets of attention deficiency/hyperactive disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BD), schizophrenia (SCZ) and major depressive disorder (MDD) were driven from the Psychiatric GWAS Consortium. The GWAS datasets of 3,283 human plasma proteins were derived from recently published study, including 3,301 study subjects. Linkage disequilibrium score (LDSC) regression analysis were conducted to evaluate the genetic correlations between psychiatric disorders and each of the 3,283 plasma proteins. LDSC observed several genetic correlations between plasma proteins and psychiatric disorders, such as ADHD and lysosomal Pro-X carboxypeptidase (p value=0.015), ASD and extracellular superoxide dismutase (Cu-Zn; p value=0.023), BD and alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase 6 (p value=0.007), MDD and trefoil factor 1 (p value=0.011), and SCZ and insulin-like growth factor-binding protein 6 (p value=0.011). Additionally, we detected four common plasma proteins showing correlation evidence with both BD and SCZ, such as tumor necrosis factor receptor superfamily member 1B (p value=0.012 for BD, p value=0.011 for SCZ). This study provided an atlas of genetic correlations between psychiatric disorders and plasma proteome, providing novel clues for pathogenetic and biomarkers, therapeutic studies of psychiatric disorders.

Extracellular superoxide dismutase (SOD3) ALA40THR genetic polymorphism in correlation to Doppler flow indices in the Egyptian preeclamptic patients

<br><b>Background</b><br>Preeclampsia (PE) is a common pregnancy-specific complication, characterized by hypertension and significant proteinuria at or after 20 weeks of pregnancy; it affects ∼ 5–10% of pregnant women worldwide and remains the second leading cause of maternal and perinatal morbidity and mortality. Depletion of antioxidant enzymes such as superoxide dismutase (SOD) might be associated with the development of PE.<br><b>Objective</b><br>This study aimed to investigate the correlation of Ala40Thr polymorphism of SOD3 gene with the severity of PE and its correlation to fetal Doppler flow indices.<br><b>Materials and methods</b><br>The study was conducted in 250 pregnant women, divided into three groups: 130 controls, 60 mild PE cases, and 60 severe PE cases. They all underwent transabdominal ultrasound for assessment of resistance index and pulsatility index. The polymorphism was detected by PCR restriction fragment length polymorphism.<br><b>Results</b><br>There was a significant difference in the SOD3 Ala40Thr polymorphism between preeclamptic patients and controls, with higher risk of mutant GG variant compared with the wild-type AA in patients. The gestational age at delivery and pulsatility index were found to be significantly different among the three genotypes, with higher pulsatility index in severe cases compared with mild cases.<br><b>Conclusion</b><br>Follow-up of resistance index and pulsatility index with genotyping of SOD3 can give a clue for early prediction of PE avoiding preterm labor and intrauterine growth restriction.<br>

EVALUATION OF OX-LDL AND EXTRACELLULAR SUPEROXIDE DISMUTASE IN HEPATITIS C VIRUS PATIENTS BEFORE AND AFTER DIRECT-ACTING ANTIVIRAL THERAPY

Background: Hepatitis C virus (HCV) lifecycle is closely connected to host cell lipid metabolism, from cell entry, through viral RNA replication to viral particle production and formation/assembly. Objective: To determine the serum levels of ox-LDL, total antioxidant capacity and superoxide dismutase, and evaluate their role in HCV hepatitis patients. In addition, the effect of direct-acting antiviral therapy on their levels was evaluated. Patients and Methods: This study included forty chronic hepatitis C (genotype 4) patients. Blood samples were taken from the patients before and after taking sofosbuvir (400 mg) and daclatsvir 60 mg; one time daily orally for 24 weeks. Forty apparently healthy personnel were used as control group. Results: Serum TAC in chronic HCV hepatitis patients were significantly low before treatment as compared to the control group. Serum levels of ox-LDL were significantly high in patients before treatment and after treatment as compared to control group. Antioxidants supplementations and direct antiviral drugs did not affect the levels of ox-LDL significantly. Serum levels of extracellular SOD were significantly higher in control group, than levels in HCV patients before treatment and after treatment. Treatment did not restore the levels of serum SOD in patients. Direct-acting antiviral agents had a sustained virological response in the chosen group of patients. Conclusions: Direct-acting antiviral agents did not normalize serum levels of ox-LDL and extracellular SOD. In addition, the currently used antioxidants did not decrease the oxidative changes in LDL.

Aerobic Exercises Induce Antioxidant Pathways Activation in Rats.

Background:Aerobic exercises induce adaptations that improve physiological function. However, aerobic exercises, oxidative reproduction may lead to injury and other health issues such as adverse cardiac effects. The aim of this study is to evaluate the effect of aerobic exercises on protein expression change in the heart left ventricle to determine the advantages and disadvantages related to this mode of exercise.Methods:Male Wistar rats were randomized into two groups; trained (T) and control (C). Animals from T group were trained for 8 weeks, and then 2D LC-MS/MS iTRAQ method was used for extracting and analyzing the left ventricular proteins. Certain proteins that were highlighted in the special process were selected for further analysis via protein-protein interaction network (PPI) method. The identified proteins were enriched via gene ontology (GO) to find biological terms.Results:We identify five overexpressed antioxidant proteins in T group compared with C group including extracellular superoxide dismutase [Cu-Zn], Frataxin, protein kinase C delta type, STE20/SPS1-related proline-alanine-rich protein kinase, and amyloid-beta A4 protein.Conclusions:Findings indicate that catalase and insulin are two exercise-related proteins. However, they were not included in the significant differentially expressed proteins. Finally it was found that enhancement of antioxidative activity is a direct effect of aerobic exercises.

Copper-only superoxide dismutase enzymes and iron starvation stress in Candida fungal pathogens

Copper (Cu)-only superoxide dismutases (SOD) represent a newly characterized class of extracellular SODs important for virulence of several fungal pathogens. Previous studies of the Cu-only enzyme SOD5 from the opportunistic fungal pathogen Candida albicans have revealed that the active-site structure and Cu binding of SOD5 strongly deviate from those of Cu/Zn-SODs in its animal hosts, making Cu-only SODs a possible target for future antifungal drug design. C. albicans also expresses a Cu-only SOD4 that is highly similar in sequence to SOD5, but is poorly characterized. Here, we compared the biochemical, biophysical, and cell biological properties of C. albicans SOD4 and SOD5. Analyzing the recombinant proteins, we found that, similar to SOD5, Cu-only SOD4 can react with superoxide at rates approaching diffusion limits. Both SODs were monomeric and they exhibited similar binding affinities for their Cu cofactor. In C. albicans cultures, SOD4 and SOD5 were predominantly cell wall proteins. Despite these similarities, the SOD4 and SOD5 genes strongly differed in transcriptional regulation. SOD5 was predominantly induced during hyphal morphogenesis, together with a fungal burst in reactive oxygen species. Conversely, SOD4 expression was specifically up-regulated by iron (Fe) starvation and controlled by the Fe-responsive transcription factor SEF1. Interestingly, Candida tropicalis and the emerging fungal pathogen Candida auris contain a single SOD5-like SOD rather than a pair, and in both fungi, this SOD was induced by Fe starvation. This unexpected link between Fe homeostasis and extracellular Cu-SODs may help many fungi adapt to Fe-limited conditions of their hosts.