Oxidative damage to mitochondrial DNA and glutathione oxidation in apoptosis: studiesin vivoandin vitro

Free radicals may be involved in apoptosis although this is the subject of some controversy. Furthermore, the source of free radicals in apoptotic cells is not certain. The aim of this study was to elucidate the role of oxidative stress in the induction of apoptosis in serum-deprived fibroblast cultures and in weaned lactating mammary glands as in vitro and in vivo experimental models, respectively. Oxidative damage to mtDNA is higher in apoptotic cells than in controls. Oxidized glutathione (GSSG) levels in mitochondria from lactating mammary gland are also higher in apoptosis. There is a direct relationship between mtDNA damage and the GSSG/reduced glutathione (GSH) ratio. Furthermore, wh…

miRNA-23b as a biomarker of culture-positive neonatal sepsis

Abstract Background Neonatal sepsis remains an important cause of morbidity and mortality. The ability to quickly and accurately diagnose neonatal sepsis based on clinical assessments and laboratory blood tests remains difficult, where haemoculture is the gold standard for detecting bacterial sepsis in blood culture. It is also very difficult to study because neonatal samples are lacking. Methods Forty-eight newborns suspected of sepsis admitted to the Neonatology Department of the Mother-Child Specialized Hospital of Tlemcen. From each newborn, a minimum of 1–2 ml of blood was drawn by standard sterile procedures for blood culture. The miRNA-23b level in haemoculture was evaluated by RT-qP…

DNA binding, nuclease activity, DNA photocleavage and cytotoxic properties of Cu(II) complexes of N-substituted sulfonamides.

Abstract Ternary copper(II) complexes [Cu(NST)2(phen)] (1) and [Cu(NST)2(NH3)2]·H2O (2) [HNST = N-(4,5-dimethylthiazol-2-yl)naphthalene-1-sulfonamide] were prepared and characterized by physico-chemical techniques. Both 1 and 2 were structurally characterized by X-ray crystallography. The crystal structures show the presence of a distorted square planar CuN4 geometry in which the deprotonated sulfonamide, acting as monodentate ligand, binds to the metal ion through the thiazole N atom. Both complexes present intermolecular π–π stacking interactions between phenanthroline rings (compound 1) and between naphthalene rings (compound 2). The interaction of the complexes with CT DNA was studied b…

Selective regional distribution of tubulin induced in cerebrum by hyperammonemia

Ingestion of ammonium induces hyperammonemia which increases tubulin content in cerebrum but not in cerebellum. We have dissected 11 discrete areas of cerebrum and quantified the tubulin content in control and hyperammonemic rats. An heterogeneity in the induction of tubulin is shown. The areas more affected are ventral hippocampus, dorsal hippocampus, hypothalamus, septum, reticular formation and frontal cortex, in which tubulin content increased by 63%, 27%, 32%, 48%, 45%, and 25%, respectively, after two months of feeding the ammonium diet.

Oxidative stress-mediated alterations in histone post-translational modifications

Abstract Epigenetic regulation of gene expression provides a finely tuned response capacity for cells when undergoing environmental changes. However, in the context of human physiology or disease, any cellular imbalance that modulates homeostasis has the potential to trigger molecular changes that result either in physiological adaptation to a new situation or pathological conditions. These effects are partly due to alterations in the functionality of epigenetic regulators, which cause long-term and often heritable changes in cell lineages. As such, free radicals resulting from unbalanced/extended oxidative stress have been proved to act as modulators of epigenetic agents, resulting in alte…

Circulating Histones and Nucleosomes as Biomarkers in Sepsis and Septic Shock

Sepsis, severe sepsis, and septic shock are among the leading causes of death worldwide and their incidence is constantly increasing. Despite early intervention in intensive care units (ICUs) mortality remains high. There is great interest in understanding the genetics and epigenetics of the host in response to infection because of two reasons: the peculiarities of each patient, and the unclear associations identified between genetic polymorphisms and susceptibility to sepsis. In addition, chromatin remodeling and epigenetic changes occur in crucial genes involved in the inflammatory response and also in the immunosuppression found in sepsis. The early and accurate diagnosis of sepsis is a …

Extracellular histones trigger oxidative stress-dependent induction of the NF-kB/CAM pathway via TLR4 in endothelial cells.

Abstract Extracellular histones have been reported to aggravate different pathophysiological processes by increasing vascular permeability, coagulopathy, and inflammation. In the present study, we elucidate how extracellular histones (10–100 µg/mL) concentration dependently increase cytosolic reactive oxygen species (ROS) production using human umbilical vein endothelial cells (HUVECs). Furthermore, we identify cyclooxygenase (COX) and NADPH oxidase (NOX) activity as sources of ROS production in extracellular histone-treated HUVEC. This COX/NOX-mediated ROS production is also involved in enhanced NF-kB activity and cell adhesion molecules (VCAM1 and ICAM1) expression in histone-treated HUVE…

Role of glutathione in cell nucleus

Cells with high proliferation rate have high glutathione levels. This typical feature of cancer cells is viewed usually as a defence mechanism against ionizing radiation or chemotherapy. Efforts have been made in order to decrease cellular glutathione levels in tumours as a necessary pre-treatment for cancer therapy. However, very few reports have considered cellular glutathione as a physiological tool for cells to proliferate and that most of this high glutathione levels were located in the nucleus. The role of nuclear glutathione in cell physiology has become more important in the last years. This review summarizes new findings that point to the nuclear reduced status as an environment th…

Histone carbonylation occurs in proliferating cells

12 páginas, 10 figuras (que no es encuentran en este documento, se pueden ver en: http://www.sciencedirect.com/science/article/pii/S0891584912000664)

Acute telomerase components depletion triggers oxidative stress as an early event previous to telomeric shortening

Loss of function of dyskerin (DKC1), NOP10 and TIN2 are responsible for different inheritance patterns of Dyskeratosis congenita (DC; ORPHA1775). They are key components of telomerase (DKC1 and NOP10) and shelterin (TIN2), and play an important role in telomere homeostasis. They participate in several fundamental cellular processes by contributing to Dyskeratosis congenita through mechanisms that are not fully understood. Presence of oxidative stress was postulated to result from telomerase ablation. However, the resulting disturbed redox status can promote telomere attrition by generating a vicious circle, which promotes cellular senescence. This fact prompted us to study if acute loss of …

Mitochondria from females exhibit higher antioxidant gene expression and lower oxidative damage than males

We have investigated the differential mitochondrial oxidative stress between males and females to understand the molecular mechanisms enabling females to live longer than males. Mitochondria are a major source of free radicals in cells. Those from female rats generate half the amount of peroxides than those of males. This does not occur in ovariectomized animals. Estrogen replacement therapy prevents the effect of ovariectomy. Mitochondria from females have higher levels of reduced glutathione than those from males. Those from ovariectomized rats have similar levels to males, and estrogen therapy prevents the fall in glutathione levels that occurs in ovariectomized animals. Oxidative damage…

Ursodeoxycholic acid protects against secondary biliary cirrhosis in rats by preventing mitochondrial oxidative stress

Ursodeoxycholic acid (UDCA) improves clinical and biochemical indices in primary biliary cirrhosis and prolongs survival free of liver transplantation. Recently, it was suggested that the cytoprotective mechanisms of UDCA may be mediated by protection against oxidative stress, which is involved in the development of cirrhosis induced by chronic cholestasis. The aims of the current study were 1) to identify the mechanisms involved in glutathione depletion, oxidative stress, and mitochondrial impairment during biliary cirrhosis induced by chronic cholestasis in rats; and 2) to determine the mechanisms associated with the protective effects of UDCA against secondary biliary cirrhosis. The find…

A Drosophila model of GDAP1 function reveals the involvement of insulin signalling in the mitochondria-dependent neuromuscular degeneration

[EN] Charcot-Marie-Tooth disease is a rare peripheral neuropathy for which there is no specific treatment. Some forms of Charcot-Marie-Tooth are due to mutations in the GDAP1 gene. A striking feature of mutations in GDAP1 is that they have a variable clinical manifestation, according to disease onset and progression, histology and mode of inheritance. Studies in cellular and animal models have revealed a role of GDAP1 in mitochondrial morphology and distribution, calcium homeostasis and oxidative stress. To get a better understanding of the disease mechanism we have generated models of over-expression and RNA interference of the Drosophila Gdapl gene. In order to get an overview about the c…

Oxidative Stress, a Crossroad Between Rare Diseases and Neurodegeneration

Oxidative stress is an imbalance between production and accumulation of oxygen reactive species and/or reactive nitrogen species in cells and tissues, and the capacity of detoxifying these products, using enzymatic and non-enzymatic components, such as glutathione. Oxidative stress plays roles in several pathological processes in the nervous system, such as neurotoxicity, neuroinflammation, ischemic stroke, and neurodegeneration. The concepts of oxidative stress and rare diseases were formulated in the eighties, and since then, the link between them has not stopped growing. The present review aims to expand knowledge in the pathological processes associated with oxidative stress underlying …

Comparative Analysis of Chromatin-Delivered Biomarkers in the Monitoring of Sepsis and Septic Shock: A Pilot Study

Sepsis management remains one of the most important challenges in modern clinical practice. Rapid progression from sepsis to septic shock is practically unpredictable, hence the critical need for sepsis biomarkers that can help clinicians in the management of patients to reduce the probability of a fatal outcome. Circulating nucleoproteins released during the inflammatory response to infection, including neutrophil extracellular traps, nucleosomes, and histones, and nuclear proteins like HMGB1, have been proposed as markers of disease progression since they are related to inflammation, oxidative stress, endothelial damage, and impairment of the coagulation response, among other pathological…

Evaluation of the quality of publications on randomized clinical trials using the Consolidated Standards of Reporting Trials (CONSORT) statement guidelines in a Spanish tertiary hospital.

The main reason for conducting a clinical trial (CT) is to test the effect of a drug or medical procedure to improve treatment of a disease. CTs contribute most when they are rigorously conducted and the results are published adequately. The aim of this study is to assess, using the CONSORT statement guidelines, the quality of reporting of completed CTs conducted at a tertiary hospital to determine which sections of the articles should be improved. CTs published between 2002 and 2008 were identified by searching the MEDLINE and Cochrane Library. Forty of 127 completed CTs were published. There was a marked increase in the number of articles and the quality of the journals that published the…

Causes and Consequences of Damage to Mitochondria: Study of Functional Aspects by Flow Cytometry

A rapidly increasing amount of data supports the view that progressive bioenergetic loss caused by injury of the main energy-producing subcellular organelles, that is, the mitochondria, plays a key role in aging. A link between senescence and energy loss is already implied in Harman's (1) free radical theory of aging, according to which oxygen-derived free radicals injure the cells, with concomitant impairment of performance at the cellular and physiological levels. Further, Miquel and co-workers (2, 3) have proposed a mitochondrial theory of aging, according to which aging results from oxygen stress damage to the mitochondrial genome, with concomitant bioenergetic decline. More recently, a…

Exhaustive physical exercise causes oxidation of glutathione status in blood: Prevention by antioxidant administration

We have studied the effect of exhaustive concentric physical exercise on glutathione redox status and the possible relationship between blood glutathione oxidation and blood lactate and pyruvate levels. Levels of oxidized glutathione (GSSG) in blood increase after exhaustive concentric physical exercise in trained humans. GSSG levels were 72% higher immediately after exercise than at rest. They returned to normal values 1 h after exercise. Blood reduced glutathione (GSH) levels did not change significantly after the exercise. We have found a linear relationship between GSSG-to-GSH and lactate-to-pyruvate ratios in human blood before, during, and after exhaustive exercise. In rats, physical…

Dependence of hepatic gluconeogenesis on PO2: inhibitory effects of halothane

The dependence of gluconeogenesis and O2 uptake on PO2 in isolated rat hepatocytes is presented. Maintenance of steady-state PO2 was achieved with an oxystat system (Biochem. J. 236: 765–769, 1986). O2 uptake showed a half-maximal (K0.5) value of 0.5 Torr PO2, whereas the glucose synthesis rate was half-maximal at 1.2 Torr PO2. Halothane at concentrations greater than 1 mM exerted a parallel inhibition of O2 uptake and glucose synthesis at all PO2 levels studied. In contrast, at halothane concentrations less than 1 mM, inhibition of glucose synthesis occurred only at less than 20 Torr PO2. At these low concentrations, halothane was without significant effects on cellular O2 uptake. In isol…

Oral glutathione increases hepatic glutathione and prevents acetaminophen toxicity

Administration of oral glutathione (GSH) increases hepatic GSH levels in fasted rats, in mice treated with GSH depletors such as diethylmaleate and in mice treated with high doses of paracetamol. An increase in hepatic GSH levels after administration of oral GSH does not occur in animals treated with buthionine suphoximine, an inhibitor of GSH synthesis. Administration of oral GSH leads to an increase in the concentration of L-cysteine, a precursor of GSH, in portal blood plasma. Oral administration of L-methio-nine to fasted rats produced a significant decrease of hepatic ATP, but not in fed rats. Administration of N-acetyl-cysteine or GSH did not affect the hepatic ATP levels. The results…

17β-oestradiol up-regulates longevity-related, antioxidant enzyme expression via the ERK1 and ERK2[MAPK]/NFκB cascade

Females live longer than males. Oestrogens protect females against aging by up-regulating the expression of antioxidant, longevity-related genes such as glutathione peroxidase (GPx) and Mn-superoxide dismutase (Mn-SOD). The mechanism through which oestrogens up-regulate those enzymes remains unidentified, but may have implications for gender differences in lifespan. We show that physiological concentrations of oestradiol act through oestrogen receptors to reduce peroxide levels in MCF-7 cells (a mammary gland tumour cell line). Oestradiol increases MAP kinase (MAPK) activation as indicated by ERK1 and ERK2 phosphorylation in MCF-7 cells, which in turn activates the nuclear factor kappa B (N…

Oxygen in the neonatal period: Oxidative stress, oxygen load and epigenetic changes

Preterm infants frequently require positive pressure ventilation and oxygen supplementation in the first minutes after birth. It has been shown that the amount of oxygen provided during stabilization, the oxygen load, if excessive may cause hyperoxia, and oxidative damage to DNA. Epidemiologic studies have associated supplementation with pure oxygen in the first minutes after birth with childhood cancer. Recent studies have shown that the amount of oxygen supplemented to preterm infants after birth modifies the epigenome. Of note, the degree of DNA hyper-or hypomethylation correlates with the oxygen load provided upon stabilization. If these epigenetic modifications would persist, oxygen su…

Estradiol or genistein prevent Alzheimer's disease-associated inflammation correlating with an increase PPAR gamma expression in cultured astrocytes.

Inflammation has been implicated in neurodegenerative disorders such as Alzheimer's disease (AD). The main inflammatory players in AD are the glial cells which initiate the inflammatory response. One of the earliest neuropathological changes in AD is the accumulation of astrocytes at sites of A beta deposition. It is desirable to find methods of tipping the balance towards anti-inflammatory state. Estrogenic compounds have shown anti-inflammatory and also antioxidant activity. Astrocytes were pretreated with 17-beta estradiol or with genistein, and 48 h later treated with 5 microM amyloid beta (A beta) for 24 h. We found that A beta induces inflammatory mediators, such as cyclooxygenase 2 (…

Vitamin A deficiency causes oxidative damage to liver mitochondria in rats.

Mitochondrial damage in rat liver induced by chronic vitamin A-deficiency was studied using three different groups of rats: (i) control rats, (ii) rats fed a vitamin A-free diet until 50 d after birth and (iii) vitamin A-deficient rats re-fed a control diet for 30 d. No statistical difference in body weight and food intake was found between control and vitamin A-deficient rats. Liver GSH concentration was similar in both groups. However, in vitamin A-deficient rats, the mitochondrial GSH/GSSG ratio was significantly lower and the levels of malondialdehyde (MDA) and 8-oxo-7, 8-dihydro-2'-deoxyguanosine (oxo8dG) were higher when compared to control rats. These values were partially restored i…

Mitochondrial oxidative stress and CD95 ligand: A dual mechanism for hepatocyte apoptosis in chronic alcoholism

Apoptosis plays an important role in the progression of alcohol-induced liver disease to cirrhosis. Oxidative stress is an early event in the development of apoptosis. The major aim of this study was to study the conditions in which oxidative stress occurs in chronic alcoholism and its relationship with apoptosis of hepatocytes. We have found that oxidative stress is associated with chronic ethanol consumption in humans and in rats, in the former independently of the existence of alcohol-induced liver disease. Ethanol or acetaldehyde induces apoptosis in hepatocytes isolated from alcoholic rats, but not in those from control rats. Inhibition of aldehyde dehydrogenase, but not of cytochrome …

Mitochondrial biogenesis in health and disease. Molecular and therapeutic approaches.

Mitochondrial biogenesis (MB) is the essential mechanism by which cells control the number of mitochondria. Cells respond to different physiologic, metabolic, and pathologic changes by regulating this organelle with high morphological and functional adaptability. A considerable number of proteins, transcription factors, upstream regulatory proteins and secondary mechanisms are involved in MB and the stabilization of new mitochondrial DNA. These MB activators and regulators, including the main participating proteins (e.g. PGC-1α and mtTFA), are candidates for therapeutic intervention in diverse diseases, like neurodegenerative disorders, metabolic syndrome, sarcopenia, cardiac pathophysiolo…

Free Radicals and Antioxidants in Physical Exercise

The beneficial effects of exercise are well documented. Indeed, it ameliorates diabetes mellitus, improves the plasma lipid profile, increases bone density and may help to lose weight. However, as stated in the old medical saying “the beneficial effects of exercise are lost with exhaustion”. It has been known for some time that exhaustive exercise causes muscle soreness, induces an elevation of cytosolic enzyme activities in blood plasma and may be harmful. In the last decade a considerable amount of information concerning production of free radicals in exhaustive exercise has been obtained. An international symposium took place in Valencia, Spain in 1993 and a book was published on the sub…

Mitochondrial defects and neuromuscular degeneration caused by altered expression of Drosophila Gdap1: implications for the Charcot–Marie–Tooth neuropathy

One of the genes involved in Charcot-Marie-Tooth (CMT) disease, an inherited peripheral neuropathy, is GDAP1. In this work, we show that there is a true ortholog of this gene in Drosophila, which we have named Gdap1. By up- and down-regulation of Gdap1 in a tissue-specific manner, we show that altering its levels of expression produces changes in mitochondrial size, morphology and distribution, and neuronal and muscular degeneration. Interestingly, muscular degeneration is tissue-autonomous and not dependent on innervation. Metabolic analyses of our experimental genotypes suggest that alterations in oxidative stress are not a primary cause of the neuromuscular degeneration but a long-term c…

Gender and age-dependent differences in the mitochondrial apoptogenic pathway in Alzheimer's disease

Age-related mitochondrial oxidative stress is highly gender dependent. The aim of this study was to determine the role of gender in the mitochondrial contribution to neuronal apoptosis in Alzheimer's disease (AD). We used mitochondria isolated from brains of Wistar rats to study the toxicity of ss-amyloid peptide (Ass), and found that it increases mitochondrial peroxide production, nitration and oxidation of proteins, and release of cytochrome c. The toxic effects occurred in young males and in old females but not in young females, indicating their resistance to Ass. This resistance was abolished with age. These toxic effects of Ass were prevented by heme. Our findings provide a molecular m…

Resuscitation with room air instead of 100% oxygen prevents oxidative stress in moderately asphyxiated term neonates.

Background. Traditionally, asphyxiated newborn infants have been ventilated using 100% oxygen. However, a recent multinational trial has shown that the use of room air was just as efficient as pure oxygen in securing the survival of severely asphyxiated newborn infants. Oxidative stress markers in moderately asphyxiated term newborn infants resuscitated with either 100% oxygen or room air have been studied for the first time in this work. Methods. Eligible term neonates with perinatal asphyxia were randomly resuscitated with either room air or 100% oxygen. The clinical parameters recorded were those of the Apgar score at 1, 5, and 10 minutes, the time of onset of the first cry, and the tim…

Gender- and age-related distinctions for the in vivo prooxidant state in Fanconi anaemia patients.

Abstract Some selected oxidative stress parameters were measured in 56 Fanconi anaemia (FA) patients (42 untransplanted and 14 transplanted), 54 FA heterozygotes (parents) and 173 controls. Untransplanted FA patients showed a highly significant increase in leukocyte 8-hydroxy-2’-deoxyguanosine (8-OHdG) (p = 0.00003) and a borderline increase (p = 0.076) in urinary levels of 8-OHdG vs. child controls. These increases were more pronounced in female FA patients (p = 0.00005 for leukocyte 8-OHdG, and p = 0.021 for urinary 8-OHdG). Female FA patients also displayed a highly significant excess of spontaneous chromosomal breaks vs. male patients (p = 0.00026), in the same female:male ratio (≅ 1.4)…

Glutathione levels in blood from ataxia telangiectasia patients suggest in vivo adaptive mechanisms to oxidative stress

Objective: To evaluate an in vivo pro-oxidant state in patients with ataxia telangiectasia (AT). Methods: A set of oxidative stress endpoints were measured in 9 AT homozygotes, 16 AT heterozygotes (parents) and 83 controls (grouped in age ranges as for patients and parents, respectively). The following analytes were measured: (a) leukocyte 8-hydroxy-2-deoxyguanosine (8-OHdG); (b) blood glutathione (GSSG and GSH); and (c) plasma levels of glyoxal (Glx) and methylglyoxal (MGlx). Results: AT patients displayed a significant decrease in blood GSSG (p=0.012) and in MGlx plasma concentrations (P=0.012). A nonsignificant decrease in the GSSG:GSH ratio (p = 0.1) and a non-significant increase in 8-…

A new mass spectrometry-based method for the quantification of histones in plasma from septic shock patients.

The aim of this study was to develop a novel method to detect circulating histones H3 and H2B in plasma based on multiple reaction monitoring targeted mass spectrometry and a multiple reaction monitoring approach (MRM-MS) for its clinical application in critical bacteriaemic septic shock patients. Plasma samples from 17 septic shock patients with confirmed bacteraemia and 10 healthy controls were analysed by an MRM-MS method, which specifically detects presence of histones H3 and H2B. By an internal standard, it was possible to quantify the concentration of circulating histones in plasma, which were significantly higher in patients, and thus confirmed their potential as biomarkers for diagn…

Vitamin E deficiency induces liver nuclear factor-κB DNA-binding activity and changes in related genes

The biological functions of vitamin E have been classically attributed to its property as a potent inhibitor of lipid peroxidation in cellular membranes. However, in 1991, Azzi's group first described that alpha-tocopherol inhibits smooth muscle cell proliferation in a protein kinase C (PKC)-dependent way, demonstrating a non-antioxidant cell signalling function for vitamin E. More recently, the capacity of alpha-tocopherol to modulate gene expression with the implication of different transcription factors, beyond its antioxidant properties, has also been established. This study was to determine the effect of vitamin E-deficiency on liver nuclear factor-kappa B (NF-kappaB) DNA-binding activ…

Epigenetics and role of glutathione in redox regulation

Reversible Axonal Dystrophy by Calcium Modulation in Frataxin-Deficient Sensory Neurons of YG8R Mice

15 Pages, 8 Figures. The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fnmol.2017.00264/full#supplementary-material

Oxidative Stress and Inflammation in COVID-19-Associated Sepsis: The Potential Role of Anti-Oxidant Therapy in Avoiding Disease Progression

Since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak emerged, countless efforts are being made worldwide to understand the molecular mechanisms underlying the coronavirus disease 2019 (COVID-19) in an attempt to identify the specific clinical characteristics of critically ill COVID-19 patients involved in its pathogenesis and provide therapeutic alternatives to minimize COVID-19 severity. Recently, COVID-19 has been closely related to sepsis, which suggests that most deceases in intensive care units (ICU) may be a direct consequence of SARS-CoV-2 infection-induced sepsis. Understanding oxidative stress and the molecular inflammation mechanisms contributing to COVI…

Role of glutathione in the regulation of epigenetic mechanisms in disease

Epigenetics is a rapidly growing field that studies gene expression modifications not involving changes in the DNA sequence. Histone H3, one of the basic proteins in the nucleosomes that make up chromatin, is S-glutathionylated in mammalian cells and tissues, making Gamma-L-glutamyl-L-cysteinylglycine, glutathione (GSH), a physiological antioxidant and second messenger in cells, a new post-translational modifier of the histone code that alters the structure of the nucleosome. However, the role of GSH in the epigenetic mechanisms likely goes beyond a mere structural function. Evidence supports the hypothesis that there is a link between GSH metabolism and the control of epigenetic mechanisms…

The role of mitochondrial oxidative stress in aging.

Mitochondria are both a major source of oxidants and a target for their damaging effects, and, therefore, mitochondrial oxidative stress appears to be a cause, rather than a consequence, of cell aging. Oxidative damage in aging is particularly high in specific molecular targets, such as mitochondrial DNA and aconitase, and mitochondrial oxidative stress may drive tissue aging through intrinsic apoptosis. Mitochondrial function and morphology are impaired upon aging, as judged by a decline in membrane potential as well as by an increase in peroxide production and size of the organelles. In view of the age-related decreases in mitochondrial protein synthesis, mitochondrial transcripts, and ex…

Posibles mecanismos por los que las mujeres viven más ue los varones

Resumen Nuestro grupo ha estudiado el estres oxidativo mitocondrial en machos y hembras para tratar de dilucidar los mecanismos moleculares por los cuales las hembras son mas longevas que los machos. Las mitocondrias son la fuente principal generadora de radicales libres en las celulas. Las mitocondrias aisladas de ratas hembra producen aproximadamente la mitad de peroxidos en comparacion con las mitocondrias aisladas de sus congeneres machos. Sin embargo, la ovariectomia de las ratas conduce a una produccion de peroxidos comparable a la obtenida en los machos. La terapia sustitutiva con estrogenos previene el efecto causado por la ovariectomia. Ademas, los valores de glutation son mayores …

Decreasing xanthine oxidase-mediated oxidative stress prevents useful cellular adaptations to exercise in rats

Reactive oxygen or nitrogen species (RONS) are produced during exercise due, at least in part, to the activation of xanthine oxidase. When exercise is exhaustive they cause tissue damage; however, they may also act as signals inducing specific cellular adaptations to exercise. We have tested this hypothesis by studying the effects of allopurinol-induced inhibition of RONS production on cell signalling pathways in rats submitted to exhaustive exercise. Exercise caused an activation of mitogen-activated protein kinases (MAPKs: p38, ERK 1 and ERK 2), which in turn activated nuclear factor κB (NF-κB) in rat gastrocnemius muscle. This up-regulated the expression of important enzymes associated w…

Different patterns of in vivo pro-oxidant states in a set of cancer- or aging-related genetic diseases

A comparative evaluation is reported of pro-oxidant states in 82 patients with ataxia telangectasia (AT), Bloom syndrome (BS), Down syndrome (DS), Fanconi anemia (FA), Werner syndrome (WS), and xeroderma pigmentosum (XP) vs 98 control donors. These disorders display cancer proneness, and/or early aging, and/or other clinical features. The measured analytes were: (a) leukocyte and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), (b) blood glutathione (GSSG and GSH), (c) plasma glyoxal (Glx) and methylglyoxal (MGlx), and (d) some plasma antioxidants [uric acid (UA) and ascorbic acid (AA)]. Leukocyte 8-OHdG levels ranked as follows: WS>BS approximately FA approximately XP>DS approximately AT appr…

Aging-Related Disorders and Mitochondrial Dysfunction: A Critical Review for Prospect Mitoprotective Strategies Based on Mitochondrial Nutrient Mixtures.

A number of aging-related disorders (ARD) have been related to oxidative stress (OS) and mitochondrial dysfunction (MDF) in a well-established body of literature. Most studies focused on cardiovascular disorders (CVD), type 2 diabetes (T2D), and neurodegenerative disorders. Counteracting OS and MDF has been envisaged to improve the clinical management of ARD, and major roles have been assigned to three mitochondrial cofactors, also termed mitochondrial nutrients (MNs), i.e., alpha-lipoic acid (ALA), Coenzyme Q10 (CoQ10), and carnitine (CARN). These cofactors exert essential-and distinct-roles in mitochondrial machineries, along with strong antioxidant properties. Clinical trials have mostly…

In vivoprooxidant state in Werner syndrome (WS): Results from three WS patients and two WS heterozygotes

The hypothesis was tested that Werner syndrome (WS) phenotype might be associated with an in vivo prooxidant state. A set of redox-related endpoints were measured in three WS patients, two of their parents, and 99 controls within a study of some cancer-prone and/or ageing-related genetic disorders. The following analytes were measured: (a) leukocyte 8-hydroxy-2'-deoxyguanosine; (b) glutathione from whole blood, and (c) plasma levels of glyoxal, methylglyoxal, 8-isoprostane, and some plasma antioxidants (uric acid, ascorbic acid, alpha- and gamma-tocopherol). Leukocyte 8-hydroxy-2'-deoxyguanosine levels showed a significant increase in the 3 WS patients vs. 85 controls (p<10(-7)). The disulf…

Thioredoxin (Trxo1) interacts with proliferating cell nuclear antigen (PCNA) and its overexpression affects the growth of tobacco cell culture.

Thioredoxins (Trxs), key components of cellular redox regulation, act by controlling the redox status of many target proteins, and have been shown to play an essential role in cell survival and growth. The presence of a Trx system in the nucleus has received little attention in plants, and the nuclear targets of plant Trxs have not been conclusively identified. Thus, very little is known about the function of Trxs in this cellular compartment. Previously, we studied the intracellular localization of PsTrxo1 and confirmed its presence in mitochondria and, interestingly, in the nucleus under standard growth conditions. In investigating the nuclear function of PsTrxo1 we identified proliferati…

Extracellular histones disarrange vasoactive mediators reléase through COX-NOS interaction in human endothelial cells

Abstract Extracellular histones are mediators of inflammation, tissue injury and organ dysfunction. Interactions between circulating histones and vascular endothelial cells are key events in histone‐mediated pathologies. Our aim was to investigate the implication of extracellular histones in the production of the major vasoactive compounds released by human endothelial cells (HUVECs), prostanoids and nitric oxide (NO). HUVEC exposed to increasing concentrations of histones (0.001 to 100 μg/ml) for 4 hrs induced prostacyclin (PGI2) production in a dose‐dependent manner and decreased thromboxane A2 (TXA2) release at 100 μg/ml. Extracellular histones raised cyclooxygenase‐2 (COX‐2) and prostac…

Mitochondrial function in liver disease.

Oxidative stress is involved in the pathogenesis and progression of different liver diseases, such as alcoholic liver disease and biliary cirrhosis. The increased mitochondrial production of O2(-) at complexes I and III, and consequently of H2O2 and other reactive oxygen species (ROS), triggered by NADH overproduction seems the major cause of mitochondrial and cellular oxidative stress and damage in chronic alcoholism. The mitochondrial oxidative stress renders hepatocytes susceptible to ethanol- or acetaldehyde-induced mitochondrial membrane permeability transition (MMPT) and apoptosis. Nitrosative stress contributes to cell death by peroxynitrite formation. The expression of the death rec…

Disarrangement of Endoplasmic reticulum-mitochondria communication impairs Ca2+ homeostasis in FRDA

AbstractFriedreich ataxia (FRDA) is a neurodegenerative disorder characterized by neuromuscular and neurological manifestations. It is caused by mutations in gene FXN, which results in loss of the mitochondrial protein frataxin. Endoplasmic Reticulum-mitochondria associated membranes (MAMs) are inter-organelle structures involved in the regulation of essential cellular processes, including lipid metabolism and calcium signaling. In the present study, we have analyzed in both, unicellular and multicellular models of FRDA, an analysis of calcium management and of integrity of MAMs. We observed that function of MAMs is compromised in our cellular model of FRDA, which was improved upon treatmen…

Epigenetics As The Driving Force In Long-Term Immunosuppression

Epigenetics is an emerging frontier of biology, with the potential for deciphering the intricate molecular and transcriptional cellular programs, therefore contributing to explain the pathological evolution of sepsis, one of the most elusive syndromes in medicine. The evolution of sepsis depends not only on the pathogen which originated the infection but also on the genetic and epigenetic background of the host. Short-term mortality of sepsis and septic shock is high, being considered a public health concern worldwide. Immunosuppression is the predominant driving force for morbidity and mortality in late deaths and long-term deaths of survivors from a sepsis episode. In this regard, apoptos…

Mechanism of Free Radical Production in Exhaustive Exercise in Humans and Rats; Role of Xanthine Oxidase and Protection by Allopurinol

Exhaustive exercise generates free radicals, However, the source of this oxidative damage remains controversial. The aim of this paper was to study further the mechanism of exercise-induced production of free radicals, Testing the hypothesis that xanthine oxidase contributes to the production of free radicals during exercise, me found not only that exercise caused an increase in blood xanthine oxidase activity in rats but also that inhibiting xanthine oxidase with allopurinol prevented exercise-induced oxidation of glutathione in both rats and in humans. Furthermore, inhibiting xanthine oxidase prevented the increases in the plasma activity of cytosolic enzymes (lactate dehydrogenase, aspar…

Glutathione and cellular redox control in epigenetic regulation.

Epigenetics is defined as the mitotically/meiotically heritable changes in gene expression that are not due to changes in the primary DNA sequence. Over recent years, growing evidence has suggested a link between redox metabolism and the control of epigenetic mechanisms. The effect of the redox control, oxidative stress, and glutathione (GSH) on the epigenetic mechanisms occur at different levels affecting DNA methylation, miRNAs expression, and histone post-translational modifications (PTMs). Furthermore, a number of redox PTMs are being described, so enriching the histone code. Pioneer works showed how oxidized GSH inhibits the activity of S-adenosyl methionine synthetase, MAT1A, a key en…

Increased plasma xanthine oxidase activity is related to nuclear factor kappa beta activation and inflammatory markers in familial combined hyperlipidemia

Abstract Background and aims Xanthine oxidase (XO) has been described as one of the major enzymes producing free radicals in blood. Oxidative stress and inflammatory processes have been implicated in the pathogenesis of endothelial dysfunction and the progression of atherosclerosis but until now, there is little data about the influence of vascular prooxidant systems and inflammation in familial combined hyperlipidemia (FCH). Our goal was to evaluate whether XO activity was altered in FCH and if it was related to the inflammatory process represented by NFkB, IL-6 and hsCRP, and assessing the correlation between XO activity and insulin resistance (IR). Method and results 40 Non-related subje…

Re-definition and supporting evidence toward Fanconi Anemia as a mitochondrial disease: Prospects for new design in clinical management

Fanconi anemia (FA) has been investigated since early studies based on two definitions, namely defective DNA repair and proinflammatory condition. The former definition has built up the grounds for FA diagnosis as excess sensitivity of patients' cells to xenobiotics as diepoxybutane and mitomycin C, resulting in typical chromosomal abnormalities. Another line of studies has related FA phenotype to a prooxidant state, as detected by both in vitro and ex vivo studies. The discovery that the FA group G (FANCG) protein is found in mitochondria (Mukhopadhyay et al., 2006) has been followed by an extensive line of studies providing evidence for multiple links between other FA gene products and mi…

Physical exercise as an epigenetic modulator: Eustress, the "positive stress" as an effector of gene expression.

Physical exercise positively influences epigenetic mechanisms and improves health. Several issues remain unclear concerning the links between physical exercise and epigenetics. There is growing concern about the negative influence of excessive and persistent physical exercise on health. How an individual physically adapts to the prevailing environmental conditions might influence epigenetic mechanisms and modulate gene expression. In this article, we put forward the idea that physical exercise, especially long-term repetitive strenuous exercise, positively affects health, reduces the aging process, and decreases the incidence of cancer through induced stress and epigenetic mechanisms. We pr…

Direct antioxidant and protective effect of estradiol on isolated mitochondria

AbstractEstrogens have antioxidant properties which are due to their ability to bind to estrogen receptors and to up-regulate the expression of antioxidant enzymes via intracellular signalling pathways. Mitochondria are key organelles in the development of age-associated cellular damage. Recently, estrogen receptors were identified in mitochondria. The aim of this paper was to test whether estradiol directly affects mitochondria by preventing oxidative stress and protecting frail mitochondria. Incubation with estradiol at normal intracellular concentrations prevents the formation of reactive oxygen species by mitochondria in a saturable manner. Moreover, estradiol protects mitochondrial int…

Lafora disease fibroblasts exemplify the molecular interdependence between thioredoxin 1 and the proteasome in mammalian cells

13 páginas, 8 figuras (que no aparecen en este documento, se pueden consultar en: http://www.sciencedirect.com/science/article/pii/S0891584913003274#ec0005)

Inhibition of liver trans-sulphuration pathway by propargylglycine mimics gene expression changes found in the mammary gland of weaned lactating rats: role of glutathione

In the lactatingmammary gland, weaning produces mitochondrial cytochrome c release and nuclear DNA fragmentation, as determined by gel electrophoresis. This is followed by a significant decrease in lactation. Weaning for 2 h produces an early induction of the tumour suppressor/transcription factor p53, whereas the oncoprotein c-Jun and c-Jun N-terminal kinase are elevated after 24 h of weaning when compared with controls. The expression of p21cip1 and p27kip1, cyclin-dependent kinase inhibitors, was significantly higher in weaned rats when compared with control lactating rats. All the changes mentioned above also happen in the lactatingmammary gland when propargylglycine, an inhibitor of th…

[35] Determination of oxidized glutathione in blood: High-performance liquid chromatography

Publisher Summary The measurement of glutathione status is important in determining oxidative stress in tissues and biological fluids. The ratio of reduced to oxidized glutathione (GSH/GSSG) is a good indicator of the oxidative stress that may occur under physiological and pathological conditions. Changes in GSSG levels have been considered as intracellular signals able to modulate enzyme activity. Thus, it is important to have accurate methods to determine GSSG in biological fluids and in cells. In many cases, it is possible to use tissues, such as liver, muscle, or brain to determine GSH/GSSG. However, especially in human studies, samples from these tissues are not readily available; the …

Mitochondrial biogenesis in exercise and in ageing☆

Mitochondrial biogenesis is critical for the normal function of cells. It is well known that mitochondria are produced and eventually after normal functioning they are degraded. Thus, the actual level of mitochondria in cells is dependent both on the synthesis and the degradation. Ever since the proposal of the mitochondrial theory of ageing by Jaime Miquel in the 70's, it was appreciated that mitochondria, which are both a target and a source of radicals in cells, are most important organelles to understand ageing. Thus, a common feature between cell physiology of ageing and exercise is that in both situations mitochondria are critical for normal cell functioning. Mitochondrial synthesis i…

Cofilin and Neurodegeneration: New Functions for an Old but Gold Protein

Cofilin is an actin-binding protein that plays a major role in the regulation of actin dynamics, an essential cellular process. This protein has emerged as a crucial molecule for functions of the nervous system including motility and guidance of the neuronal growth cone, dendritic spine organization, axonal branching, and synaptic signalling. Recently, other important functions in cell biology such as apoptosis or the control of mitochondrial function have been attributed to cofilin. Moreover, novel mechanisms of cofilin function regulation have also been described. The activity of cofilin is controlled by complex regulatory mechanisms, with phosphorylation being the most important, since t…

Oxidative stress biomarkers in four Bloom syndrome (BS) patients and in their parents suggest in vivo redox abnormalities in BS phenotype.

Objective: To evaluate an association of Bloom syndrome (BS) phenotype with an in vivo prooxidant state. Methods: The following endpoints were measured in 4 BS patients, their 6 parents, and 78 controls: a) leukocyte and urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG); b) blood glutathione (GSSG and GSH), c) plasma levels of some plasma antioxidants (uric acid, UA, ascorbic acid, AA, α- and γ-tocopherol), and of glyoxal (Glx) and methylglyoxal (MGlx). Results: Leukocyte 8-OHdG levels were significantly increased in the 4 BS patients vs. 40 controls (p = 0.04), while the urinary 8-OHdG levels were non-significantly increased in BS patients. Glutathione disulfide levels and GSSG/GSH ratio were s…

Bone marrow cell transcripts from Fanconi anaemia patients revealin vivoalterations in mitochondrial, redox and DNA repair pathways

Fanconi anaemia (FA) is a genetic cancer predisposition disorder associated with cytogenetic instability, bone marrow failure and a pleiotropic cellular phenotype, including low thresholds of responses to oxidative stress, cross-linking agents and selected cytokines. This study was aimed at defining the scope of abnormalities in gene expression using the publicly available FA Transcriptome Consortium (FTC) database (Gene Expression Omnibus, 2009 and publicly available as GSE16334). We evaluated the data set that included transcriptomal analyses on RNA obtained from low-density bone marrow cells (BMC) from 20 patients with FA and 11 healthy volunteers, by seeking to identify changes in expre…

Mitochondrial damage in aging and apoptosis.

: Mitochondria are essential to cellular aging, and free radical production by mitochondria is increased with aging. The rate of oxidant production by mitochondria correlates inversely with maximal life span of species. In many species, females live longer than males. We report that mitochondrial oxidant production by females is significantly lower than that of males. However, mitochondria from ovariectomized females have a similar oxidant production as those of males. Thus, gender difference in life span can be explained, at least in part, by different oxidant generation by mitochondria. Administration of antioxidants, such as vitamins C and E, or a Ginkgo biloba extract, protects against …

The depletion of nuclear glutathione impairs cell proliferation in 3t3 fibroblasts.

BACKGROUND:Glutathione is considered essential for survival in mammalian cells and yeast but not in prokaryotic cells. The presence of a nuclear pool of glutathione has been demonstrated but its role in cellular proliferation and differentiation is still a matter of debate. PRINCIPAL FINDINGS:We have studied proliferation of 3T3 fibroblasts for a period of 5 days. Cells were treated with two well known depleting agents, diethyl maleate (DEM) and buthionine sulfoximine (BSO), and the cellular and nuclear glutathione levels were assessed by analytical and confocal microscopic techniques, respectively. Both agents decreased total cellular glutathione although depletion by BSO was more sustaine…

Vitamin E Paradox in Alzheimer's Disease: It Does Not Prevent Loss of Cognition and May Even Be Detrimental

There is controversy as to whether vitamin E is beneficial in Alzheimer's disease (AD). In this study, we tested if vitamin E prevents oxidative stress and loss of cognition in AD. Fifty-seven AD patients were recruited and divided in two groups: placebo or treated with 800 IU of vitamin E per day for six months. Of these 57 patients, only 33 finished the study. We measured blood oxidized glutathione (GSSG) and used the following cognitive tests: Mini-Mental State Examination, Blessed-Dementia Scale, and Clock Drawing Test. Of those patients treated with vitamin E, we found two groups. In the first group, "respondents" to vitamin E, GSSG levels were lower after the treatment and scores on t…

Glutathione, oxidative stress and aging

The free radical theory of aging proposes that the impairment in physiological performance associated with aging is caused by the detrimental effects of oxygen free radicals. This is interesting because it provides us with a theoretical framework to understand aging and because it suggests a rationale for intervention, i.e., antioxidant administration. Thus, the study of antioxidant systems of the cell may be very important in gerontological studies. Glutathione is one of the main nonprotein antioxidants in the cell which, together with its related enzymes, constitute the “glutathione system.” The involvement of glutathione in aging has been known since the early seventies. Several studies …

Maintenance of glutathione levels and its importance in epigenetic regulation.

Glutathione (GSH) is present in almost all cell types playing an important function in organisms. It is the main antioxidant in many cell types and it also regulates the function of proteins, including transcription factors (reviewed in Pallardo et al., 2009; Markovic et al., 2010; Garcia-Gimenez et al., 2013a). Over recent years, growing evidence has suggested a link between GSH metabolism and the control of epigenetic mechanisms. Epigenetics is defined as the mitotically/meiotically heritable changes in gene expression that are not due to changes in the primary DNA sequence. This link between GSH and epigenetics occurs at different levels. Hence, GSH can affect DNA and histone methylation…

Circulating miR-323-3p is a biomarker for cardiomyopathy and an indicator of phenotypic variability in Friedreich’s ataxia patients

AbstractMicroRNAs (miRNAs) are noncoding RNAs that contribute to gene expression modulation by regulating important cellular pathways. In this study, we used small RNA sequencing to identify a series of circulating miRNAs in blood samples taken from Friedreich’s ataxia patients. We were thus able to develop a miRNA biomarker signature to differentiate Friedreich’s ataxia (FRDA) patients from healthy people. Most research on FDRA has focused on understanding the role of frataxin in the mitochondria, and a whole molecular view of pathological pathways underlying FRDA therefore remains to be elucidated. We found seven differentially expressed miRNAs, and we propose that these miRNAs represent …

Differential expression of PGC-1α and metabolic sensors suggest age-dependent induction of mitochondrial biogenesis in Friedreich ataxia fibroblasts.

11 pages, 6 figures. PMID:21687738[PubMed] PMCID: PMC3110204

Oxidative stress, a new hallmark in the pathophysiology of Lafora progressive myoclonus epilepsy

12 páginas, 4 figuras, 1 tabla

Implementing Precision Medicine in Human Frailty through Epigenetic Biomarkers

The main epigenetic features in aging are: reduced bulk levels of core histones, altered pattern of histone post-translational modifications, changes in the pattern of DNA methylation, replacement of canonical histones with histone variants, and altered expression of non-coding RNA. The identification of epigenetic mechanisms may contribute to the early detection of age-associated subclinical changes or deficits at the molecular and/or cellular level, to predict the development of frailty, or even more interestingly, to improve health trajectories in older adults. Frailty reflects a state of increased vulnerability to stressors as a result of decreased physiologic reserves, and even dysregu…

Amyloid-β toxicity and tau hyperphosphorylation are linked via RCAN1 in Alzheimer's disease.

Amyloid-β peptide (Aβ) toxicity and tau hyperphosphorylation are hallmarks of Alzheimer’s disease (AD). How their molecular relationships may affect the etiology, progression, and severity of the disease, however, has not been elucidated. We now report that incubation of foetal rat cortical neurons with Aβ up-regulates expression of the Regulator of Calcineurin gene RCAN1, and this is mediated by Aβ-induced oxidative stress. Calcineurin (PPP3CA) is a serine-threonine phosphatase that dephosphorylates tau. RCAN1 proteins inhibit this phosphatase activity of calcineurin. Increased expression of RCAN1 also causes up-regulation of glycogen synthase kinase-3beta (GSK3β), a tau kinase. Thus, incr…

Physiological changes in glutathione metabolism in foetal and newborn rat liver

Glutathione metabolism was studied in isolated hepatocytes from foetal, newborn and adult rats. The GSH/GSSG ratio decreased 15-20-fold through the foetal-neonatal-adult transition. This was mainly due to an increase in GSSG. All enzyme activities involved in the glutathione redox cycle tend to increase during that transition, but the relative increases in glutathione peroxidase and glutathione S-transferase were 3-5 times those of glutathione reductase or glucose-6-phosphate dehydrogenase. GSH synthesis from methionine as a sulphur source was 6 times lower in foetal than in adult hepatocytes. However, when N-acetylcysteine was used as a sulphur donor to by-pass the cystathionine pathway, t…

Non-coding RNAs and Coronary Artery Disease

Coronary artery disease (CAD) is the leading death cause worldwide. Non-coding RNA (ncRNA) are key regulators of genetic expression and thus can affect directly or indirectly the development and progression of different diseases. ncRNA can be classified in several types depending on the length or structure, as long non-coding RNA (lncRNA), microRNA (miRNA) and circularRNA (circRNA), among others. These types of RNA are present within cells or in circulation, and for this reason they have been used as biomarkers of different diseases, therefore revolutionizing precision medicine. Recent research studied the capability of circulating ncRNA to inform about CAD presence and predict the outcome …

Clinical and immunological aspects of microRNAs in neonatal sepsis

Abstract Neonatal sepsis constitutes a highly relevant public health challenge and is the most common cause of infant morbidity and mortality worldwide. Recent studies have demonstrated that during infection epigenetic changes may occur leading to reprogramming of gene expression. Post-transcriptional regulation by short non-coding RNAs (e.g., microRNAs) have recently acquired special relevance because of their role in the regulation of the pathophysiology of sepsis and their potential clinical use as biomarkers. ~22-nucleotide of microRNAs are not only involved in regulating multiple relevant cellular and molecular functions, such as immune cell function and inflammatory response, but have…

Glutathione regulates telomerase activity in 3T3 fibroblasts.

Changes in telomerase activity have been associated either with cancer, when activity is increased, or with cell cycle arrest when it is decreased. We report that glutathione, a physiological antioxidant present at high intracellular concentrations, regulates telomerase activity in cells in culture. Telomerase activity increases in 3T3 fibroblasts before exponential cell growth. The peak of telomerase activity takes place 24 h after plating and coincides with the maximum levels of glutathione in the cells. When cells are treated with buthionine sulfoximine, which decreases glutathione levels in cells, telomerase activity decreases by 60%, and cell growth is delayed. Glutathione depletion in…

Oxidative post‐translational modifications in histones

Epigenetic regulation is attracting much attention because it explains many of the effects that the external environment induces in organisms. Changes in the cellular redox status and even more specifically in its nuclear redox compartment is one of these examples. Redox changes can induce modulation of the epigenetic regulation in cells. Here we present a few cases where reactive oxygen or nitrogen species induces epigenetic marks in histones. Posttranslational modification of these proteins like histone nitrosylation, carbonylation, or glutathionylation together with other mechanisms not reviewed here are the cornerstones of redox-related epigenetic regulation. We currently face a new fie…

Assessing the risk of cytomegalovirus DNAaemia in allogeneic stem cell transplant recipients by monitoring oxidative-stress markers in plasma

The level of antioxidants, such as thiol-containing tripeptide glutathione (GSH), in cytomegalovirus (CMV)-infected cells is notably increased. We previously showed that GSH levels in plasma, as measured by untargeted 1H nuclear magnetic resonance, are higher in allogeneic stem cell transplant (allo-SCT) recipients who subsequently develop CMV viraemia. We hypothesized that the net level of oxidative-stress markers present in plasma may be reduced in patients who develop CMV DNAaemia compared to those who do not. We serially monitored the levels of malondialdehyde (MDA) and carbonylated proteins (CPs) early after allo-SCT and assessed whether they could predict the occurrence of CMV DNAaemi…

Role of non-coding RNAs as biomarkers of deleterious cardiovascular effects in sepsis.

The mechanisms occurring during sepsis that produce an increased risk of cardiovascular (CV) disease (CVD) are poorly understood. Even less information exists regarding CV dysfunction as a complication of sepsis, particularly for sepsis-induced cardiomyopathy. However, recent research has demonstrated that non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, play a crucial role in genetic reprogramming, gene regulation, and inflammation during the development of CVD. Here we describe experimental findings showing the importance of non-coding RNAs mediating relevant mechanisms underlying CV dysfunction after sepsis, so contributing to sepsis-induced cardiomyopathy. …

Late onset administration of oral antioxidants prevents age-related loss of motor co-ordination and brain mitochondrial DNA damage.

We have studied the effect of aging on brain glutathione redox ratio, on brain mitochondrial DNA damage and on motor co-ordination in mice and the possible protective role of late onset administration of sulphur-containing antioxidants. Glutathione redox ratios change to a more oxidized state in whole brain with aging but the changes are much more pronounced when this ratio is measured in brain mitochondria. The levels of 8-oxo-7,8-dihydro-2 '-deoxyguanosine in mitochondrial DNA are much higher in the brain of old animals than in those of young ones. Late onset oral administration of sulphur-containing antioxidants partially prevents oxidation of mitochondrial glutathione and DNA. There is …

Friedreich Ataxia: current state-of-the-art, and future prospects for mitochondrial-focused therapies

Friedreichs Ataxia is an autosomal recessive genetic disease causing the defective gene product, frataxin. A body of literature has been focused on the attempts to counteract frataxin deficiency and the consequent iron imbalance, in order to mitigate the disease-associated prooxidant state and clinical course. The present mini review is aimed at evaluating the basic and clinical reports on the roles and the use of a set of iron chelators, antioxidants and some cofactors involved in the key mitochondrial functions. Extensive literature has focused on the protective roles of iron chelators, coenzyme Q10 and analogs, and vitamin E, altogether with varying outcomes in clinical studies. Other st…

Circulating mononuclear cells nuclear factor-kappa B activity, plasma xanthine oxidase, and low grade inflammatory markers in adult patients with familial hypercholesterolaemia.

Eur J Clin Invest 2010; 40 (2): 89–94 Abstract Background  Few data are available on circulating mononuclear cells nuclear factor-kappa B (NF-kB) activity and plasma xanthine oxidase (XO) activity in heterozygous familial hypercholesterolaemia (FH). The goal of the study was to analyse circulating mononuclear cells NF-kB and plasma XO activities in FH patients. Materials and methods  Thirty FH index patients and 30 normoglycaemic normocholesterolaemic controls matched by age, gender, body mass index, abdominal circumference and homeostasis model assessment index were studied. Plasma XO and inflammatory markers were measured by standard methods. NF-kB was assayed in circulating mononuclear c…

Role of mitochondrial oxidative stress to explain the different longevity between genders. Protective effect of estrogens

Females live longer than males. Work from our laboratory has shown that this may be due to the up-regulation of longevity-associated genes by estrogens. Estrogens bind to the estrogen receptors and subsequently activate the mitogen activated protein kinase and nuclear factor kappa B signalling pathways, resulting in an up-regulation of antioxidant enzymes. Estrogen administration, however, has serious undesirable effects and of course, cannot be administered to males because of its powerful feminizing effects. Thus, we tested the effect of genistein, a phytoestrogen of high nutritional importance whose structure is similar to estradiol, on the regulation of the expression of antioxidant, lo…

Cellular Responses in Human Dental Pulp Stem Cells Treated with Three Endodontic Materials

Human dental pulp stem cells (HDPSCs) are of special relevance in future regenerative dental therapies. Characterizing cytotoxicity and genotoxicity produced by endodontic materials is required to evaluate the potential for regeneration of injured tissues in future strategies combining regenerative and root canal therapies. This study explores the cytotoxicity and genotoxicity mediated by oxidative stress of three endodontic materials that are widely used on HDPSCs: a mineral trioxide aggregate (MTA-Angelus white), an epoxy resin sealant (AH-Plus cement), and an MTA-based cement sealer (MTA-Fillapex). Cell viability and cell death rate were assessed by flow cytometry. Oxidative stress was m…

Rapid-rate transcranial magnetic stimulation of left dorsolateral prefrontal cortex in drug-resistant depression.

Summary Background Lesion and neuroimaging studies suggest that left prefrontal lobe dysfunction is pathophysiologically linked to depression. Rapid-rate transcranial magnetic stimulation (rTMS) to prefrontal structures has a lateralised effect on mood in normal volunteers, and several preliminary studies suggest a beneficial effect of rTMS on depression. However, adequately controlled studies have not been conducted. Methods We have studied the effects of focal rTMS on the depressive symptoms in 17 patients with medication-resistant depression of psychotic subtype. The study was designed as a multiple cross-over, randomised placebo-controlled trial. Sham rTMS and stimulation of different c…

DNA Methylation Analysis to Unravel Altered Genetic Pathways Underlying Early Onset and Late Onset Neonatal Sepsis. A Pilot Study

Background: Neonatal sepsis is a systemic condition widely affecting preterm infants and characterized by pro-inflammatory and anti-inflammatory responses. However, its pathophysiology is not yet fully understood. Epigenetics regulates the immune system, and its alteration leads to the impaired immune response underlying sepsis. DNA methylation may contribute to sepsis-induced immunosuppression which, if persistent, will cause long-term adverse effects in neonates.Objective: To analyze the methylome of preterm infants in order to determine whether there are DNA methylation marks that may shed light on the pathophysiology of neonatal sepsis.Design: Prospective observational cohort study perf…

Circular RNAs in Sepsis: Biogenesis, Function, and Clinical Significance

Sepsis is a life-threatening condition that occurs when the body responds to an infection that damages it is own tissues. The major problem in sepsis is rapid, vital status deterioration in patients, which can progress to septic shock with multiple organ failure if not properly treated. As there are no specific treatments, early diagnosis is mandatory to reduce high mortality. Despite more than 170 different biomarkers being postulated, early sepsis diagnosis and prognosis remain a challenge for clinicians. Recent findings propose that circular RNAs (circRNAs) may play a prominent role in regulating the patients’ immune system against different pathogens, including bacteria and viruses. Mou…

Oxidative stress modulates rearrangement of endoplasmic reticulum-mitochondria contacts and calcium dysregulation in a Friedreich's ataxia model

Friedreich ataxia (FRDA) is a neurodegenerative disorder characterized by neuromuscular and neurological manifestations. It is caused by mutations in the FXN gene, which results in loss of the mitochondrial protein frataxin. Endoplasmic Reticulum-mitochondria associated membranes (MAMs) are inter-organelle structures involved in the regulation of essential cellular processes, including lipid metabolism and calcium signaling. In the present study, we have analyzed in both, unicellular and multicellular models of FRDA, calcium management and integrity of MAMs. We observed that function of MAMs is compromised in our cellular model of FRDA, which was improved upon treatment with antioxidants. I…

From genetics to epigenetics to unravel the etiology of adolescent idiopathic scoliosis.

Scoliosis is defined as the three-dimensional (3D) structural deformity of the spine with a radiological lateral Cobb angle (a measure of spinal curvature) of ≥10° that can be caused by congenital, developmental or degenerative problems. However, those cases whose etiology is still unknown, and affect healthy children and adolescents during growth, are the commonest form of spinal deformity, known as adolescent idiopathic scoliosis (AIS). In AIS management, early diagnosis and the accurate prediction of curve progression are most important because they can decrease negative long-term effects of AIS treatment, such as unnecessary bracing, frequent exposure to radiation, as well as saving the…

L-cysteine and glutathione metabolism are impaired in premature infants due to cystathionase deficiency.

There are conflicting reports in the literature as to whether L-cysteine is an essential amino acid in premature infants as the result of the absence of hepatic cystathionase activity. To analyze the physiological importance of the cystathionase deficiency, we studied sulfur amino acid metabolism in human neonates of different gestational ages. Plasma cystathionine concentrations are higher in premature infants < or = 32 wk gestation (group 1) than in premature infants of 33-36 wk gestational age (group 2) or in full-term infants (group 3), whereas plasma cysteine concentrations are much lower in group 1 and 2 premature infants than in mature infants. Furthermore, erythrocytes from group 1 …

Epigenetic biomarkers: A new perspective in laboratory diagnostics.

Epigenetics comprises the study of chemical modifications in the DNA and histones that regulates the gene expression or cellular phenotype. However, during the last decade this term has evolved after the elucidation of different mechanisms (microRNAs and nuclear organization of the chromosomes) involved in regulating gene expression. Epigenetics and the new designed technologies capable to analyze epigenetic changes (e.g., methylated DNA, miRNAs expression, post-translational modifications on histones among others) have disclosed an appealing scenario that will offer for the biomedical sciences new biomarkers for the study of neurodegenerative diseases, multifactorial complex diseases, rare…

Epigenetic biomarkers for human sepsis and septic shock: insights from immunosuppression

Sepsis is a life-threatening condition that occurs when the body responds to an infection damaging its own tissues. Sepsis survivors sometimes suffer from immunosuppression increasing the risk of death. To our best knowledge, there is no ‘gold standard’ for defining immunosuppression except for a composite clinical end point. As the immune system is exposed to epigenetic changes during and after sepsis, research that focuses on identifying new biomarkers to detect septic patients with immunoparalysis could offer new epigenetic-based strategies to predict short- and long-term pathological events related to this life-threatening state. This review describes the most relevant epigenetic mecha…

Small RNA-seq analysis of circulating miRNAs to identify phenotypic variability in Friedreich's ataxia patients.

AbstractFriedreich’s ataxia (FRDA; OMIM 229300), an autosomal recessive neurodegenerative mitochondrial disease, is the most prevalent hereditary ataxia. In addition, FRDA patients have shown additional non-neurological features such as scoliosis, diabetes, and cardiac complications. Hypertrophic cardiomyopathy, which is found in two thirds of patients at the time of diagnosis, is the primary cause of death in these patients. Here, we used small RNA-seq of microRNAs (miRNAs) purified from plasma samples of FRDA patients and controls. Furthermore, we present the rationale, experimental methodology, and analytical procedures for dataset analysis. This dataset will facilitate the identificatio…

Acute depletion of telomerase components DKC1 and NOP10 induces oxidative stress and disrupts ribosomal biogenesis via NPM1 and activation of the P53 pathway.

Mutations in DKC1, NOP10, and TINF2 genes, coding for proteins in telomerase and shelterin complexes, are responsible for diverse diseases known as telomeropathies and ribosomopathies, including dyskeratosis congenita (DC, ORPHA 1775). These genes contribute to the DC phenotype through mechanisms that are not completely understood. We previously demonstrated in models of DC that oxidative stress is an early and independent event that occurs prior to telomere shortening. To clarify the mechanisms that induce oxidative stress, we silenced genes DKC1, NOP10, and TINF2 with siRNA technology. With RNA array hybridisation, we found several altered pathways for each siRNA model. Afterwards, we ide…

AZT treatment induces molecular and ultrastructural oxidative damage to muscle mitochondria. Prevention by antioxidant vitamins.

AIDS patients who receive zidovudine (AZT) frequently suffer from myopathy. This has been attributed to mitochondrial (mt) damage, and specifically to the loss of mtDNA. This study examines whether AZT causes oxidative damage to DNA in patients and to skeletal muscle mitochondria in mice, and whether this damage may be prevented by supranutritional doses of antioxidant vitamins. Asymptomatic HIV-infected patients treated with AZT have a higher urinary excretion (355+/-100 pmol/kg/d) of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxo-dG) (a marker of oxidative damage to DNA) than untreated controls (asymptomatic HIV-infected patients) (182+/-29 pmol/kg/d). This was prevented (110+/-79 pmol/kg/d)…

Exercise induces oxidative stress in healthy subjects and in chronic obstructive pulmonary disease patients

Effect of nonprotein thiols on protein synthesis in isolated rat hepatocytes.

The ability of nonprotein thiols to modulate rates of protein synthesis was investigated in isolated rat hepatocytes. Addition of cysteine stimulates protein labelling by [14C]Leucine. Glutathione depletion, induced by in vivo administration of L-buthionine sulfoximine and diethylmaleate, did not alter the effect of cysteine, although it decreased the rate of protein synthesis by 32%. The effect of cysteine on protein synthesis does not seem to be related to a perturbation of the redox state of the NAD+/NADH system or to changes in the rate of gluconeogenic pathway. The following observations indicate that cysteine may stimulate protein synthesis by increasing intracellular levels of aspart…

Role of GSH in the modulation of NOS-2 expression in the weaned mammary gland

GSH delivery to the lactating mammary gland is essential for the maintenance of lactation as its decrease leads to apoptosis and involution of the mammary gland. In fact, it has already been demonstrated that some of the changes in gene expression found in the lactating mammary gland after forced weaning are reproduced in rats treated with buthionine sulphoximine to deplete GSH levels. An oligonucleotide microarray experiment would give us a better knowledge of the mRNA expression patterns during lactation and after weaning and the possible functions of GSH in the modulation of these events.

Estudio de la lipogénesis de novo en ratas alimentadas ad libitum y con dieta a tiempo restringido

Disruption of the antioxidant shield in fibroblasts from Werner syndrome

PPAR gamma agonist leriglitazone improves frataxin-loss impairments in cellular and animal models of Friedreich Ataxia

Friedreich ataxia (FRDA), the most common autosomal recessive ataxia, is characterized by degeneration of the large sensory neurons and spinocerebellar tracts, cardiomyopathy, and increased incidence in diabetes. The underlying pathophysiological mechanism of FRDA, driven by a significantly decreased expression of frataxin (FXN), involves increased oxidative stress, reduced activity of enzymes containing iron‑sulfur clus-ters (ISC), defective energy production, calcium dyshomeostasis, and impaired mitochondrial biogenesis, leading to mitochondrial dysfunction. The peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcriptional factor playing a key role in mito…

Sepsis and Coronavirus Disease 2019: Common Features and Anti-Inflammatory Therapeutic Approaches

Great efforts are being made worldwide to identify the specific clinical characteristics of infected critically ill patients that mediate the associated pathogenesis, including vascular dysfunction, thrombosis, dysregulated inflammation, and respiratory complications. Recently, coronavirus disease 2019 has been closely related to sepsis, which suggests that most deaths in ICUs in infected patients are produced by viral sepsis. Understanding the physiopathology of the disease that lead to sepsis after severe acute respiratory syndrome coronavirus 2 infection is a current clinical need to improve intensive care-applied therapies applied to critically ill patients. Although the whole represent…

The Relationship between Alcohol–induced Apoptosis and Oxidative Stress in the Liver

This chapter discusses the relationship of apoptosis and oxidative stress induced by alcohol in the liver. Oxidative stress is involved in the pathogenesis and progression of alcohol-induced liver disease. Chronic alcoholism always causes oxidative stress independently of the presence of liver disease. Two key mechanisms are responsible for it: (1) the mitochondrial respiratory chain and (2) cytochrome P450 2El activity. Increased production of reactive oxygen species at complexes I and III together with NADH overproduction would be the major cause for mitochondrial oxidative stress in chronic alcoholism. Reactive Oxygen Species (ROS) cause oxidative damage, which may lead to cell death by …

IGF-1 Haploinsufficiency Causes Age-Related Chronic Cochlear Inflammation and Increases Noise-Induced Hearing Loss

This article belongs to the Collection Insulin-Like Growth Factors in Development, Cancers and Aging.

Extracellular histones activate autophagy and apoptosis via mTOR signaling in human endothelial cells.

Circulating histones have been proposed as targets for therapy in sepsis and hyperinflammatory symptoms. However, the proposed strategies have failed in clinical trials. Although different mechanisms for histone-related cytotoxicity are being explored, those mediated by circulating histones are not fully understood. Extracellular histones induce endothelial cell death, thereby contributing to the pathogenesis of complex diseases such as sepsis and septic shock. Therefore, the comprehension of cellular responses triggered by histones is capital to design effective therapeutic strategies. Here we report how extracellular histones induce autophagy and apoptosis in a dose-dependent manner in cu…

Estrogenic Modulation of Longevity by Induction of Antioxidant Enzymes

In many species including humans, females live longer than males. We and others have observed that mitochondria from females of Wistar rats and of OF1 mice produce half the amount of peroxide produced by males. We attributed this to a change in the expression of antioxidant, longevity-related genes. We have found that in those species in which females live longer than males, estrogens activate longevity-related genes, particularly antioxidant ones. It should be emphasized that estrogens do not act as antioxidants because of their phenolic ring but rather they act indirectly; that is, they behave as hormones and bind to estrogen receptors, which eventually leads to the upregulation of the ex…

Corrigendum to “A Drosophila model of GDAP1 function reveals the involvement of insulin signalling in the mitochondria-dependent neuromuscular degeneration” [Biochim. Biophys. Acta 1863 (2017) 801–809]

Epigenetic Regulation in the Pathogenesis of Sjögren Syndrome and Rheumatoid Arthritis

Autoimmune rheumatic diseases, such as Sjögren syndrome (SS) and rheumatoid arthritis (RA), are characterized by chronic inflammation and autoimmunity, which cause joint tissue damage and destruction by triggering reduced mobility and debilitation in patients with these diseases. Initiation and maintenance of chronic inflammatory stages account for several mechanisms that involve immune cells as key players and the interaction of the immune cells with other tissues. Indeed, the overlapping of certain clinical and serologic manifestations between SS and RA may indicate that numerous immunologic-related mechanisms are involved in the physiopathology of both these diseases. It is widely accept…

Aging of the liver: Age-associated mitochondrial damage in intact hepatocytes

Mitochondrial damage may be a major cause of cellular aging. So far, this hypothesis had only been tested using isolated mitochondria. The aim of this study was to investigate the involvement of mitochondria in aging using whole liver cells and not isolated mitochondria only. Using flow cytometry, we found that age is associated with a decrease in mitochondrial membrane potential (30%), an increase in mitochondrial size, and an increase in mitochondrial peroxide generation (23%). Intracellular peroxide levels were also increased. The number of mitochondria per cell and inner mitochondrial membrane mass did not change. Gluconeogenesis from glycerol or fructose (mitochondrial-independent) did…

miR-1226 detection in GCF as potential biomarker of chronic periodontitis: a pilot study

Background The study and identification of new biomarkers for periodontal disease, such as microRNAs (miRNAs), may give us more information about the location and severity of the disease and will serve as a basis for treatment planning and disease-monitoring. miRNAs are a group of small RNAs which are involved in gene regulation by binding to their messenger RNA target (mRNA). In this pilot study, the procedure for purifying miRNAs from gingival crevicular fluid (GCF) was, for the first time, described. In addition, the concentration of miRNAs in GCF was analyzed and compared between patients with moderate or severe chronic periodontitis (CP) and healthy controls. Material and Methods GCF s…