Isoprostanes and 4-hydroxy-2-nonenal: markers or mediators of disease? Focus on Rett syndrome as a model of autism spectrum disorder

Physical Exercise-Induced Activation of NRF2 and BDNF as a Promising Strategy for Ferroptosis Regulation in Parkinson's Disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra. Ferroptosis, an iron-dependent form of regulated cell death, may contribute to the progression of PD owing to an unbalanced brain redox status. Physical exercise is a complementary therapy that can modulate ferroptosis in PD by regulating the redox system through the activation of nuclear factor (erythroid-derived 2)-like 2 (NRF2) and brain-derived neurotrophic factor (BDNF) signaling. However, the precise effects of physical exercise on ferroptosis in PD remain unclear. In this review, we explored how physical exercise influences NRF2 and BDNF signaling and affects ferroptosis in PD. We further investigated relevant publications over the past two decades by searching the PubMed, Web of Science, and Google Scholar databases using keywords related to physical exercise, PD, ferroptosis, and neurotrophic factor antioxidant signaling. This review provides insights into current research gaps and demonstrates the necessity for future research to elucidate the specific mechanisms by which exercise regulates ferroptosis in PD, including the assessment of different exercise protocols and their long-term effects. Ultimately, exploring these aspects may lead to the development of improved exercise interventions for the better management of patients with PD.

Molecular Responses of the Eukaryotic Cell Line INT407 on the Internalized Campylobacter jejuni-The Other Side of the Coin

Campylobacter jejuni is a zoonotic bacterium with the capacity to invade the epithelial cells during the pathogenic process. Several bacterial factors have been identified to contribute to this process, but our knowledge is still very limited about the response of the host. To reveal the major routes of this response, a whole-transcriptome analysis (WTA) was performed where gene expressions were compared between the 1st and the 3rd hours of internalization in INT407 epithelial cells. From the 41,769 human genes tested, altogether, 19,060 genes were shown through WTA to be influenced to different extents. The genes and regulation factors of transcription (296/1052; 28%), signal transduction (215/1052; 21%), apoptosis (153/1052; 15%), immune responses (97/1052; 9%), transmembrane transport (64/1052; 6%), cell-cell signaling (32/1052; 3%), cell-cell adhesions (29/1052; 3%), and carbohydrate metabolism (28/1052; 3%) were the most affected biological functions. A striking feature of the gene expression of this stage of the internalization process is the activation of both immune functions and apoptosis, which convincingly outlines that the invaded cell faces a choice between death and survival. The seemingly balanced status quo between the invader and the host is the result of a complex process that also affects genes known to be associated with postinfectious pathological conditions. The upregulation of TLR3 (3.79×) and CD36 (2.73×), two general tumor markers, and SERPINEB9 (11.37×), FNDC1 (7.58×), and TACR2 (8.84×), three factors of tumorigenesis, confirms the wider pathological significance of this bacterium.

The Relationship Between Oxidative Stress, Selenium, and Cumulative Risk in Metabolic Syndrome

BACKGROUND/AIM

Oxidative stress in association with metabolic syndrome represents a complex disease entity that has emerged as a significant public health challenge, and it is closely linked to an elevated risk of cardiovascular disease, type 2 diabetes, and even cancer. The objective of this study was to investigate the effectiveness of selenium supplementation in managing oxidative stress while considering a well-balanced diet based on a healthy lifestyle and diet therapy.

PATIENTS AND METHODS

The study included a total of 206 participants divided into three groups: the control group consisting of 35 individuals (17.0%) named LC, the diet therapy group comprising 119 individuals (57.8%) named LD, and the diet therapy group supplemented with selenium consisting of 52 individuals (25.2%) named LD+Se. Various clinical parameters such as body mass index (BMI), weight status, fat mass, visceral fat, and sarcopenia index, as well as paraclinical parameters including the HOMA index, cholesterol, triglycerides, C-reactive protein, and HGZ, were evaluated. Additionally, oxidative stress parameters using the FORD, FORT and MIXT tests were measured.

RESULTS

Selenium supplementation, along with FORD and FORT tests, demonstrated effectiveness in individuals with chronic venous disease, with a significantly greater decrease observed in those with chronic venous disease in the LD+Se group.

CONCLUSION

Physiological aging has an important role in triggering or aggravating oxidative stress, and the use of antioxidant products such as selenium can reduce this process.

Oxidative Stress Is a Concept, Not an Indication for Selective Antioxidant Treatment

The steady-state redox status is physiologically important and therefore homeostatically maintained. Changes in the status result in signaling (eustress) or oxidative damage (distress). Oxidative stress (OS) is a hard-to-quantitate term that can be estimated only based on different biomarkers. Clinical application of OS, particularly for selective antioxidant treatment of people under oxidative stress, requires quantitative evaluation and is limited by the lack of universal biomarkers to describe it. Furthermore, different antioxidants have different effects on the redox state. Hence, as long as we do not have the possibility to determine and quantify OS, therapeutic interventions by the "identify-and-treat" approach cannot be assessed and are, therefore, not likely to be the basis for selective preventive measures against oxidative damage.

Relationship between Oxidative Stress and Endometritis: Exploiting Knowledge Gained in Mares and Cows

Simple Summary

Endometritis is a widespread pathology in mares and cows and one of the leading causes of reproductive efficiency decline. Although localized in the innermost layer of the uterus, this inflammation involves the release of bioactive molecules and by-products related to molecular damage. Among the bioactive substances, a primary role is played by the reactive oxygen and nitrogen species, which, while exerting an antimicrobial effect, can amplify the inflammation, sometimes causing unwanted and self-aggravating effects. Part of these substances enters the bloodstream, with implications that range from sustaining distant effects on organs and tissues to being used as diagnostic biomarkers. The research carried out on this matter in cows and mares has maintained certain independence due to its species specificity. This review aims to collect and analyze the information available in these species to enhance diagnostics and provide new insights to prevent and treat this pathology.

Abstract

The etiopathogenesis of endometritis in mares and cows differs significantly; this could depend on a different sensitivity and reactivity of the uterus but also on endocrine and rearing factors and different stress sources. In both species, microorganisms and the immune system play a primary role in the generation of this pathology. Microbiological and cytological tests support clinical examination and significantly improve diagnostic accuracy. For both species, during the inflammation, immune cells invade the endometrium and release bioactive substances to contrast primary or secondary pathogen contamination. These molecules are traceable to cytokines, chemokines, and prostaglandins as well as reactive oxygen and nitrogen species (ROS and RNS), collectively known as RONS. The RONS-mediated oxidation causes morphological and functional alterations of macromolecules, such as proteins, lipids, and nucleic acids, with the consequent production of derivative compounds capable of playing harmful effects. These bioactive molecules and by-products, which have recently become increasingly popular as diagnostic biomarkers, enter the bloodstream, influencing the functionality of organs and tissues. This review has collected and compared information obtained in cows and mares related to the diagnostic potential of these biomarkers that are assessed by using different methods in samples from either blood plasma or uterine fluid.

Influence of Hydroxytyrosol Acetate Enrichment of an Oil Rich in Omega-6 Groups on the Evolution of Its Oxidation and Oxylipin Formation When Subjected to Accelerated Storage. A Global Study by Proton Nuclear Magnetic Resonance

Sunflower oil samples, both unenriched and enriched with four different concentrations of hydroxytyrosol acetate, were subjected to accelerated storage at 70 °C until a very advanced oxidation stage and the process was monitored by ¹H NMR spectroscopy. The aim of the study is to know the effect that the presence of this antioxidant has on the oxidation process of sunflower oil under the aforementioned conditions, as well as on the formation and evolution of the concentration of a significant number of oxylipins. The oxidation process was studied globally by monitoring, during storage time, the degradation of both the linoleic acyl group of sunflower oil, which is the main component of sunflower oil, and the added hydroxytyrosol acetate. Simultaneously, the identification of up to twenty-six different types of oxylipins formed in the oxidation process and the monitoring of the evolution of their concentration over the storage time were carried out. In this way, essential information about the effect that hydroxytyrosol acetate provokes on the oxidation of this oil rich in omega-6 polyunsaturated acyl groups, has been obtained. It has also been shown that the enrichment of sunflower oil with this antioxidant under the conditions tested does not prevent the oxidation process but slows it down, affecting the entire oxidation process.

Alaskan Bog Blueberry (Vaccinium uliginosum) Extract as an Innovative Topical Approach to Prevent UV-Induced Skin Damage

Our body is continuously exposed to various exogenous aggressors, and, in particular, the skin represents the main target for outdoor stressors, including ultraviolet (UV) radiation. UV exposure is well-known to be associated with the development/worsening of extrinsic photoaging and a multitude of skin conditions. Considering the role of photoprotection in skin health, the research of natural photoprotective molecules becomes of great importance. Therefore, in this work we wanted to evaluate the beneficial protective effects of ripe berries of Vaccinium uliginosum (Alaska bog blueberry (BB)) extract (100 μg/mL) for preventing the cutaneous oxidative, inflammatory, and structural damage induced by exposure to 200 mJ of UVA/UVB radiation. We observed that the topical application of BB extract on human ex vivo skin explants averted the UV-induced cutaneous OxInflammatory phenomenon by quenching the increase in the oxidative and inflammatory marker levels, such as 4-hydroxynonenal (4HNE), heme-oxygenase-1 (HO-1), cyclooxygenase-2 (COX2), and aryl hydrocarbon receptor (AhR); as well as by counteracting the loss of structural proteins (filaggrin and involucrin) induced by UV radiation. Our data propose the use of a topical application of Alaska bog blueberry extract as a natural and valuable approach to ensure photoprotection against UV-induced skin damage and premature aging.

Pathophysiological relationship between hypoxia associated oxidative stress, Epithelial-mesenchymal transition, stemness acquisition and alteration of Shh/ Gli-1 axis during oral sub-mucous fibrosis and oral squamous cell carcinoma

Oral sub-mucous fibrosis (OSF) is a pathophysiological state of oral cavity or oropharynx having a high chance of conversion to oral squamous cell carcinoma (OSCC). It involves fibrotic transformation of sub-epithelial matrix along with epithelial abnormalities. The present work aims to unveil the mechanistic domain regarding OSF to OSCC conversion exploring the scenario of hypoxia associated oxidative stress, epithelial-mesenchymal transition (EMT), metastasis and stemness acquisition. The study involves histopathological analysis of the diseased condition along with the exploration of oxidative stress status, assessment of mitochondrial condition, immunohistochemical analysis of HIF-1α, E-cadherin, vimentin, ERK, ALDH-1, CD133, Shh, Gli-1 and survivin expressions in the oral epithelial region together with the quantitative approach towards collagen deposition in the sub-epithelial matrix. Oxidative stress was found to be associated with type-II EMT in case of OSF attributing the development of sub-epithelial fibrosis and type-III EMT in case of OSCC favoring malignancy associated metastasis. Moreover, the acquisition of stemness during OSCC can also be correlated with EMT. Alteration of Shh and Gli-1 expression pattern revealed the mechanistic association of hypoxia with the phenotypic plasticity and disease manifestation in case of OSF as well as OSCC. Shh/ Gli-1 signaling can also be correlated with survivin mediated cytoprotective phenomenon under oxidative stress. Overall, the study established the correlative network of hypoxia associated oxidative stress, EMT and manifestation of oral pre-cancerous and cancerous condition in a holistic approach that may throw rays of hope in the therapeutic domain of the concerned diseases.

Increased isoprostanoid levels in brain from murine model of Krabbe disease - Relevance of isoprostanes, dihomo-isoprostanes and neuroprostanes to disease severity

Krabbe disease (KD) is a rare and devastating pediatric leukodystrophy caused by mutations in the galactocerebrosidase (GALC) gene. The disease leads to impaired myelin formation and extensive myelin damage in the brain. Oxidative stress is implicated in the pathogenesis of KD but insofar few information is available. The gray and white matter of the brain are rich in docosahexaenoic acid and adrenic acid respectively and under non-enzymatic oxidative stress, release isoprostanoids, i.e. F₄-neuroprostanes (F₄-NeuroPs) and F₂-dihomo-isoprostanes (F₂-dihomo-IsoPs). In this study, the formation of isoprostanoids in brain tissue was investigated in a well-established KD mouse model (twitcher) that recapitulates the human pathology. According to the genotype determinations, three groups of mice were selected: wild-type control mice (n = 13), heterozygotes mice (carriers of GALC mutations, n = 14) and homozygous twitcher mice (n = 13). Measurement of F₂-dihomo-IsoP and F₄-NeuroP levels were performed on whole brain tissue obtained at day 15 and day 35 of the life cycle. Brain isoprostanoid levels were significantly higher in the twitcher mice compared to the heterozygous and wild-type control mice. However, F₂-dihomo-IsoP and F₄-NeuroP levels did not differ in brain of day 15 compared to day 35 of the heterozygote mice. Interestingly, isoprostanoid levels were proportionally enhanced with disease severity (F₂-dihomo-IsoPs, rho = 0.54; F₄-NeuroPs, rho = 0.581; P values ≤ 0.05; n = 13). Our findings are the first to show the key role of polyunsaturated fatty acid oxidative damage to brain grey and white matter in the pathogenesis and progression of KD. This shed new insights on the biochemical indexes of KD progression, and potentially provide information for novel therapeutic targets.

Biomarkers of Oxidative Stress in Metabolic Syndrome and Associated Diseases

Metabolic syndrome (MS) represents worldwide public health issue characterized by a set of cardiovascular risk factors including obesity, diabetes, dyslipidemia, hypertension, and impaired glucose tolerance. The link between the MS and the associated diseases is represented by oxidative stress (OS) and by the intracellular redox imbalance, both caused by the persistence of chronic inflammatory conditions that characterize MS. The increase in oxidizing species formation in MS has been accepted as a major underlying mechanism for mitochondrial dysfunction, accumulation of protein and lipid oxidation products, and impairment of the antioxidant systems. These oxidative modifications are recognized as relevant OS biomarkers potentially able to (i) clarify the role of reactive oxygen and nitrogen species in the etiology of the MS, (ii) contribute to the diagnosis/evaluation of the disease's severity, and (iii) evaluate the utility of possible therapeutic strategies based on natural antioxidants. The antioxidant therapies indeed could be able to (i) counteract systemic as well as mitochondrial-derived OS, (ii) enhance the endogenous antioxidant defenses, (iii) alleviate MS symptoms, and (iv) prevent the complications linked to MS-derived cardiovascular diseases. The focus of this review is to summarize the current knowledge about the role of OS in the development of metabolic alterations characterizing MS, with particular regard to the occurrence of OS-correlated biomarkers, as well as to the use of therapeutic strategies based on natural antioxidants.

Effects of Cyclic Fatty Acid Monomers from Heated Vegetable Oil on Markers of Inflammation and Oxidative Stress in Male Wistar Rats

This study assesses the effects of cyclic fatty acid monomers (CFAM) from heated vegetable oils on oxidative stress and inflammation. Wistar rats were fed either of these four diets for 28 days: canola oil (CO), canola oil and 0.5% CFAM (CC), soybean oil (SO), and soybean oil and 0.5% CFAM (SC). Markers of oxidative stress and inflammation were determined by micro liquid chromatography tandem mass spectrometry (micro-LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) kits, respectively. Analysis of variance (ANOVA) for a 2 × 2 factorial design was performed to determine the CFAM and oil effects and interactions between these two factors at P ≤ 0.05. For significant interactions, a post hoc multiple comparison test was performed, i.e., Tukey HSD (honest significant difference) test. CFAM induced higher plasma levels of 15-F_2t-IsoP (CC, 396 ± 43 ng/mL, SC, 465 ± 75 ng/mL vs CO, 261 ± 23 ng/mL and SO, 288 ± 35 ng/mL, P < 0.05). Rats fed the SC diet had higher plasma 2,3-dinor-15-F_2t-IsoP (SC, 145 ± 9 ng/mL vs CC, 84 ± 8 ng/mL, CO, 12 ± 1 ng/mL, and SO, 12 ± 1 ng/mL, P < 0.05), urinary 2,3-dinor-15-F_2t-IsoP (SC, 117 ± 12 ng/mL vs CC, 67 ± 13 ng/mL, CO, 15 ± 2 ng/mL, and SO, 18 ± 4 ng/mL, P < 0.05), and plasma IL-6 (SC, 57 ± 10 pg/mL vs CC, 48 ± 11 pg/mL, CO, 46 ± 9 pg/mL, and SO, 44 ± 4 pg/mL, P < 0.05) than the other three diet groups. These results indicate that CFAM increased the levels of markers of oxidative stress, and those effects are exacerbated by a CFAM-high-linoleic acid diet.

OxInflammation: From Subclinical Condition to Pathological Biomarker

Inflammation is a complex systemic response evolved to cope with cellular injury, either due to infectious agents or, in general, with sporadic events challenging tissue integrity and function. Researchers involved in different fields have the tendency to look at the inflammatory response with different angles, according to their specific interest. Established its complexity, one of the most evident features of the inflammatory response is the generation of a pro-oxidative environment due to the production of high fluxes of pro-oxidant species. This production begins locally, close to the sites of tissue damage or infection, but eventually becomes a chronic challenge for the organism, if the inflammatory response is not properly controlled. In this review, we focus on this specific aspect of chronic, low-level sub-clinical inflammatory response. We propose the term "OxInflammation" as a novel operative term describing a permanent pro-oxidative feature that interact, in a positive feed-back manner, to a not yet clinically detectable inflammatory process, leading in a long run (chronically) to a systemic/local damage, as a consequence of the cross talk between inflammatory, and oxidative stress mediators. Therefore, it could be useful to analyze inflammatory markers in pathologies where there is an alteration of the redox homeostasis, although an inflammatory status is not clinically evident.

Relevance of 4-F4t-neuroprostane and 10-F4t-neuroprostane to neurological diseases

F₄-neuroprostanes (F₄-NeuroPs) are non-enzymatic oxidized products derived from docosahexaenoic acid (DHA) and are suggested to be oxidative damage biomarkers of neurological diseases. However, 128 isomers can be formed from DHA oxidation and among them, 4(RS)-4-F_4t-NeuroP (4-F_4t-NeuroP) and 10(RS)-10-F_4t-NeuroP (10-F_4t-NeuroP) are the most studied. Here, we report the identification and the clinical relevance of 4-F_4t-NeuroP and 10-F_4t-NeuroP in plasma of four different neurological diseases, including multiple sclerosis (MS), autism spectrum disorders (ASD), Rett syndrome (RTT), and Down syndrome (DS). The identification and the optimization of the method were carried out by gas chromatography/negative-ion chemical ionization tandem mass spectrometry (GC/NICI-MS/MS) using chemically synthesized 4-F_4t-NeuroP and 10-F_4t-NeuroP standards and in oxidized DHA liposome. Both 4-F_4t-NeuroP and 10-F_4t-NeuroP were detectable in all plasma samples from MS (n = 16), DS (n = 16), ASD (n = 9) and RTT (n = 20) patients. While plasma 10-F_4t-NeuroP content was significantly higher in patients of all diseases as compared to age and gender matched healthy control subjects (n = 61), 4-F_4t-NeuroP levels were significantly higher in MS and RTT as compared to healthy controls. Significant positive relationships were observed between relative disease severity and 4-F_4t-NeuroP levels (r = 0.469, P <0.0001), and 10-F_4t-NeuroP levels (r = 0.757, P < 0.0001). The study showed that the plasma amount ratio of 10-F_4t-NeuroP to 4-F_4t-NeuroP and the plasma amount as individual isomer can be used to discriminate between different brain diseases. Overall, by comparing the different types of disease, our plasma data indicates that 4-F_4t-NeuroP and 10-F_4t -NeuroP: i) are biologically synthesized in vivo and circulated, ii) are related to clinical severity of neurological diseases, iii) are useful to identify shared pathogenetic pathways in distinct brain diseases, and iv) appears to be distinctive for different neurological conditions, thus representing potentially new biological disease markers. Our data strongly suggest that in vivo DHA oxidation follows preferential chemical rearrangements according to different brain diseases.

Individuals with autism have higher 8-Iso-PGF2α levels than controls, but no correlation with quantitative assay of Paraoxonase 1 serum levels

Autism spectrum disorder (ASD) represents a very large set of neurodevelopmental issues with diverse clinical outcomes. Various hypotheses have been put forth for the etiology of autism spectrum disorder, including issues pertaining to oxidative stress. In this study, we conducted measurements of serum 8-Iso-Prostaglanding F2 α (8-iso-PGF2α, which is the results of non-enzimatically mediated polyunsaturated fatty acid oxidation) in a population of individuals with autism and a control group of age and sex matched controls. A quantitative assay of Paraoxonase 1 (PON1) was conducted. Data regarding comorbidities, structural MRI scans, medication, intelligence quotient (IQ) and Childhood Autism Rating Scale scores (CARS) were also included in our study. Our results show that patients diagnosed with autism have higher levels of 8-iso-PGF2α than their neurotypical counterparts. Levels of this particular metabolite, however, do not correlate with quantitative serum levels of Paraoxonase 1, which has been shown to be altered in individuals with autism. Neither 8-iso-PGF2α nor quantitative levels of PON1 provide any meaningful correlation with clinical or neuroimaging data in this study group. Future research should focus on providing data regarding PON 1 phenotype, in addition to standard quantitative measurements, in relation to 8-iso-PGF2α as well as other clinical and structural brain findings.

4-hydroxynonenal protein adducts: Key mediator in Rett syndrome oxinflammation

In the last 15 years a strong correlation between oxidative stress (OxS) and Rett syndrome (RTT), a rare neurodevelopmental disorder known to be caused in 95% of the cases, by a mutation in the methyl-CpG-binding protein 2 (MECP2) gene, has been well documented. Here, we revised, summarized and discussed the current knowledge on the role of lipid peroxidation byproducts, with special emphasis on 4-hydroxynonenal (4HNE), in RTT pathophysiology. The posttranslational modifications of proteins via 4HNE, known as 4HNE protein adducts (4NHE-PAs), causing detrimental effects on protein functions, appear to contribute to the clinical severity of the syndrome, since their levels increase significantly during the subsequent 4 clinical stages, reaching the maximum degree at stage 4, represented by a late motor deterioration. In addition, 4HNE-PA are only partially removed due to the compromised functionality of the proteasome activity, contributing therefore to the cellular damage in RTT. All this will lead to a characteristic subclinical inflammation, defined "OxInflammation", derived by a positive feedback loop between OxS byproducts and inflammatory mediators that in a long run further aggravates the clinical features of RTT patients. Therefore, in a pathology completely orphan of any therapy, aiming 4HNE as a therapeutic target could represent a coadjuvant treatment with some beneficial impact in these patients.‬‬‬.

Omega-3 polyunsaturated fatty acids as a treatment strategy for nonalcoholic fatty liver disease

Obese and type 2 diabetic (T2DM) patients have a high prevalence of nonalcoholic fatty liver disease (NAFLD). NAFLD is a continuum of chronic liver diseases ranging from benign hepatosteatosis to nonalcoholic steatohepatitis (NASH), cirrhosis and primary hepatocellular cancer (HCC). Because of its strong association with the obesity epidemic, NAFLD is rapidly becoming a major public health concern worldwide. Surprisingly, there are no FDA approved NAFLD therapies; and current therapies focus on the co-morbidities associated with NAFLD, namely, obesity, hyperglycemia, dyslipidemia, and hypertension. The goal of this review is to provide background on the disease process, discuss human studies and preclinical models that have examined treatment options. We also provide an in-depth rationale for the use of dietary ω3 polyunsaturated fatty acid (ω3 PUFA) supplements as a treatment option for NAFLD. This focus is based on recent studies indicating that NASH patients and preclinical mouse models of NASH have low levels of hepatic C_20-22 ω3 PUFA. This decline in hepatic PUFA may account for the major phenotypic features associated with NASH, including steatosis, inflammation and fibrosis. Finally, our discussion will address the strengths and limitations of ω3 PUFA supplements use in NAFLD therapy.

Persistent Unresolved Inflammation in the Mecp2-308 Female Mutated Mouse Model of Rett Syndrome

Rett syndrome (RTT) is a rare neurodevelopmental disorder usually caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). Several Mecp2 mutant mouse lines have been developed recapitulating part of the clinical features. In particular, Mecp2-308 female heterozygous mice, bearing a truncating mutation, are a validated model of the disease. While recent data suggest a role for inflammation in RTT, little information on the inflammatory status in murine models of the disease is available. Here, we investigated the inflammatory status by proteomic 2-DE/MALDI-ToF/ToF analyses in symptomatic Mecp2-308 female mice. Ten differentially expressed proteins were evidenced in the Mecp2-308 mutated plasma proteome. In particular, 5 positive acute-phase response (APR) proteins increased (i.e., kininogen-1, alpha-fetoprotein, mannose-binding protein C, alpha-1-antitrypsin, and alpha-2-macroglobulin), and 3 negative APR reactants were decreased (i.e., serotransferrin, albumin, and apolipoprotein A1). CD5 antigen-like and vitamin D-binding protein, two proteins strictly related to inflammation, were also changed. These results indicate for the first time a persistent unresolved inflammation of unknown origin in the Mecp2-308 mouse model.

Red blood cells in Rett syndrome: oxidative stress, morphological changes and altered membrane organization

In this review, we summarize the current evidence on the erythrocyte as a previously unrecognized target cell in Rett syndrome, a rare (1:10 000 females) and devastating neurodevelopmental disorder caused by loss-of-function mutations in a single gene (i.e. MeCP2, CDKL5, or rarely FOXG1). In particular, we focus on morphological changes, membrane oxidative damage, altered membrane fatty acid profile, and aberrant skeletal organization in erythrocytes from patients with typical Rett syndrome and MeCP2 gene mutations. The beneficial effects of ω-3 polyunsaturated fatty acids (PUFAs) are also summarized for this condition to be considered as a 'model' condition for autism spectrum disorders.

Expression and oxidative modifications of plasma proteins in autism spectrum disorders: Interplay between inflammatory response and lipid peroxidation

PURPOSE

A role for inflammation and oxidative stress is reported in autism spectrum disorders (ASDs). Here, we tested possible changes in expression and/or oxidative status for plasma proteins in subjects with ASDs.

EXPERIMENTAL DESIGN

To evaluate protein expression and protein adducts of lipid peroxidation-derived aldehyde, analysis of plasma proteins was performed in 30 subjects with ASDs and compared with 30 healthy controls with typical development, using a proteomic approach.

RESULTS

Significant changes were evidenced for a total of 12 proteins. Of these, ten were identified as proteins involved in the acute inflammatory response including alpha-2-macroglobulin, alpha-1-antitrypsin, haptoglobin, fibrinogen, serum transferrin, prealbumin, apolipoprotein A-I apolipoprotein A-IV, apolipoprotein J, and serum albumin. In addition, significant changes occurred for two immunoglobulins alpha and gamma chains.

CONCLUSIONS AND CLINICAL RELEVANCE

Our present data indicate that an inflammatory response, coupled with increased lipid peroxidation, is present in subjects with ASDs. This information can provide new insight into the identification of potential plasma protein biomarkers in autism.

The Pivotal Role of Aldehyde Toxicity in Autism Spectrum Disorder: The Therapeutic Potential of Micronutrient Supplementation

Autism spectrum disorder (ASD) is characterized by social and communication impairments as well as by restricted, repetitive patterns of behavior and interests. Genomic studies have not revealed dominant genetic errors common to all forms of ASD. So ASD is assumed to be a complex disorder due to mutations in hundreds of common variants. Other theories argue that spontaneous DNA mutations and/or environmental factors contribute to as much as 50% of ASD. In reviewing potential genetic linkages between autism and alcoholism, it became apparent that all theories of ASD are consistent with aldehyde toxicity, in which endogenous and exogenous aldehydes accumulate as a consequence of mutations in key enzymes. Aldehyde toxicity is characterized by cell-localized, micronutrient deficiencies in sulfur-containing antioxidants, thiamine (B1), pyridoxine (B6), folate, Zn²⁺, possibly Mg²⁺, and retinoic acid, causing oxidative stress and a cascade of metabolic disturbances. Aldehydes also react with selective cytosolic and membrane proteins in the cell of origin; then some types migrate to damage neighboring cells. Reactive aldehydes also form adducts with DNA, selectively mutating bases and inducing strand breakage. This article reviews the relevant genomic, biochemical, and nutritional literature, which supports the central hypothesis that most ASD symptoms are consistent with symptoms of aldehyde toxicity. The hypothesis represents a paradigm shift in thinking and has profound implications for clinical detection, treatment, and even prevention of ASD. Insight is offered as to which neurologically afflicted children might successfully be treated with micronutrients and which children are unlikely to be helped. The aldehyde toxicity hypothesis likely applies to other neurological disorders.

The isoprostanes--25 years later

Isoprostanes (IsoPs) are prostaglandin-like molecules generated independent of the cyclooxygenase (COX) by the free radical-induced peroxidation of arachidonic acid. The first isoprostane species discovered were isomeric to prostaglandin F2α and were thus termed F2-IsoPs. Since the initial discovery of the F2-IsoPs, IsoPs with differing ring structures have been identified as well as IsoPs from different polyunsaturated fatty acids, including eicosapentaenoic acid and docosahexanenoic acid. The discovery of these molecules in vivo in humans has been a major contribution to the field of lipid oxidation and free radical research over the course of the past 25 years. These molecules have been determined to be both biomarkers and mediators of oxidative stress in numerous disease settings. This review focuses on recent developments in the field with an emphasis on clinical research. Special focus is given to the use of IsoPs as biomarkers in obesity, ischemia-reperfusion injury, the central nervous system, cancer, and genetic disorders. Additionally, attention is paid to diet and lifestyle factors that can affect endogenous levels of IsoPs. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance."

Altered erythrocyte membrane fatty acid profile in typical Rett syndrome: effects of omega-3 polyunsaturated fatty acid supplementation

This study mainly aims at examining the erythrocyte membrane fatty acid (FAs) profile in Rett syndrome (RTT), a genetically determined neurodevelopmental disease. Early reports suggest a beneficial effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on disease severity in RTT. A total of 24 RTT patients were assigned to ω-3 PUFAs-containing fish oil for 12 months in a randomized controlled study (average DHA and EPA doses of 72.9, and 117.1mg/kgb.w./day, respectively). A distinctly altered FAs profile was detectable in RTT, with deficient ω-6 PUFAs, increased saturated FAs and reduced trans 20:4 FAs. FAs changes were found to be related to redox imbalance, subclinical inflammation, and decreased bone density. Supplementation with ω-3 PUFAs led to improved ω-6/ω-3 ratio and serum plasma lipid profile, decreased PUFAs peroxidation end-products, normalization of biochemical markers of inflammation, and reduction of bone hypodensity as compared to the untreated RTT group. Our data indicate that a significant FAs abnormality is detectable in the RTT erythrocyte membranes and is partially rescued by ω-3 PUFAs.

S-allyl cysteine ameliorates the quality of sperm and provides protection from age-related sperm dysfunction and oxidative stress in rats

Reactive oxygen species play a central role in the pathophysiology of the age-related decrease in male fertility. It has been reported that the total protein of DJ-1 was decreased in a proteomic analysis of seminal plasma from asthenozoospermia patients and a DJ-1 protein acts as a sensor of cellular redox homeostasis. Therefore, we evaluated the age-related changes in the ratio of the oxidized/reduced forms of the DJ-1 protein in the epididymis. In addition, the protective effects of S-allyl cysteine (SAC), a potent antioxidant, were evaluated against sperm dysfunction. Male rats aged 15–75 weeks were used to assess age-associated sperm function and oxidative stress. Sperm count increased until 25 weeks, but then decreased at 50 and 75 weeks. The rate of sperm movement at 75 weeks was decreased to approximately 60% of the rate observed at 25 weeks. Expression of DJ-1 decreased, but oxidized-DJ-1 increased with age. In addition, 4-hydroxy-2-nonenal modified proteins in the epididymis increased until 50 weeks of age. The total number and DNA synthetic potential of the sperm increased until 25 weeks, and then decreased. In rats 75 weeks of age, SAC (0.45% diet) attenuated the decrease in the number, motility, and DNA synthesis of sperm and inhibited the oxidized proteins. These results suggest that SAC ameliorates the quality of sperm subjected to age-associated oxidative stress.

Redox imbalance and morphological changes in skin fibroblasts in typical Rett syndrome

Evidence of oxidative stress has been reported in the blood of patients with Rett syndrome (RTT), a neurodevelopmental disorder mainly caused by mutations in the gene encoding the Methyl-CpG-binding protein 2. Little is known regarding the redox status in RTT cellular systems and its relationship with the morphological phenotype. In RTT patients (n = 16) we investigated four different oxidative stress markers, F2-Isoprostanes (F2-IsoPs), F4-Neuroprostanes (F4-NeuroPs), nonprotein bound iron (NPBI), and (4-HNE PAs), and glutathione in one of the most accessible cells, that is, skin fibroblasts, and searched for possible changes in cellular/intracellular structure and qualitative modifications of synthesized collagen. Significantly increased F4-NeuroPs (12-folds), F2-IsoPs (7.5-folds) NPBI (2.3-folds), 4-HNE PAs (1.48-folds), and GSSG (1.44-folds) were detected, with significantly decreased GSH (-43.6%) and GSH/GSSG ratio (-3.05 folds). A marked dilation of the rough endoplasmic reticulum cisternae, associated with several cytoplasmic multilamellar bodies, was detectable in RTT fibroblasts. Colocalization of collagen I and collagen III, as well as the percentage of type I collagen as derived by semiquantitative immunofluorescence staining analyses, appears to be significantly reduced in RTT cells. Our findings indicate the presence of a redox imbalance and previously unrecognized morphological skin fibroblast abnormalities in RTT patients.

Amyloidosis, inflammation, and oxidative stress in the heart of an alkaptonuric patient

Background. Alkaptonuria, a rare autosomal recessive metabolic disorder caused by deficiency in homogentisate 1,2-dioxygenase activity, leads to accumulation of oxidised homogentisic acid in cartilage and collagenous structures present in all organs and tissues, especially joints and heart, causing a pigmentation called ochronosis. A secondary amyloidosis is associated with AKU. Here we report a study of an aortic valve from an AKU patient. Results. Congo Red birefringence, Th-T fluorescence, and biochemical assays demonstrated the presence of SAA-amyloid deposits in AKU stenotic aortic valve. Light and electron microscopy assessed the colocalization of ochronotic pigment and SAA-amyloid, the presence of calcified areas in the valve. Immunofluorescence detected lipid peroxidation of the tissue and lymphocyte/macrophage infiltration causing inflammation. High SAA plasma levels and proinflammatory cytokines levels comparable to those from rheumatoid arthritis patients were found in AKU patient. Conclusions. SAA-amyloidosis was present in the aortic valve from an AKU patient and colocalized with ochronotic pigment as well as with tissue calcification, lipid oxidation, macrophages infiltration, cell death, and tissue degeneration. A local HGD expression in human cardiac tissue has also been ascertained suggesting a consequent local production of ochronotic pigment in AKU heart.

Oxidative brain damage in Mecp2-mutant murine models of Rett syndrome

Rett syndrome (RTT) is a rare neurodevelopmental disorder affecting almost exclusively females, caused in the overwhelming majority of the cases by loss-of-function mutations in the gene encoding methyl-CpG binding protein 2 (MECP2). High circulating levels of oxidative stress (OS) markers in patients suggest the involvement of OS in the RTT pathogenesis. To investigate the occurrence of oxidative brain damage in Mecp2 mutant mouse models, several OS markers were evaluated in whole brains of Mecp2-null (pre-symptomatic, symptomatic, and rescued) and Mecp2-308 mutated (pre-symptomatic and symptomatic) mice, and compared to those of wild type littermates. Selected OS markers included non-protein-bound iron, isoprostanes (F₂-isoprostanes, F₄-neuroprostanes, F₂-dihomo-isoprostanes) and 4-hydroxy-2-nonenal protein adducts. Our findings indicate that oxidative brain damage 1) occurs in both Mecp2-null (both −/y and stop/y) and Mecp2-308 (both 308/y males and 308/+ females) mouse models of RTT; 2) precedes the onset of symptoms in both Mecp2-null and Mecp2-308 models; and 3) is rescued by Mecp2 brain specific gene reactivation. Our data provide direct evidence of the link between Mecp2 deficiency, oxidative stress and RTT pathology, as demonstrated by the rescue of the brain oxidative homeostasis following brain-specifically Mecp2-reactivated mice. The present study indicates that oxidative brain damage is a previously unrecognized hallmark feature of murine RTT, and suggests that Mecp2 is involved in the protection of the brain from oxidative stress.

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Oxidative damage is demonstrated in the brain, and more specifically in the neurons, of Mecp2 mutant mouse models.

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A direct evidence between enhanced oxidative stress and Mecp2 deficiency is provided.

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Oxidative damage precedes the behavioral abnormalities in Mecp2 mutant mice.

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Mecp2 is likely involved in the protection of the brain from oxidative stress.

Novel molecular approaches for improving enzymatic and nonenzymatic detoxification of 4-hydroxynonenal: toward the discovery of a novel class of bioactive compounds

4-Hydroxy-trans-2-nonenal (HNE), an α,β-unsaturated aldehyde generated endogenously by the radical-mediated peroxidation of ω-6 polyunsaturated fatty acids, is a bioactive molecule acting in several physiopathological mechanisms and most of its activity is due to the covalent modification of biomolecules. Although at low and physiological levels HNE acts as an endogenous signaling molecule, a growing bulk of evidence indicates that at high and toxic concentrations, HNE is involved in the onset and propagation of several human diseases. To get more conclusive evidence of HNE as a pathogenetic factor, a pharmacological tool able to inhibit the HNE-induced cellular response is required. Such compound is currently not available, although several molecular strategies have so far been reported with the aim of inhibiting HNE formation or catalyzing its removal. Although most of these are not selective, such strategies have been found to induce several biological responses and would merit further investigation. In this review the various strategies are reported and discussed together with their limits and potentials.

Effects of ω-3 PUFAs supplementation on myocardial function and oxidative stress markers in typical Rett syndrome

Rett syndrome (RTT) is a devastating neurodevelopmental disorder with a 300-fold increased risk rate for sudden cardiac death. A subclinical myocardial biventricular dysfunction has been recently reported in RTT by our group and found to be associated with an enhanced oxidative stress (OS) status. Here, we tested the effects of the naturally occurring antioxidants ω-3 polyunsaturated fatty acids (ω-3 PUFAs) on echocardiographic parameters and systemic OS markers in a population of RTT patients with the typical clinical form. A total of 66 RTT girls were evaluated, half of whom being treated for 12 months with a dietary supplementation of ω-3 PUFAs at high dosage (docosahexaenoic acid ~71.9 ± 13.9 mg/kg b.w./day plus eicosapentaenoic acid ~115.5 ± 22.4 mg/kg b.w./day) versus the remaining half untreated population. Echocardiographic systolic longitudinal parameters of both ventricles, but not biventricular diastolic measures, improved following ω-3 PUFAs supplementation, with a parallel decrease in the OS markers levels. No significant changes in the examined echocardiographic parameters nor in the OS markers were detectable in the untreated RTT population. Our data indicate that ω-3 PUFAs are able to improve the biventricular myocardial systolic function in RTT and that this functional gain is partially mediated through a regulation of the redox balance.

Subclinical inflammatory status in Rett syndrome

Inflammation has been advocated as a possible common central mechanism for developmental cognitive impairment. Rett syndrome (RTT) is a devastating neurodevelopmental disorder, mainly caused by de novo loss-of-function mutations in the gene encoding MeCP2. Here, we investigated plasma acute phase response (APR) in stage II (i.e., “pseudo-autistic”) RTT patients by routine haematology/clinical chemistry and proteomic 2-DE/MALDI-TOF analyses as a function of four major MECP2 gene mutation types (R306C, T158M, R168X, and large deletions). Elevated erythrocyte sedimentation rate values (median 33.0 mm/h versus 8.0 mm/h, P < 0.0001) were detectable in RTT, whereas C-reactive protein levels were unchanged (P = 0.63). The 2-DE analysis identified significant changes for a total of 17 proteins, the majority of which were categorized as APR proteins, either positive (n = 6 spots) or negative (n = 9 spots), and to a lesser extent as proteins involved in the immune system (n = 2 spots), with some proteins having overlapping functions on metabolism (n = 7 spots). The number of protein changes was proportional to the severity of the mutation. Our findings reveal for the first time the presence of a subclinical chronic inflammatory status related to the “pseudo-autistic” phase of RTT, which is related to the severity carried by the MECP2 gene mutation.

Quantification of functional abilities in Rett syndrome: a comparison between stages III and IV

We aimed to evaluate the functional abilities of persons with Rett syndrome (RTT) in stages III and IV. The group consisted of 60 females who had been diagnosed with RTT: 38 in stage III, mean age (years) of 9.14, with a standard deviation of 5.84 (minimum 2.2/maximum 26.4); and 22 in stage IV, mean age of 12.45, with a standard deviation of 6.17 (minimum 5.3/maximum 26.9). The evaluation was made using the Pediatric Evaluation of Disability Inventory, which has 197 items in the areas of self-care, mobility, and social function. The results showed that in the area of self-care, stage III and stage IV RTT persons had a level of 24.12 and 18.36 (P=0.002), respectively. In the area of mobility, stage III had 37.22 and stage IV had 14.64 (P<0.001), while in the area of social function, stage III had 17.72 and stage IV had 12.14 (P=0.016). In conclusion, although persons with stage III RTT have better functional abilities when compared with stage IV, the areas of mobility, self-care, and social function are quite affected, which shows a great functional dependency and need for help in basic activities of daily life.