Oxidative stress (OS) is considered a significant contributor to male infertility. A number of laboratory techniques have been developed to evaluate oxidative stress in the semen. We review these tests and their current use.

Atopic dermatitis is a common chronic/chronically relapsing inflammatory skin disease, with increasing worldwide prevalence. Etiopathogenesis is complex and multifactorial, with a mix of genetic, immunological and environmental aspects. Like in other chronic inflammatory diseases, oxidative stress plays an important pathogenetic role. We reviewed in vivo research studies on humans about oxidative stress and atopic dermatitis. Although sometimes contrasting, overall, they suggest that oxidative stress may have a significant role in atopic dermatitis, but our understanding is still incomplete, at least concerning in vivo data, because of limitations of available literature. Research consists of 33 papers published in 28 years, was not always performed on large study populations, represents a limited number of countries and ethnicities-not always in proportion to their size-and is scattered over multiple papers that, in the majority of cases, cannot be pooled and/or compared because many biomarkers were studied, in different tissues and with different methods. Further, larger studies appear warranted and necessary to shed more light on this aspect of atopic dermatitis, which is important not only to improve our understanding of this disease, but also for potential clinical and therapeutic implications.

Vascular tortuosity is associated with various disorders and is being increasingly detected through advances in imaging techniques. The underlying mechanisms for vascular tortuosity, however, remain unclear. Here, we tested the hypothesis that oxidative stress mediates the generation of tortuous vessels. We used the bilateral common carotid artery (CCA) ligation model to induce vascular tortuosity. Both young and adult rats showed basilar artery tortuous morphological changes one month after bilateral CCA ligation. These tortuous changes were permanent but more pronounced in the adult rats. Microarray and real-time PCR analysis revealed that these tortuous changes were accompanied by the induction of oxidative stress-related genes. Moreover, the indicated model in rabbits showed that tortuous morphological changes to the basilar artery were suppressed by antioxidant treatment. These results are highly suggestive of the significance of oxidative stress in the development of vascular tortuosity. Although further studies will be needed to elucidate the possible mechanisms by which oxidative stress enhances vascular tortuosity, our study also points toward possible prophylaxis and treatment for vascular tortuosity.

Prostatic diseases are a common health problem among males in Western countries, and include chronic prostatic diseases, which have an unclear pathogenesis and few treatment options. In vitro and in vivo studies describe oxidative stress as a major pathway involved in the occurrence of benign prostatic hyperplasia, prostatic cancer and chronic prostatitis. Thus, the oxidative stress cascade is a potential target for the treatment of prostatic diseases. This paper presents a systematic review of the available data concerning the association between oxidative stress and the most common chronic prostatic diseases, and describes the available treatment options that act upon this pathway.

The pathophysiologies of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), and Alzheimer's disease (AD), are far from being fully explained. Oxidative stress (OS) has been proposed as one factor that plays a potential role in the pathogenesis of neurodegenerative disorders. Clinical and preclinical studies indicate that neurodegenerative diseases are characterized by higher levels of OS biomarkers and by lower levels of antioxidant defense biomarkers in the brain and peripheral tissues. In this article, we review the current knowledge regarding the involvement of OS in neurodegenerative diseases, based on clinical trials and animal studies. In addition, we analyze the effects of the drug-induced modulation of oxidative balance, and we explore pharmacotherapeutic strategies for OS reduction.

Fibrosis is defined as increased fibroblast proliferation and deposition of extracellular matrix components with potential clinical ramifications including organ dysfunction and failure. Fibrosis is a characteristic finding of various skin diseases which can have life-threatening consequences. These implications call for research into this topic as only a few treatments targeting fibrosis are available. In this review, we discuss oxidative stress and its role in skin fibrosis. Recent studies have implicated the importance of oxidative stress in a variety of cellular pathways directly and indirectly involved in the pathogenesis of skin fibrosis. The cellular pathways by which oxidative stress affects specific fibrotic skin disorders are also reviewed. Finally, we also describe various therapeutic approaches specifically targeting oxidative stress to prevent skin fibrosis. We believe oxidative stress is a relevant target, and understanding the role of oxidative stress in skin fibrosis will enhance knowledge of fibrotic skin diseases and potentially produce targeted therapeutic options.

An increasing body of evidence suggests that alterations in neurogenesis and oxidative stress are associated with a wide variety of CNS diseases, including Alzheimer's disease, schizophrenia and Parkinson's disease, as well as routine loss of function accompanying aging. Interestingly, the association between neurogenesis and the production of reactive oxidative species (ROS) remains largely unexamined. The adult CNS harbors two regions of persistent lifelong neurogenesis: the subventricular zone and the dentate gyrus (DG). These regions contain populations of quiescent neural stem cells (NSCs) that generate mature progeny via rapidly-dividing progenitor cells. We hypothesized that the energetic demands of highly proliferative progenitors generates localized oxidative stress that contributes to ROS-mediated damage within the neuropoietic microenvironment. In vivo examination of germinal niches in adult rodents revealed increases in oxidized DNA and lipid markers, particularly in the subgranular zone (SGZ) of the dentate gyrus. To further pinpoint the cell types responsible for oxidative stress, we employed an in vitro cell culture model allowing for the synchronous terminal differentiation of primary hippocampal NSCs. Inducing differentiation in primary NSCs resulted in an immediate increase in total mitochondria number and overall ROS production, suggesting oxidative stress is generated during a transient window of elevated neurogenesis accompanying normal neurogenesis. To confirm these findings in vivo, we identified a set of oxidation-responsive genes, which respond to antioxidant administration and are significantly elevated in genetic- and exercise-induced model of hyperactive hippocampal neurogenesis. While no direct evidence exists coupling neurogenesis-associated stress to CNS disease, our data suggest that oxidative stress is produced as a result of routine adult neurogenesis.

Mitochondrial oxidative stress, mitochondrial dysfunction, or both have been implicated in insulin resistance. However, disentangling the individual roles of these processes in insulin resistance has been difficult because they often occur in tandem, and tools that selectively increase oxidant production without impairing mitochondrial respiration have been lacking. Using the dimer/monomer status of peroxiredoxin isoforms as an indicator of compartmental hydrogen peroxide burden, we provide evidence that oxidative stress is localized to mitochondria in insulin-resistant 3T3-L1 adipocytes and adipose tissue from mice. To dissociate oxidative stress from impaired oxidative phosphorylation and study whether mitochondrial oxidative stress per se can cause insulin resistance, we used mitochondria-targeted paraquat (MitoPQ) to generate superoxide within mitochondria without directly disrupting the respiratory chain. At ≤10 μm, MitoPQ specifically increased mitochondrial superoxide and hydrogen peroxide without altering mitochondrial respiration in intact cells. Under these conditions, MitoPQ impaired insulin-stimulated glucose uptake and glucose transporter 4 (GLUT4) translocation to the plasma membrane in both adipocytes and myotubes. MitoPQ recapitulated many features of insulin resistance found in other experimental models, including increased oxidants in mitochondria but not cytosol; a more profound effect on glucose transport than on other insulin-regulated processes, such as protein synthesis and lipolysis; an absence of overt defects in insulin signaling; and defective insulin- but not AMP-activated protein kinase (AMPK)-regulated GLUT4 translocation. We conclude that elevated mitochondrial oxidants rapidly impair insulin-regulated GLUT4 translocation and significantly contribute to insulin resistance and that MitoPQ is an ideal tool for studying the link between mitochondrial oxidative stress and regulated GLUT4 trafficking.

Oxidative stress is commonly involved in the pathogenesis of skin damage induced by environmental factors, such as heat stress. Skin fibroblasts are responsible for the connective tissue regeneration and the skin recovery from injury. Aloin, a bioactive compound in Aloe vera, has been reported to have various pharmacological activities, such as anti-inflammatory effects. The aim of this study was to investigate the protective effect of aloin against heat stress-mediated oxidative stress in human skin fibroblast Hs68 cells. Hs68 cells were first incubated at 43°C for 30 min to mimic heat stress. The study was further examined if aloin has any effect on heat stress-induced oxidative stress. We found that aloin protected Hs68 cells against heat stress-induced damage, as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assay. Aloin protected Hs68 cells by regulating reactive oxygen species production and increasing the levels of glutathione, cytosolic and mitochondrial superoxide dismutase. Aloin also prevented the elevation of thiobarbituric acid reactive substances and the reduction of 8-OH-dG induced by heat stress. These results indicated that aloin protected human skin fibroblasts from heat stress-induced oxidative stress damage by regulating the oxidative defense system.

The concept of oxidative stress (OS) that connects altered redox biology with various diseases was introduced 30 years ago and has generated intensive research over the past two decades. Whereas it is now commonly accepted that macromolecule oxidation in response to ROS is associated with a variety of pathologies, the emergence of NO as a key regulator of redox signalling has led to the discovery of the pathophysiological significance of reactive nitrogen species (RNS). RNS can elicit various modifications of macromolecules and lead to nitrative or nitro-OS. In order to investigate oxidative and nitro-OS in human and in live animal models, circulating biomarker assays have been developed. This article provides an overview of key biomarkers used to assess lipid peroxidation and NO/NO2 signalling, thereby stressing the necessity to analyse several OS biomarkers in relation to the overall (aerobic) metabolism and health condition of patients. In addition, the potential interest of heart rate variability as the non-invasive integrative biomarker of OS is discussed.

Extracellular vesicles (EVs) are increasingly studied as vectors for drug delivery because they can transfer a variety of molecules across biological barriers. SerpinB3 is a serine protease inhibitor that has shown a protective anti-apoptotic function in a variety of stressful conditions. The aim of this study was to evaluate protection from oxidative stress-induced damage, using extracellular vesicles that overexpress SerpinB3 (EVs-SB3) in order to enhance the effect of extracellular vesicles on cellular homeostasis. EVs-SB3s were obtained from HepG2 cells engineered to overexpress SerpinB3 and they revealed significant proteomic changes, mostly characterized by a reduced expression of other proteins compared with EVs from non-engineered cells. These EV preparations showed a significantly higher protection from H2O2 induced oxidative stress in both the hepatoma cell line and in primary cardiomyocytes, compared to cells treated with naïve EVs or SerpinB3 alone, used at the same concentration. In conclusion, the induction of SerpinB3 transgene expression results in the secretion of EVs enriched with the protein product that exhibits enhanced cytoprotective activity, compared with naïve EVs or the nude SerpinB3 protein.

Oxidative stress has been suggested to play a role in the pathogenesis of atrial fibrillation (AF). Indeed, the prevalence of AF increases with age as does oxidative stress. However, the mechanisms linking redox state to AF are not well understood. In this study we identify a link between oxidative stress and aberrant intracellular Ca(2+) release via the type 2 ryanodine receptor (RyR2) that promotes AF. We show that RyR2 are oxidized in the atria of patients with chronic AF compared with individuals in sinus rhythm. To dissect the molecular mechanism linking RyR2 oxidation to AF we used two murine models harboring RyR2 mutations that cause intracellular Ca(2+) leak. Mice with intracellular Ca(2+) leak exhibited increased atrial RyR2 oxidation, mitochondrial dysfunction, reactive oxygen species (ROS) production and AF susceptibility. Both genetic inhibition of mitochondrial ROS production and pharmacological treatment of RyR2 leakage prevented AF. Collectively, our results indicate that alterations of RyR2 and mitochondrial ROS generation form a vicious cycle in the development of AF. Targeting this previously unrecognized mechanism could be useful in developing effective interventions to prevent and treat AF.

Oxidative stress is frequently implicated in the pathology of neurodegenerative disease. The chief source of this stress is mitochondrial respiration, via the passage of reducing equivalents through the respiratory chain resulting in a small but potentially pathological production of superoxide. The superoxide that is produced during normal respiration is primarily detoxified within the mitochondria by superoxide dismutase 2 (Sod2), a key protein for maintaining mitochondrial function. Mitochondria are distributed throughout the soma of neurons, as well as along neuronal processes and at the synaptic terminus. This distribution of potentially independent mitochondria throughout the neuron, at distinct subcellular locations, allows for the possibility of regional subcellular deficits in mitochondrial function. There has been increasing interest in the quantification and characterization of messages and proteins at the synapse, because of its importance in neurodegenerative disease, most notably Alzheimer disease. Here, we report the transcriptomic and proteomic changes that occur in synaptosomes from frontal cortices of Sod2 null mice. Constitutively Sod2 null mice were differentially dosed with the synthetic catalytic antioxidant EUK-189, which can extend the life span of these mice, as well as uncovering or preventing neurodegeneration due to endogenous oxidative stress. This approach facilitated insight into the quantification of trafficked messages and proteins to the synaptosome. We used two complementary methods to investigate the nature of the synaptosome under oxidative stress: either whole-genome gene expression microarrays or mass spectrometry-based proteomics using isobaric tagging for relative and absolute quantitation of proteins. We characterized the relative enrichment of gene ontologies at both gene and protein expression levels that occurs from mitochondrial oxidative stress in the synaptosome, which may lead to new avenues of investigation in understanding the regulation of synaptic function in normal and diseased states. As a result of using these approaches, we report for the first time an activation of the mTOR pathway in synaptosomes isolated from Sod2 null mice, confirmed by an upregulation of the phosphorylation of 4E-BP1.

Primary Sjögren's syndrome (SjS) is a complex autoimmune epithelitis, with few treatment options, but the use of Janus kinase (JAK) inhibitors is promising because suppression of the JAK/signal transducer and activator of transcription (STAT) pathway improves sicca manifestations. Playing a primary and pathogenic role in disease development, the oxidative stress response is upregulated in activated salivary gland epithelial cells (SGECs) from patients with SjS. Therefore, the aim of this study was to investigate whether JAK inhibitors would suppress SGEC activation in response to an oxidative stress. For this purpose, the human salivary gland (HSG) cell line was used, and cells were treated with the reactive oxygen species (ROS) inducer hydrogen peroxide (H2O2) or with interferons (IFN Type I and Type II), used as positive controls, to mimic activated SGECs as observed in SjS patients. Afterward, the levels of the intracellular adhesion molecule-1 (ICAM-1) and the regulatory programmed-death ligand-1 (PD-L1) were measured by real-time PCR and flow cytometry, and the STAT1/3 phosphorylation status was assessed by Western blotting. Using the HSG cell line, our results showed that both ICAM-1 and PD-L1 are induced by ROS through pSTAT3, and that this activation pathway is reversed by the use of JAK inhibitors, AG490 and ruxolitinib, as well as by N-acetylcysteine, which is a direct inhibitor of ROS. These findings open new perspectives regarding the pathogenesis and therapeutic possibilities for SjS.

Oxidative stress and reactive oxygen species (ROS) are central to many physiological and pathophysiological processes. However, due to multiple technical challenges, it is hard to capture a comprehensive readout of the cell, involving both biochemical and functional status. We addressed this problem by developing a fully parallelized workflow for metabolomics (providing absolute quantities for > 100 metabolites including TCA cycle, pentose phosphate pathway, purine metabolism, glutathione metabolism, cysteine and methionine metabolism, glycolysis and gluconeogenesis) and live cell imaging microscopy. The correlative imaging strategy was applied to study morphological and metabolic adaptation of cancer cells upon short-term hydrogen peroxide (H2O2) exposure in vitro. The combination provided rich metabolic information at the endpoint of exposure together with imaging of mitochondrial effects. As a response, superoxide concentrations were elevated with a strong mitochondrial localization, and multi-parametric image analysis revealed a shift towards fragmentation. In line with this, metabolism reflected both the impaired mitochondrial function and shifts to support the first-line cellular defense and compensate for energy loss. The presented workflow combining high-end technologies demonstrates the applicability for the study of short-term oxidative stress, but it can be suitable for the in-depth study of various short-term oxidative and other cellular stress-related phenomena.

The prevalence of idiopathic male infertility is high, up to 75% of patients with abnormal sperm parameters. Hence, the research of its causes is mandatory. Oxidative stress (OS) can be responsible for male infertility in 30-80% of cases. In recent years, seminal plasma (SP) proteomics has developed as a useful tool to provide biomarkers of specific diseases. This systematic review aims to collect the available evidence on the changes of SP proteome in patients exposed to OS to provide possible SP biomarkers of sperm OS. To accomplish this, the following keyterms "seminal fluid proteome", "seminal plasma proteome", "oxidative stress", and "sperm oxidative stress" were used and 137 records were found. Among these, 17 were finally included. Nine proteins involved with OS were found overexpressed in patients with OS. Twenty-three proteins were found differentially expressed in patients with clinical conditions associated with OS, such as varicocele, male accessory gland infection/inflammation, cigarette smoke, and obesity. These proteins do not seem to overlap among the clinical conditions taken into account. We speculate that specific SP proteins may mediate OS in different clinical conditions. Altogether, these results suggest that proteomics could help to better understand some of the molecular mechanisms involved in the pathogenesis of infertility. However, further studies are needed to identify potential biomarkers of male infertility with valuable clinical significance.

Schizophrenia is associated with impaired antioxidant defense, including abnormal serum, plasma, and red blood cell (RBC) oxidative stress parameters. We performed a meta-analysis of these associations, considering the effect of clinical status and antipsychotic treatment after an acute exacerbation of psychosis.

Aging is a gradual, complex process in which cells, tissues, organs, and the whole organism itself deteriorate in a progressive and irreversible manner that, in the majority of cases, implies pathological conditions that affect the individual's Quality of Life (QOL). Although extensive research efforts in recent years have been made, the anticipation of aging and prophylactic or treatment strategies continue to experience major limitations. In this review, the focus is essentially on the compilation of the advances generated by cellular expression profile analysis through proteomics studies (two-dimensional [2D] electrophoresis and mass spectrometry [MS]), which are currently used as an integral approach to study the aging process. Additionally, the relevance of the oxidative stress factors is discussed. Emphasis is placed on postmitotic tissues, such as neuronal, muscular, and red blood cells, which appear to be those most frequently studied with respect to aging. Additionally, models for the study of aging are discussed in a number of organisms, such as Caenorhabditis elegans, senescence-accelerated probe-8 mice (SAMP8), naked mole-rat (Heterocephalus glaber), and the beagle canine. Proteomic studies in specific tissues and organisms have revealed the extensive involvement of reactive oxygen species (ROS) and oxidative stress in aging.

Glutathione oxidation and protein glutathionylation are considered hallmarks of oxidative stress in cells because they reflect thiol redox status in proteins. Our aims were to analyze the redox status of thiols and to identify mixed disulfides and targets of redox signaling in pancreas in experimental acute pancreatitis as a model of acute inflammation associated with glutathione depletion. Glutathione depletion in pancreas in acute pancreatitis is not associated with any increase in oxidized glutathione levels or protein glutathionylation. Cystine and homocystine levels as well as protein cysteinylation and γ-glutamyl cysteinylation markedly rose in pancreas after induction of pancreatitis. Protein cysteinylation was undetectable in pancreas under basal conditions. Targets of disulfide stress were identified by Western blotting, diagonal electrophoresis, and proteomic methods. Cysteinylated albumin was detected. Redox-sensitive PP2A and tyrosine protein phosphatase activities diminished in pancreatitis and this loss was abrogated by N-acetylcysteine. According to our findings, disulfide stress may be considered a specific type of oxidative stress in acute inflammation associated with protein cysteinylation and γ-glutamylcysteinylation and oxidation of the pair cysteine/cystine, but without glutathione oxidation or changes in protein glutathionylation. Two types of targets of disulfide stress were identified: redox buffers, such as ribonuclease inhibitor or albumin, and redox-signaling thiols, which include thioredoxin 1, APE1/Ref1, Keap1, tyrosine and serine/threonine phosphatases, and protein disulfide isomerase. These targets exhibit great relevance in DNA repair, cell proliferation, apoptosis, endoplasmic reticulum stress, and inflammatory response. Disulfide stress would be a specific mechanism of redox signaling independent of glutathione redox status involved in inflammation.

We evaluated the pharmacological effects of Myelophil, a 30% ethanol extract of a mix of Astragali Radix and Salviae Radix, on oxidative stress-induced brain damage in mice caused by restraint stress. C57BL/6 male mice (eight weeks old) underwent daily oral administration of distilled water, Myelophil (25, 50, or 100mg/kg), or ascorbic acid (100mg/kg) 1h before induction of restraint stress, which involved 3h of immobilization per day for 21days. Nitric oxide levels, lipid peroxidation, activities of antioxidant enzymes (superoxide dismutase, catalase, and glutathione redox system enzymes), and concentrations of adrenaline, corticosterone, and interferon-γ, were measured in brain tissues and/or sera. Restraint stress-induced increases in nitric oxide levels (serum and brain tissues) and lipid peroxidation (brain tissues) were significantly attenuated by Myelophil treatment. Restraint stress moderately lowered total antioxidant capacity, catalase activity, glutathione content, and the activities of glutathione reductase, glutathione peroxidase, and glutathione S-transferase; all these responses were reversed by Myelophil. Myelophil significantly attenuated the elevated serum concentrations of adrenaline and corticosterone and restored serum and brain interferon-γ levels. Moreover, Myelophil normalized expression of the genes encoding monoamine oxidase A, catechol-O-methyltransferase, and phenylethanolamine N-methyltransferase, which was up-regulated by restraint stress in brain tissues. These results suggest that Myelophil has pharmacological properties protects brain tissues against stress-associated oxidative stress damage, perhaps in part through regulation of stress hormones.