Types Of Oxidative Stress Research Articles

Characterization of Transferrin‐1 from Drosophila melanogaster

Transferrins are secreted proteins that bind iron. Mammalian serum transferrin is involved in iron transport, while mammalian lactoferrin functions as an immune protein. Both proteins are thought to protect against oxidative stress. Insect transferrin is similar to both serum transferrin and lactoferrin, and its functions are not well characterized. Previous studies have demonstrated that insect transferrin can function as an immune protein, and limited data suggest that it may have a role in protection against oxidative stress and in iron transport. The goal of this study was to identify the functions of Drosophila melanogaster transferrin‐1 (DmTsf1). Our approach was to observe changes in DmTsf1 concentration in response to immune challenge, oxidative stress, metal stress, and dietary iron availability; test the antimicrobial activity of apo and holo forms of DmTsf1; and evaluate phenotypes associated with RNAi‐mediated knockdown of DmTsf1. We estimated the concentration of DmTsf1 in hemolymph to be 0.5 μM in larvae, 4 μM in adult females and 20 μM in adult males. We found that DmTsf1 concentration increased after inoculation of bacteria, and that DmTsf1 inhibited bacterial growth by sequestering iron. These findings indicate that DmTsf1 can protect flies against bacterial infection. In contrast to its response to immune challenge, DmTsf1 was not upregulated in response to paraquat‐induced oxidative stress, metal stress, or changes in dietary iron availability. We used genetic crosses to generate insects with strong or weak knockdown of DmTsf1 and observed that strong knockdown resulted in mortality in the early larval stages, while 75% knockdown resulted in insects that eclosed as normal‐looking adults. We found that knockdown of DmTsf1 had no effect on an insect's susceptibility to paraquat; therefore, DmTsf1 does not seem to protect flies from paraquat‐induced oxidative stress. Likewise, knockdown of DmTsf1 had no effect on the susceptibility of insects to a high iron diet. Additional experiments to test the effect of knockdown on susceptibility to iron‐induced oxidative stress are ongoing. Our findings demonstrate that DmTsf1 inhibits bacterial growth by iron sequestration, that it does not protect against at least some types of oxidative stress, and that it plays an essential but still unknown role in development.Support or Funding InformationNIH NGMS R37 GM041247, NSF IOS 1656388This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ophthalmic acid is a marker of oxidative stress in plants as in animals

BackgroundOphthalmic acid (OPH), γ-glutamyl-L-2-aminobutyryl-glycine, a tripeptide analogue of glutathione (GSH), has recently captured considerable attention as a biomarker of oxidative stress in animals. The OPH and GSH biosynthesis, as well as some biochemical behaviors, are very similar. Here, we sought to investigate the presence of OPH in plants and its possible relationship with GSH, known to possess multiple functions in the plant development, growth and response to environmental changes. MethodsHPLC-ESI-MS/MS analysis was used to examine the occurrence of OPH in leaves from various plant species, and flours from several plant seeds. Different types of oxidative stress, i.e., water, dark, paraquat, and cadmium stress, were induced in rye, barley, oat, and winter wheat leaves to evaluate the effects on the levels of OPH and its metabolic precursors. ResultsOPH and its dipeptide precursor, γ-glutamyl-2-aminobutyric acid, were found to occur in phylogenetically distant plants. Interestingly, the levels of OPH were tightly associated with the oxidative stress tested. Levels of OPH precursors, γ-glutamyl-2-aminobutyric acid and 2-aminobutyric acid, the latter efficiently formed in plants via biosynthetic pathways absent in the animal kingdom, were also found to increase during oxidative stress. ConclusionsOPH occurs in plants and its levels are tightly associated with oxidative stress. General significanceOPH behaves as an oxidative stress marker and its biogenesis might occur through a biochemical pathway common to many living organisms.

Nanoencapsulation strategies for the delivery of novel bifunctional antioxidant/σ1 selective ligands

Nowadays sigma-1 receptors are considered as new therapeutic objectives for central nervous system neurodegenerative diseases. Among different molecules, alpha lipoic acid has been identified as a natural potent antioxidant drug, whose therapeutic efficacy is limited by its many drawbacks, such as fast metabolism, poor bioavailability and high physico-chemical instability. Alfa-lipoic acid derivatives have been recently developed demonstrating their neuroprotective activity and effectiveness in different types of oxidative stress. In this work, two derivatives containing an amide or an ester functional group with different lipophilicity, were selected for their important affinity for sigma-1 receptors. Herein, in order to improve the in vitro stability and antioxidant effectiveness of alpha-lipoic acid derivatives, we focused our efforts in the nanoencapsulation strategies. Aqueous-core nanocapsules for the delivery of the hydrophilic compound and nanostructured lipid carrier for the lipophilic derivative, were properly designed and prepared using a direct or inverse eco-friendly organic solvent-free procedure. All nanosystems were characterized in terms of mean size, polydispersity, stability, morphology, encapsulation efficiency and in vitro release profiles. In order to evaluate the nanocarriers biocompatibility and antioxidant effectiveness, in vitro biological studies (cell viability, total antioxidant capacity and total oxidative status) were developed on primary human whole blood cell cultures, on both unloaded and derivatives-loaded nanodevices.

Relationships between Stress Granules, Oxidative Stress, and Neurodegenerative Diseases.

Cytoplasmic stress granules (SGs) are critical for facilitating stress responses and for preventing the accumulation of misfolded proteins. SGs, however, have been linked to the pathogenesis of neurodegenerative diseases, in part because SGs share many components with neuronal granules. Oxidative stress is one of the conditions that induce SG formation. SGs regulate redox levels, and SG formation in turn is differently regulated by various types of oxidative stress. These associations and other evidences suggest that SG formation contributes to the development of neurodegenerative diseases. In this paper, we review the regulation of SG formation/assembly and discuss the interactions between oxidative stress and SG formation. We then discuss the links between SGs and neurodegenerative diseases and the current therapeutic approaches for neurodegenerative diseases that target SGs.

The ROS Wheel: Refining ROS Transcriptional Footprints.

In the last decade, microarray studies have delivered extensive inventories of transcriptome-wide changes in messenger RNA levels provoked by various types of oxidative stress in Arabidopsis (Arabidopsis thaliana). Previous cross-study comparisons indicated how different types of reactive oxygen species (ROS) and their subcellular accumulation sites are able to reshape the transcriptome in specific manners. However, these analyses often employed simplistic statistical frameworks that are not compatible with large-scale analyses. Here, we reanalyzed a total of 79 Affymetrix ATH1 microarray studies of redox homeostasis perturbation experiments. To create hierarchy in such a high number of transcriptomic data sets, all transcriptional profiles were clustered on the overlap extent of their differentially expressed transcripts. Subsequently, meta-analysis determined a single magnitude of differential expression across studies and identified common transcriptional footprints per cluster. The resulting transcriptional footprints revealed the regulation of various metabolic pathways and gene families. The RESPIRATORY BURST OXIDASE HOMOLOG F-mediated respiratory burst had a major impact and was a converging point among several studies. Conversely, the timing of the oxidative stress response was a determining factor in shaping different transcriptome footprints. Our study emphasizes the need to interpret transcriptomic data sets in a systematic context, where initial, specific stress triggers can converge to common, aspecific transcriptional changes. We believe that these refined transcriptional footprints provide a valuable resource for assessing the involvement of ROS in biological processes in plants.

Plasma levels of oxidative stress-responsive apoptosis inducing protein (ORAIP) in rats subjected to physicochemical oxidative stresses.

Oxidative stress is known to play a pivotal role in the pathogenesis of various disorders including atherosclerosis, aging and especially ischaemia/reperfusion injury. It causes cell damage that leads to apoptosis. However, the precise mechanism has been uncertain. Recently, we identified an apoptosis-inducing humoral factor in a hypoxia/reoxygenated medium of cardiac myocytes. We named this novel post-translationally modified secreted form of eukaryotic translation initiation factor 5A (eIF5A) as oxidative stress-responsive apoptosis inducing protein (ORAIP). We developed a sandwich ELISA and confirmed that myocardial ischaemia/reperfusion markedly increased plasma levels of ORAIP. To investigate whether the role of ORAIP is common to various typesof oxidative stress, we measured plasma ORAIP levels in rats subjected to three physicochemical models of oxidative stress including N2/O2 inhalation, cold/warm-stress (heat shock) and blood acidification. In all three models, plasma ORAIP levels significantly increased and reached a peak level at 10-30min after stimulation, then decreased within 60min. The (mean±S.E.M.) plasma ORAIP levels before and after (peak) stimulation were (16.4±9.6) and (55.2±34.2) ng/ml in N2/O2 inhalation, (14.1±12.4) and (34.3±14.6) ng/ml in cold/warm-stress, and (18.9±14.3) and (134.0±67.2) ng/ml in blood acidification study. These data strongly suggest that secretion of ORAIP in response to oxidative stress is universal mechanism and plays an essential role. ORAIP will be an important novel biomarker as well as a specific therapeutic target of these oxidative stress-induced cell injuries.

Serum Heme Oxygenase-1 Level is Increased in Cardiac Patients with Elevated Serum Uric Acid and Decreased Renal Function

Heme oxygenase-1 (HO-1) is induced by various types of oxidative stress. We have investigated, among cardiac patients, whether serum HO-1 concentration was incresaed in patients with high serum uric acid (UA) and low renal function, conditions that are thought to be associated with increased oxidative stress. Serum HO-1 was measured using ELISA system. Serum HO-1 levels were found to be correlated with serum UA (R=0.61, P=0.017, Figure) and estimated GFR (eGFR) (R=0.55, P=0.026, by Spearman's test). On the other hand, serum HO-1 did not, although UA did, have significant association with left ventricular ejection fraction (Figure). Serum HO-1 level was elevated in patients with high UA and low eGFR. Circulating HO-1 may represent a useful biomarker for in vivo oxidative stress among cardiac patients.

붕장어와 식물류 추출 복합조성물의 투여가 유산소성 트레이드밀 운동에 의한 흰쥐의 피로회복 활성에 미치는 영향

붕장어와 식물류 혼합물(흑마늘, 흑삼, 흑대추)을 함께 추출함으로써 붕장어 특유의 비린내가 제거되어 맛과 향이 개선되고 피로회복 및 체력강화 기능성이 강화된 붕장어 복합조성물을 제조하였으며 그 활성을 검증하고자 흰쥐를 트레이드밀 운동 부하와 함께 5brix의 붕장어추출물(EE), 붕장어와 식물류 복합조성물 0.35 ml/100g/rat b.w. (EIM-1) 및 0.7 ml/100g/rat b.w. (EIM-2)를 투여하여 체내 지질 성분 및 항산화 효소 활성을 분석하였다. 식이효율은 정상군에 비해 EE군이 다소 낮았으나 대조군과 EIM-1 및 EIM-2군과는 유의차가 없었다. 간장의 지질함량은 정상군보다 실험군이 유의적으로 낮았고 EIM-1군이 가장 낮았다. 혈청 지질함량은 함량은 EMI-2군이 가장 낮았고 실험군은 정상군과 유의차가 없었다. 혈청 총콜레스테롤 함량은 정상군보다 실험군이 유의적으로 낮았는데 복합조성물을 투여한 EIM-2군이 가장 낮았다. HDL-콜레스테롤 함량은 트레이드밀 운동과 붕장어 및 붕장어 복합조성물을 투여함으로써 유의적으로 증가하여 정상군에 비해 EIM-1은 2.0배 및 EIM-2는 2.3배가 증가하였다. 간 글리코겐 함량은 운동을 실시한 실험군이 정상군에 비해 유의적으로 낮았으며 대조군에 비해 복합조성물을 투여한 군이 유의적으로 높았다. 간장 및 혈청의 TBARS 함량은 정상군에 비해 대조군에서 유의적으로 증가하였으나 EE군 및 EIM-1~2군은 대조군보다 낮았다. GOT 및 GPT 활성도 복합조성물을 급이함으로써 운동대조군에 비해 유의적으로 감소되었다. 붕장어 및 붕장어 복합조성물 투여에 따른 간조직에서 catalase 활성은 실험군간에 유의차가 없었으며 SOD 및 GSH-px 활성은 복합조성물 투여에 따라 대조군에 비해 유의적으로 증가하였다. 운동스트레스를 부과한 흰쥐에 붕장어와 복합조성물의 투여는 체내 콜레스테롤 함량 및 지질함량을 낮추고 항산화효소 활성을 증가시킴으로서 산화적 스트레스에 대한 생체 보호가 가능할 것으로 판단된다. The purpose of this study was to improve and strengthen the function of eel extract prepared with 5 brix eel extract (EE), 5 brix eel and plant mix (black garlic, ginseng, black jujube) 0.35 ml extracts prepared and treated with the extract (EIM-1), and 0.7 ml (EIM-2) divided group. The extracts were administered to rats for five weeks during running training, and the lipid profiles and antioxidant enzyme activities were tested. The lipid content in liver and serum were lower than the normal group difference was not significant between groups. Serum total cholesterol was lower in the experimental group than the control group the mixed extract significantly lower level. HDL-cholesterol levels in the eel extract and eel mixed extract significantly increased by feeding the EIM-1 is 2.0 times, EIM-2 is increased by 2.3 times. Liver glycogen content in the experimental group performed the exercise group compared with the normal control group was significantly lower than in EIM is significantly higher than the control group. The TBARS content in the liver and serum was significantly higher than the normal group was lower than the control group. GOT and GPT were significantly decreased compared to the control group. Hepatic catalase activity was significantly increased in the EIM-1 group, and SOD and GSH-px activities were increased in the EIM-1 and EIM-2 groups. Supplementation with the eel and plant mix extract increased the activities of antioxidant enzymes. Thus, intake of the eel and plant mix extract could improve the antioxidant status and combat different types of oxidative stress.

Intravitreal Inflammation: From Benchside to Bedside 2013

The aim of this special issue is to describe the role of inflammation in biological mechanisms of long-known diseases, providing an up-to-date viewpoint for therapeutic approaches. The authors provide a comprehensive overview, with original and review articles, on the implications of inflammation in proliferative vitreous retinopathy, on diabetic retinopathy, and on the potential iatrogenic damage induced by sustained intravitreal anti-VEGF therapy. Despite the copious literature, the exact mechanism of idiopathic epiretinal membranes formation (iERM) is still unclear. M. Joshi et al. showed the importance of glial cells and hyalocytes in its pathogenesis. Such cellular constituents of iERMs in concert with cytokines, growth factors (TGF and NGF), and anomalous posterior vitreous detachment are responsible for the prognosis and potential growth of epiretinal traction. The proliferative vitreoretinopathy (PVR) is recognized as a common secondary severe inflammatory complication of retinal detachment. C. Azzolini et al. reported two possible pathways (VEGF-A, Otx2, p53, p63, and Otx1 and Otx3) of PVR. These genetic pathways could represent a novel target of therapy of PVR progression. PVR is an even more common complication in patients with open-globe injury. F. Morescalchi et al. describe the role of immune cells into the vitreous gel in penetrating ocular injury. The cells stimulate the production of growth factors and cytokines, in particular PDGFR-α, which seem to be crucial in the development of PVR and, therefore, considered another potential therapeutic target. In a prospective, nonrandomized, observational study, C. Costagliola et al. showed that tear fluid collection is a useful and noninvasive method for the finding of proliferative diabetic retinopathy. The authors reported that TNF-alpha concentrations increase in tears according to the severity of proliferative and nonproliferative diabetic retinopathy. F. Parmeggiani et al. demonstrated the evidence of a relationship between AMD-risk genotypes, immunoinflammatory endophenotypes, and the networks of acquired or epigenetic factors. The authors reported that proinflammatory effects secondary to chronic inflammation and heterogeneous types of oxidative stress induce degenerative damage to the photoreceptors and outer retinal-blood barrier. In particular, the carriers of CFH, ARMS2/HRTA1, and C2/CFB genotypes demonstrated high odd ratio values. A score, calculating a risk including genetic findings, could be useful to identify individual risk, in order to provide preventive treatments. The intraviteral inflammation can be also secondary to iatrogenic treatment as intravitreal anti-VEGF therapy or vitreoretinal surgery. S. Agrawal et al. compared the sterile inflammation among the different intravitreal anti-VEGF drugs currently used for neovascular diseases. The acute intraocular inflammation is more frequently associated with bevacizumab likely due to the less strict purification procedure of the drug. In most cases, the inflammation solves spontaneously and vision returns to baseline. A history of previous inflammation does not increase the risk with following intravitreal injections. Previous vitreoretinal surgery can also induce intravitreal inflammation responsible for cytotoxic macular oedema. V. Romano et al. reported that intravitreal inflammation may increase after pars plana vitrectomy due to tractional phenomena at vitreomacular interfaces or due to a vasogenic damage. The oedema is characterized by fluid accumulation in the parenchymatous retinal cells (intracellular oedema) or by extracellular fluid accumulation due to a blood-retinal barrier damage (extracellular oedema). The treatment of vitreous inflammation is still a challenging issue; however, there are multiple methods of systemic treatment including T-cell inhibitors/calcineurin, antimetabolites, corticosteroids, alkylating agents, inhibitors, and biologic agents. A. Jiang et al. showed that these drugs can be used either alone or together in order to control vitreous inflammation due to variety of etiologies, either infectious or noninfectious. A. Russo et al. demonstrated that the topical nonsteroidal anti-inflammatory drugs (NSAIDs) allow for greater drug penetration into the vitreous. Topical NSAIDs reduce the exudation secondary to age-related macular degeneration or diabetic maculopathy. NSAIDs are also considered a favorable adjunct together with anti-VEGF that could potentially reduce the number of anti-VEGF injections. Finally, the chronicity of certain inflammatory conditions limits the efficacy of locally administered drugs. J. Wang et al. reported the last updates on implantable devices and particulate delivery systems such as nanoparticles, microparticles, and liposomes. These topics are actually considered the research focus of biomedical engineering, pharmacology, and molecular biology. We wish that this special issue will provide helpful information to recognize the clinical features of vitreous inflammation, to understand the mechanism beyond, and to identify the latest treatments in the disease in which the vitreous is involved. Mario R. Romano John Christoforidis

Differential gene expression in Giardia lamblia under oxidative stress: Significance in eukaryotic evolution

Giardia lamblia is a unicellular, early branching eukaryote causing giardiasis, one of the most common human enteric diseases. Giardia, a microaerophilic protozoan parasite has to build up mechanisms to protect themselves against oxidative stress within the human gut (oxygen concentration 60μM) to establish its pathogenesis. G. lamblia is devoid of the conventional mechanisms of the oxidative stress management system, including superoxide dismutase, catalase, peroxidase, and glutathione cycling, which are present in most eukaryotes. NADH oxidase is a major component of the electron transport chain of G. lamblia, which in concurrence with disulfide reductase, protects oxygen-labile proteins such as pyruvate: ferredoxin oxidoreductase against oxidative stress by sustaining a reduced intracellular environment. It also contains the arginine dihydrolase pathway, which occurs in a number of anaerobic prokaryotes, includes substrate level phosphorylation and adequately active to make a major contribution to ATP production.To study differential gene expression under three types of oxidative stress, a Giardia genomic DNA array was constructed and hybridized with labeled cDNA of cells with or without stress. The transcriptomic data has been analyzed and further validated using real time PCR. We identified that out of 9216 genes represented on the array, more than 200 genes encoded proteins with functions in metabolism, oxidative stress management, signaling, reproduction and cell division, programmed cell death and cytoskeleton. We recognized genes modulated by at least ≥2 fold at a significant time point in response to oxidative stress.The study has highlighted the genes that are differentially expressed during the three experimental conditions which regulate the stress management pathway differently to achieve redox homeostasis. Identification of some unique genes in oxidative stress regulation may help in new drug designing for this common enteric parasite prone to drug resistance. Additionally, these data suggest the major role of this early divergent ancient eukaryote in anaerobic to aerobic organism evolution.

Expression and cell distribution of neuroglobin in the brain tissue after experimental subarachnoid hemorrhage in rats: a pilot study.

Neuroglobin(Ngb) is a member of the globin superfamily expressed mainly in the nervous system andretina of vertebrates.Accumulated evidence has clearly demonstrated thatNgb has a neuro-protective role enhancing cell viability under hypoxia and other types of oxidative stress. It was suggested that oxidantstresscould play an important role in neuronal injury after subarachnoid hemorrhage (SAH).The present study aims to examine the expression of Ngb in the temporal cortex and its cellular localization after SAH. We used a prechiasmatic cistern model of SAH. Ngb expression was examined at 3, 6, 12, 24, 48, and 72h after SAH by western blot analysis and real-time polymerase chain reaction(PCR). Immunohistochemistry andimmunofluorescence were performed to detect the localization of Ngb. Real-time PCR demonstrated that Ngb mRNA levels increased from 3h after SAH, peaked at 6h. Western blot showed Ngb protein levels were significantly increased in SAH groups in the temporal cortex and reached the peak at 24h after SAH. The immunohistochemical staining demonstrated that Ngb was weakly expressed in the cortex in the control group while the enhanced expression of Ngb could be detected in the SAH groups. In addition,immunofluorescenceresults revealed that the over-expressed Ngb was located in the neuronal and microglia cell cytoplasm. These findings indicated that Ngb might play an important neuro-protective effect after SAH.

Retinoid X receptor activation is essential for docosahexaenoic acid protection of retina photoreceptors

We have established that docosahexaenoic acid (DHA), the major polyunsaturated fatty acid in the retina, promotes survival of rat retina photoreceptors during early development in vitro and upon oxidative stress by activating the ERK/MAPK signaling pathway. Here we have investigated whether DHA turns on this pathway through activation of retinoid X receptors (RXRs) or by inducing tyrosine kinase (Trk) receptor activation. We also evaluated whether DHA release from phospholipids was required for its protective effect. Addition of RXR antagonists (HX531, PA452) to rat retinal neuronal cultures inhibited DHA protection during early development in vitro and upon oxidative stress induced with Paraquat or H2O2. In contrast, the Trk inhibitor K252a did not affect DHA prevention of photoreceptor apoptosis. These results imply that activation of RXRs was required for DHA protection whereas Trk receptors were not involved in this protection. Pretreatment with 4-bromoenol lactone, a phospholipase A2 inhibitor, blocked DHA prevention of oxidative stress-induced apoptosis of photoreceptors. It is noteworthy that RXR agonists (HX630, PA024) also rescued photoreceptors from H2O2-induced apoptosis. These results provide the first evidence that activation of RXRs prevents photoreceptor apoptosis and suggest that DHA is first released from phospholipids and then activates RXRs to promote the survival of photoreceptors.

Multiple interaction partners for Cockayne syndrome proteins: Implications for genome and transcriptome maintenance

Cockayne syndrome (CS) is characterized by progressive multisystem degeneration and is classified as a segmental premature aging syndrome. The majority of CS cases are caused by defects in the CS complementation group B (CSB) protein and the rest are mainly caused by defects in the CS complementation group A (CSA) protein. Cells from CS patients are sensitive to UV light and a number of other DNA damaging agents including various types of oxidative stress. The cells also display transcription deficiencies, abnormal apoptotic response to DNA damage, and DNA repair deficiencies. Herein we have critically reviewed the current knowledge about known protein interactions of the CS proteins. The review focuses on the participation of the CSB and CSA proteins in many different protein interactions and complexes, and how these interactions inform us about pathways that are defective in the disease.

English

Introduction Halogenative and nitrosative stress are two types of oxidative stress that have been proposed as pathogenic mechanisms in Parkinson’s disease (PD). They can be caused by overstimulation of phagocytes. This hypothesis discusses serum protein halogenation and nitrosylation as traits of maintained overstimulation of blood phagocytes in sporadic Parkinson’s disease. Hypothesis I hypothesize that maintained phagocyte overstimulation leads to both halogenative and nitrosative stress in PD, which are present in the serum and cerebrospinal fluid of patients. These types of oxidative stress could modify proteins related to the pathogenesis of PD. Evaluation of hypothesis It has been detected that the presence of halogenative stress in the serum and, to a lesser extent, cerebrospinal fluid of Parkinsonian patients leads to excess of advanced oxidized protein products. On the other hand, nitrosative stress is also present in serum and cerebrospinal fluid of patients with early PD, characterized by the selective increase of 3-nitrotyrosine proteins other than nitroalbumin and free 3-nitrotyrosine. Nitrosylation stress accompanies modification of the sites of nitrosylation of αsynuclein in these patients, characterized by dominant nitrosylation of tyrosine 125/136 residues. Conclusion Since metabolism of advanced oxidized protein products and 3nitrotyrosine proteins has been associated with phagocytic overstimulation, this pathological alteration could play a pathogenic role in sporadic PD. Our observations also lead to the hypothesis that serum level of advanced oxidized protein products is a prognostic marker for PD duration, and these oxidized proteins could participate in neuroinflammation. Besides, the evaluation of nitrosative stress through enhanced levels of 3-nitrotyrosine proteins in serum and cerebrospinal fluid without changes in nitroalbumin, together with the profile of tyrosine nitrosylation of serum α-synuclein characterized by dominant nitrosylation of Tyr125/136, could serve for the diagnosis of sporadic PD. Nitroα-synuclein is a main component of Lewy bodies, hallmarks of the disease, and serum nitro-α-synuclein could represent a pathogenic factor in PD. Introduction Oxidative stress is defined as an imbalance between the production of reactive oxygen and nitrogen species (ROS/RNS) and antioxidant mechanisms, and it is considered as an important pathogenic mechanism in Parkinson’s disease (PD)1–4. Halogenation is a type of oxidative stress induced by phagocytic overstimulation, leading to excess of several molecules such as advanced oxidized protein products (AOPPs). These products originate as a result of the action of free radicals such as chloramines and hypochlorous acid (HOCl) on proteins, and they are augmented in several diseases5. This halogenative process could also modify free amines such as tyrosine, leading to the formation of free 3chlorotyrosine, as shown in Figure 1. Another type of oxidative stress is nitrosylation, where oxidative modifications of proteins are secondary to excess of nitric oxide. Nitrosylation of tyrosine leading to 3-nitrotyrosine proteins or free 3-nitrotyrosine is the most prominent change, and this type of oxidative stress has been associated with human pathologies6, and it is recognized as a salient feature of diverse α-synucleinopathies such as PD and Lewy body dementia7. In PD, protein tyrosine nitrosylation has been demonstrated to represent a pathogenic mechanism, and nitrosylated tyrosine residues of diverse proteins such as neurofilaments or α-synuclein are detected in the brain proteinaceous aggregates or Lewy bodies, hallmarks of the disease8. Moreover, nitrating agents generated by dopamine are known to promote α-synuclein aggregation9, a critical step for the formation of Lewy bodies. Biochemically, nitrosylated proteins and amines can be formed through different pathways (Figure 1). The formation of peroxynitrite (ONOO–) through nitric oxide and superoxide anion is the main pathway10. However, other nitrating pathways related to phagocyte overstimulation exist. For instance, myeloperoxidase (MPO) activity and nitric oxide excess from macrophages or brain microglia yield nitrosylated proteins and nitrotyrosines11. This hypothesis discusses if protein halogenation * Corresponding author Email: efespejo@us.es University of Seville, Department of Medical Physiology, Laboratory of Molecular Neurology and Neurophysiology, E-41009 Seville, Spain

The zinc finger protein ZAT11 modulates paraquat-induced programmed cell death in Arabidopsis thaliana

Plants use programmed cell death (PCD) as a tool in their growth and development. PCD is also involved in defense against different kinds of stresses including pathogen attack. In both types of PCD, reactive oxygen species (ROS) play an important role. ROS is not only a toxic by-product but also acts as signaling molecule that can trigger defense mechanisms in plant. Earlier transcriptome studies indicated the activation of ROS responsive and/or generating genes. Eight genes were selected with a potential role in ROS-induced PCD pathway and one of them, encoding the zinc finger protein ZAT11 (Zinc Arabidopsis thaliana11) exhibited an altered cell death phenotype. Two independent zat11 mutants in a loh2 (LAG one homologue2) genetic background showed enhanced tolerance to paraquat-induced oxidative stress and PCD; whereas, these double mutants exhibited cell death triggered by Alternaria alternata f. sp. lycopersici-toxin (AAL-toxin) or 3-aminotriazole (AT). This indicates that ZAT11 is involved in an intricate oxidative stress-induced PCD network, and the final outcome depends on ZAT11 interactions with other players specific for the particular types of oxidative stress.

The function of ORAOV1/LTO1, a gene that is overexpressed frequently in cancer: essential roles in the function and biogenesis of the ribosome

ORAOV1 (oral cancer overexpressed) is overexpressed in many solid tumours, making a key contribution to the development of cancer, but the cellular role of ORAOV1 is unknown. The yeast orthologue of this protein is encoded by the hitherto uncharacterized essential gene, YNL260c. Expression of ORAOV1 restores viability to yeast cells lacking YNL260c. Under nonpermissive conditions, our conditional mutants of YNL260c are defective in the maturation of the 60S ribosomal subunit, whereas maturation of the 40S subunit is unaffected. Also, initiation of translation is abrogated when YNL260c function is lost. YNL260c is indispensible for life in oxygen, but is nonessential under anaerobic conditions. Consequently, the toxic affects of aerobic metabolism on biogenesis and function of the ribosome are alleviated by YNL260c, hence, we rename YNL260c as LTO1; required for biogenesis of the large ribosomal subunit and initiation of translation in oxygen. Lto1 is found in a complex with Rli1/ABCE1, an ATP-binding cassette (ABC)-ATPase bearing N-terminal [4Fe-4S] clusters. Like Lto1, the Rli1/ABCE1 [4Fe-4S] clusters are not required for viability under anaerobic conditions, but are essential in the presence of oxygen. Loss of Lto1 function renders cells susceptible to hydroperoxide pro-oxidants, though this type of sensitivity is specific to certain types of oxidative stress as the lto1 mutants are not sensitive to an agent that oxidizes thiols. These findings reflect a functional interaction between Lto1 and the Rli1/ABCE1 [4Fe-4S] clusters, as part of a complex, which relieves the toxic effects of reactive oxygen species (ROS) on biogenesis and function of the ribosome. This complex also includes Yae1, which bridges the interaction between Lto1 and Rli1/ABCE1. Interactions between members of this complex were demonstrated both in vivo and in vitro. An increased generation of ROS is a feature shared by many cancers. The ORAOV1 complex could prevent ROS-induced ribosomal damage, explaining why overexpression of ORAOV1 is so common in solid tumours.

Serum from Parkinson’s disease patients presents excess of protein halogenation and nitrosylation, with anomalous nitrosylation of serum α-synuclein as potentially etiological factor

Background Halogenative and nitrosative stress are two types of oxidative stress that have been proposed as pathogenic mechanisms in Parkinson’s disease (PD). They can be caused by over-stimulation of phagocytes. We hypothesize that maintained phagocyte overstimulation leads to both halogenative and nitrosative stress in Parkinson’s disease, which are present in serum and cerebrospinal fluid of patients. These types of oxidative stress could modify proteins related to the pathogenesis of Parkinson’s disease.

Comparative genomics of neuroglobin reveals its early origins.

BackgroundNeuroglobin (Ngb) is a hexacoordinated globin expressed mainly in the central and peripheral nervous system of vertebrates. Although several hypotheses have been put forward regarding the role of neuroglobin, its definite function remains uncertain. Ngb appears to have a neuro-protective role enhancing cell viability under hypoxia and other types of oxidative stress. Ngb is phylogenetically ancient and has a substitution rate nearly four times lower than that of other vertebrate globins, e.g. hemoglobin. Despite its high sequence conservation among vertebrates Ngb seems to be elusive in invertebrates.Principal FindingsWe determined candidate orthologs in invertebrates and identified a globin of the placozoan Trichoplax adhaerens that is most likely orthologous to vertebrate Ngb and confirmed the orthologous relationship of the polymeric globin of the sea urchin Strongylocentrotus purpuratus to Ngb. The putative orthologous globin genes are located next to genes orthologous to vertebrate POMT2 similarly to localization of vertebrate Ngb. The shared syntenic position of the globins from Trichoplax, the sea urchin and of vertebrate Ngb strongly suggests that they are orthologous. A search for conserved transcription factor binding sites (TFBSs) in the promoter regions of the Ngb genes of different vertebrates via phylogenetic footprinting revealed several TFBSs, which may contribute to the specific expression of Ngb, whereas a comparative analysis with myoglobin revealed several common TFBSs, suggestive of regulatory mechanisms common to globin genes.SignificanceIdentification of the placozoan and echinoderm genes orthologous to vertebrate neuroglobin strongly supports the hypothesis of the early evolutionary origin of this globin, as it shows that neuroglobin was already present in the placozoan-bilaterian last common ancestor. Computational determination of the transcription factor binding sites repertoire provides on the one hand a set of transcriptional factors that are responsible for the specific expression of the Ngb genes and on the other hand a set of factors potentially controlling expression of a couple of different globin genes.

Disulfide stress as a novel type of oxidative stress in acute inflammation

Disulfide stress as a novel type of oxidative stress in acute inflammation

Hemostatic System in Wistar Rats in Different Types of Oxidative Stress

We studied parameters of hemostatic homeostasis in isolated and combined exposure to low-intensity γ-irradiation in a low dose, hyperbaric oxygenation, and antiorthostatic hypokinesia. Complex effects of the above stress factors are accompanied by a pronounced hypercoagulable shift with signs of thrombinemia against the background of depressed fibrinolysis, which indicates the risk of intravascular blood coagulation.