Tension as a key factor in skin responses to pollution.

Being the more apparent organ exposed to the outdoor stressors, the effect of pollution on the skin has been widely studied in the last few decades. Although UV light is known as the most aggressive stressor to which our cutaneous tissue is daily exposed, other components of the tropospheric pollution have also shown to affect skin health and functionality. Among them, ozone has been proven to be one of the most toxic due to its high reactivity with the epidermal lipids. Studying the cutaneous effect of pollution in a laboratory setting presents challenges, therefore it becomes critical to employ appropriate and tailored models that aim to answer specific questions. Several skin models are available nowadays: in vitro models (2D cell lines and 3D cutaneous tissues), ex vivo skin explants and in vivo approaches (animals and humans). Although in the last 20 years researchers developed skin models that closely resemble human skin (3D cutaneous tissues), ex vivo skin explants still remain one of the best models to study cutaneous responses. Unfortunately, one important cutaneous property that is not present in the traditional ex vivo human skin explants is the physiological tension, which has been shown to be a cardinal player in skin structure, homeostasis, functional properties and responses to external stimuli. For this reason, in this study, to confirm and further comprehend the harmful mechanism of ozone exposure on the integumentary system, we have performed experiments using the state of art in cutaneous models: the innovative TenSkin™ model in which ex vivo human skin explants are cultured under physiologically relevant tension during the whole experimental procedure. Specifically, we were interested in corroborating previous findings showing that ozone exposure modulates the expression of cutaneous antimicrobial peptides (AMPs). The present work demonstrates that cutaneous exposure to ozone induces AMPs gene and protein levels (CAMP/LL-37, hBD2, hBD3) and that the presence of tension can further modulate their expression. In addition, different responses between tension and non-tension cultured skin were also observed during the evaluation of OxInflammatory markers [cyclooxygenase-2 (COX2), aryl hydrocarbon receptor (AhR), matrix-metallo-proteinase 9 (MMP9) and 4-hydroxy-nonenal (4HNE)]. This current study supports our previous findings confirming the ability of pollution to induce the cutaneous expression of AMPs via redox signaling and corroborates the principle that skin explants are a good and reliable model to study skin responses even though it underlines the need to holistically consider the role of skin tension before extrapolating the data to real life.

Astaxanthin supplementation counters exercise-induced decreases in immune-related plasma proteins.

Objectives: Astaxanthin is a dark red keto-carotenoid found in aquatic animals such as salmon and shrimp, and algae (Haematococcus pluvialis). Astaxanthin has a unique molecular structure that may facilitate anti-oxidative, immunomodulatory, and anti-inflammatory effects during physiological stress. The primary objective of this study was to examine the efficacy of 4-week ingestion of astaxanthin in moderating exercise-induced inflammation and immune dysfunction using a multi-omics approach. Methods: This study employed a randomized, double blind, placebo controlled, crossover design with two 4-week supplementation periods and a 2-week washout period. Study participants were randomized to astaxanthin and placebo trials, with supplements ingested daily for 4 weeks prior to running 2.25 h at close to 70%VO2max (including 30 min of 10% downhill running). After the washout period, participants repeated all procedures using the counterbalanced supplement. The astaxanthin capsule contained 8 mg of algae astaxanthin. Six blood samples were collected before and after supplementation (overnight fasted state), immediately post-exercise, and at 1.5, 3, and 24 h-post-exercise. Plasma aliquots were assayed using untargeted proteomics, and targeted oxylipin and cytokine panels. Results: The 2.25 h running bout induced significant muscle soreness, muscle damage, and inflammation. Astaxanthin supplementation had no effect on exercise-induced muscle soreness, muscle damage, and increases in six plasma cytokines and 42 oxylipins. Notably, astaxanthin supplementation countered exercise-induced decreases in 82 plasma proteins (during 24 h recovery). Biological process analysis revealed that most of these proteins were involved in immune-related functions such as defense responses, complement activation, and humoral immune system responses. Twenty plasma immunoglobulins were identified that differed significantly between the astaxanthin and placebo trials. Plasma levels of IgM decreased significantly post-exercise but recovered after the 24 h post-exercise recovery period in the astaxanthin but not the placebo trial. Discussion: These data support that 4-week astaxanthin versus placebo supplementation did not counter exercise-induced increases in plasma cytokines and oxylipins but was linked to normalization of post-exercise plasma levels of numerous immune-related proteins including immunoglobulins within 24 h. Short-term astaxanthin supplementation (8 mg/day during a 4-week period) provided immune support for runners engaging in a vigorous 2.25 h running bout and uniquely countered decreases in plasma immunoglobulin levels.

Deferoxamine Treatment Improves Antioxidant Cosmeceutical Formulation Protection against Cutaneous Diesel Engine Exhaust Exposure.

Skin is one of the main targets of the outdoor stressors. Considering that pollution levels are rising progressively, it is not surprising that several cutaneous conditions have been associated with its exposure. Among the pollutants, diesel engine exhaust (DEE) represents one of the most toxic, as it is composed of a mixture of many different noxious chemicals generated during the compression cycle, for ignition rather than an electrical spark as in gasoline engines. The toxic chemicals of most concern in DEE, besides the oxides of nitrogen, sulfur dioxide and various hydrocarbons, are metals that can induce oxidative stress and inflammation. The present study aimed to evaluate the effects of topical application, singularly or in combination, of the iron-chelator deferoxamine and a commercially available formulation, CE Ferulic, in up to 4-day DEE-exposed skin. DEE induced a significant increase in the oxidative marker 4-hydroxy-nonenal (4HNE) and matrix-metallopeptidase-9 (MMP-9), the loss of cutaneous-barrier-associated proteins (filaggrin and involucrin) and a decrease in collagen-1, while the formulations prevented the cutaneous damage in an additive manner. In conclusion, this study suggests that iron plays a key role in DEE-induced skin damage and its chelation could be an adjuvant strategy to reinforce antioxidant topical formulations.

Altered Bone Status in Rett Syndrome.

Rett syndrome (RTT) is a monogenic neurodevelopmental disorder primarily caused by mutations in X-linked MECP2 gene, encoding for methyl-CpG binding protein 2 (MeCP2), a multifaceted modulator of gene expression and chromatin organization. Based on the type of mutation, RTT patients exhibit a broad spectrum of clinical phenotypes with various degrees of severity. In addition, as a complex multisystem disease, RTT shows several clinical manifestations ranging from neurological to non-neurological symptoms. The most common non-neurological comorbidities include, among others, orthopedic complications, mainly scoliosis but also early osteopenia/osteoporosis and a high frequency of fractures. A characteristic low bone mineral density dependent on a slow rate of bone formation due to dysfunctional osteoblast activity rather than an increase in bone resorption is at the root of these complications. Evidence from human and animal studies supports the idea that MECP2 mutation could be associated with altered epigenetic regulation of bone-related factors and signaling pathways, including SFRP4/WNT/ß-catenin axis and RANKL/RANK/OPG system. More research is needed to better understand the role of MeCP2 in bone homeostasis. Indeed, uncovering the molecular mechanisms underlying RTT bone problems could reveal new potential pharmacological targets for the treatment of these complications that adversely affect the quality of life of RTT patients for whom the only therapeutic approaches currently available include bisphosphonates, dietary supplements, and physical activity.

Protective effects of a comprehensive topical antioxidant against ozone-induced damage in a reconstructed human skin model.

Tropospheric ozone (O3) is a source of oxidative stress. This study examined the ability of a topical antioxidant (WEL-DS) to inhibit O3-mediated damage in a human epidermal skin model. Four groups of tissues (N = 24) were compared: Group 1 (control) were untreated and unexposed; Group 2 were untreated and exposed to O3 (0.4 ppm, 4 h); Group 3 were pretreated with WEL-DS and unexposed; Group 4 were pretreated with WEL-DS and exposed to O3 (0.4 ppm, 4 h). Pretreated tissues were topically treated with 20 uL of WEL-DS and incubated for up to 20 h at 37 °C [humidified, 5% carbon dioxide (CO2)]. After 24 h, tissues were re-treated with WEL-DS and exposed to O3. Tissues were evaluated for Reactive Oxygen Species (ROS), hydrogen peroxide (H2O2), 4-hydroxynonenal (4-HNE) protein adducts, NF-κB p65 response and histology. In O3-exposed groups, WEL-DS significantly inhibited ROS formation vs. untreated tissues (p < 0.05). Pretreatment with WEL-DS inhibited H2O2 production vs. untreated tissues (p < 0.05), and decreased NF-κB p65 transcription factor signal. Oxidative stress induction in O3-exposed tissues was confirmed by increased levels of 4-HNE protein adducts (marker of lipid peroxidation); WEL-DS application reduced this effect. WEL-DS inhibited damage in tissues exposed to O3 with no significant changes in epidermal structure. A comprehensive topical antioxidant significantly diminished O3-induced oxidative damage in a human epidermal skin model.

Blueberry Extracts as a Novel Approach to Prevent Ozone-Induced Cutaneous Inflammasome Activation.

The World Health Organization estimates that 7 million people die every year due to pollution exposure. Among the different pollutants to which living organism are exposed, ozone (O3) represents one of the most toxic, because its location which is the skin is one of the direct tissues exposed to the outdoor environment. Chronic exposure to outdoor stressors can alter cutaneous redox state resulting in the activation of inflammatory pathways. Recently, a new player in the inflammation mechanism was discovered: the multiprotein complex NLRP1 inflammasome, which has been shown to be also expressed in the skin. The topical application of natural compounds has been studied for the last 40 years as a possible approach to prevent and eventually cure skin conditions. Recently, the possibility to use blueberry (BB) extract to prevent pollution-induced skin toxicity has been of great interest in the cosmeceutical industry. In the present study, we analyzed the cutaneous protective effect of BB extract in several skin models (2D, 3D, and human skin explants). Specifically, we observed that in the different skin models used, BB extracts were able to enhance keratinocyte wound closure and normalize proliferation and migration responses previously altered by O3. In addition, pretreatment with BB extracts was able to prevent ozone-induced ROS production and inflammasome activation measured as NRLP1-ASC scaffold formation and also prevent the transcripts of key inflammasome players such as CASP1 and IL-18, suggesting that this approach as a possible new technology to prevent cutaneous pollution damage. Our data support the hypothesis that BB extracts can effectively reduce skin inflammation and be a possible new technology against cutaneous pollution-induced damage.

Skin Health from the Inside Out.

The skin is the main interface between the body and the environment, providing a biological barrier against an array of chemical and physical pollutants (e.g., ultraviolet light, ozone, etc.). Exposure of the skin to these outdoor stressors generates reactive oxygen species (ROS), which can overwhelm the skin's endogenous defense systems (e.g., catalase, vitamins C and E, etc.), resulting in premature skin aging due to the induction of DNA damage, mitochondrial damage, lipid peroxidation, activation of inflammatory signaling pathways, and formation of protein adducts. In this review, we discuss how topical application of antioxidants, including vitamins C and E, carotenoids, resveratrol, and pycnogenol, can be combined with dietary supplementation of these antioxidant compounds in addition to probiotics and essential minerals to protect against outdoor stressor-induced skin damage, including the damage associated with aging.

Mixed Flavonoid Supplementation Attenuates Postexercise Plasma Levels of 4-Hydroxynonenal and Protein Carbonyls in Endurance Athletes.

This double-blinded, placebo controlled, randomized crossover trial investigated the influence of 2-week mixed flavonoid versus placebo supplementation on oxinflammation markers after a 75-km cycling time trial in 22 cyclists (42.3 ± 1.7 years). Blood samples were collected before and after the 2-week supplementation, and then 0 hr, 1.5 hr, and 21 hr post 75-km cycling (176 ± 5.4 min, 73.4 ±2.0% maximal oxygen consumption). The supplement provided 678-mg flavonoids with quercetin (200 mg), green tea catechins (368 mg, 180-mg epigallocatechin gallate), and anthocyanins (128 mg) from bilberry extract, with caffeine, vitamin C, and omega-3 fatty acids added as adjuvants. Blood samples were analyzed for blood leukocyte counts, oxinflammation biomarkers, including 4-hydroxynonenal, protein carbonyls, and peripheral blood mononuclear mRNA expression for cyclooxygenease-2 and glutathione peroxidase. Each of the blood biomarkers was elevated postexercise (time effects, all ps < .01), with lower plasma levels for 4-hydroxynonenal (at 21-hr postexercise) in flavonoid versus placebo (interaction effect, p = .008). Although elevated postexercise, no trial differences for the neutrophil/lymphocyte ratio (p = .539) or peripheral blood mononuclear mRNA expression for cyclooxygenease-2 (p = .322) or glutathione peroxidase (p = .839) were shown. Flavonoid supplementation prior to intensive exercise decreased plasma peroxidation and oxidative damage, as determined by 4-hydroxynonenal. Postexercise increases were similar between the flavonoid and placebo trials for peripheral blood mononuclear mRNA expression for cyclooxygenease-2 and the nuclear factor erythroid 2-related factor 2 related gene glutathione peroxidase (NFE2L2). The data support the strategy of flavonoid supplementation to mitigate postexercise oxidative stress in endurance athletes.

13-HODE, 9-HODE and ALOX15 as potential players in Rett syndrome OxInflammation.

Mutations in the MECP2 gene are the main cause of Rett syndrome (RTT), a pervasive neurodevelopmental disorder, that shows also multisystem disturbances associated with a metabolic component. The aim of this study was to investigate whether an increased production of oxidized linoleic acid metabolites, specifically 9- and 13-hydroxyoctadecadienoic acids (HODEs), can contribute to the altered the redox and immune homeostasis, suggested to be involved in RTT. Serum levels of 9- and 13-HODEs were elevated in RTT and associated with the expression of arachidonate 15-Lipoxygenase (ALOX15) in peripheral blood mononuclear cells (PBMCs). Omega-3 polyunsaturated fatty acids supplementation has shown to lower HODEs levels in RTT. Statistically significant correlation was demonstrated between the increased plasma HODEs levels and the lipoprotein-associated phospholipase A2 (Lp-PLA2) activity. Collectively, these findings reinforce the concept of the key role played by lipid peroxidation in RTT, and the possible ability of omega-3 polyunsaturated fatty acids supplementation in improving the oxinflammation status in RTT.

Tropospheric ozone affects SRB1 levels via oxidative post-translational modifications in lung cells.

Exposure to air pollution is associated with increased respiratory morbidities and susceptibility to lung dysfunction. Ozone (O3) is commonly recognized as one of the most noxious air pollutant and has been associated with several lung pathologies. It has been demonstrated that decreased lung disorder severity and incidence are connected with the consumption of a diet rich in fruits and vegetables, suggesting that higher intake of dietary micronutrients and phytoactive compounds can be beneficial. However, dietary supplementation - i.e. vitamin E (α-tocopherol) or vitamin A - has not always been effective in improving pulmonary function. Recently, research on the role of nutritional antioxidants on human health has focused more on studying their uptake at the cellular level rather than their effective ability to scavenge reactvive oxygen species (ROS). The Scavenger Receptor B1 (SRB1) has been shown to play a prominent role in the uptake, delivery and regulation of vitamin E in the lung. Given the importance of SRB1 in maintaining lung tissue in a healthy condition, we hypothesize that its expression could be modulated by pollution exposure, which thus could indirectly affect the uptake and/or delivery of lipophilic substances, such as vitamin E. To characterize the molecular mechanism involved in the redox modulation of SRB1, its cellular levels were assessed in human alveolar epithelial cells after O3 exposure. The results demonstrated that O3 induced the loss of SRB1 protein levels. This decline seems to be driven by hydrogen peroxide (H2O2) as a consequence of an increased activation of cellular NADPH oxidase (NOX), as demonstrated by the use of NOX inhibitors or catalase that reversed this effect. Furthermore, O3 caused the formation of SRB1-aldheyde adducts (4-hydroxy-2-nonenal) and the consequent increase of its ubiquitination, a mechanism that could account for SRB1 protein loss.

Potassium Ascorbate with Ribose: Promising Therapeutic Approach for Melanoma Treatment.

While surgery is the definitive treatment for early-stage melanoma, the current therapies against advanced melanoma do not yet provide an effective, long-lasting control of the lesions and a satisfactory impact on patient survival. Thus, research is also focused on novel treatments that could potentiate the current therapies. In the present study, we evaluated the effect of potassium ascorbate with ribose (PAR) treatment on the human melanoma cell line, A375, in 2D and 3D models. In the 2D model, in line with the current literature, the pharmacological treatment with PAR decreased cell proliferation and viability. In addition, an increase in Connexin 43 mRNA and protein was observed. This novel finding was confirmed in PAR-treated melanoma cells cultured in 3D, where an increase in functional gap junctions and a higher spheroid compactness were observed. Moreover, in the 3D model, a remarkable decrease in the size and volume of spheroids was observed, further supporting the treatment efficacy observed in the 2D model. In conclusion, our results suggest that PAR could be used as a safe adjuvant approach in support to conventional therapies for the treatment of melanoma.

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.

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.

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.

Effects of ω-3 polyunsaturated fatty acids on plasma proteome in Rett syndrome.

The mechanism of action of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) is only partially known. Prior reports suggest a partial rescue of clinical symptoms and oxidative stress (OS) alterations following ω -3 PUFAs supplementation in patients with Rett syndrome (RTT), a devastating neurodevelopmental disorder with transient autistic features, affecting almost exclusively females and mainly caused by sporadic mutations in the gene encoding the methyl CpG binding protein 2 (MeCP2) protein. Here, we tested the hypothesis that ω-3 PUFAs may modify the plasma proteome profile in typical RTT patients with MECP2 mutations and classic phenotype. A total of 24 RTT girls at different clinical stages were supplemented with ω-3 PUFAs as fish oil for 12 months and compared to matched healthy controls. The expression of 16 proteins, mainly related to acute phase response (APR), was changed at the baseline in the untreated patients. Following ω-3 PUFAs supplementation, the detected APR was partially rescued, with the expression of 10 out of 16 (62%) proteins being normalized. ω-3 PUFAs have a major impact on the modulation of the APR in RTT, thus providing new insights into the role of inflammation in autistic disorders and paving the way for novel therapeutic strategies.

Partial rescue of Rett syndrome by ω-3 polyunsaturated fatty acids (PUFAs) oil.

Evidence of enhanced oxidative stress (O.S.) and lipid peroxidation has been reported in patients with Rett syndrome (RTT), a relatively rare neurodevelopmental disorder progressing in 4-stages, and mainly caused by loss-of-function mutations in the methyl-CpG-binding protein 2. No effective therapy for preventing or arresting the neurologic regression in the disease in its various clinical presentations is available. Based on our prior evidence of enhanced O.S. and lipid peroxidation in RTT patients, herein we tested the possible therapeutic effects of ω-3 polyunsaturated fatty acids (ω-3 PUFAs), known antioxidants with multiple effects, on the clinical symptoms and O.S. biomarkers in the earliest stage of RTT. A total of 20 patients in stage I were randomized (n = 10 subjects per arm) to either oral supplementation with ω-3 PUFAs-containing fish oil (DHA: 72.9 ± 8.1 mg/kg b.w./day; EPA: 117.1 ± 13.1 mg/kg b.w./day; total ω-3 PUFAs: 246.0 ± 27.5 mg/kg b.w./day) for 6 months or no treatment. Primary outcomes were potential changes in clinical symptoms, with secondary outcomes including variations for five O.S. markers in plasma and/or erythrocytes (nonprotein bound iron, F(2)-dihomo-isoprostanes, F(3)-isoprostanes, F(4)-neuroprostanes, and F(2)-isoprostanes). A significant reduction in the clinical severity (in particular, motor-related signs, nonverbal communication deficits, and breathing abnormalities) together with a significant decrease in all the examined O.S. markers was observed in the ω-3 PUFAs supplemented patients, whereas no significant changes were evidenced in the untreated group. For the first time, these findings strongly suggest that a dietary intervention in this genetic disease at an early stage of its natural history can lead to a partial clinical and biochemical rescue.

Morphological changes and oxidative damage in Rett Syndrome erythrocytes.

BACKGROUND: Hypoxemia and increased oxidative stress (OS) have been reported in Rett Syndrome (RTT), a genetical neurodevelopmental disorder. Although OS and hypoxemia can lead to red blood cells (RBCs) shape abnormalities, no information on RBCs morphology in RTT exists. Here, RBCs shape was evaluated in RTT patients and healthy subjects as a function of OS markers, blood oxygenation, pulmonary gas exchange, and cardio-respiratory parameters. METHODS: RBCs morphology was evaluated by Scanning Electron Microscopy. Intraerythrocyte and plasma non protein-bound iron (NPBI), esterified F(2)-Isoprostanes (F(2)-IsoPs), 4-HNE protein adducts (4-HNE PAs) were measured. Pulmonary oxygen gradients and PaO(2) were evaluated by gas analyzers and cardiopulmonary variables by pulse oximetry. In RTT patients these parameters were assessed before and after ω-3 polyunsaturated fatty acids (ω-3 PUFAs) administration. RESULTS: Altered RBCs shapes (leptocytes) and increased NPBI were present in RTT, together with increased erythrocyte membrane esterified F(2)-IsoPs and 4-HNE PAs. Abnormal erythrocyte shapes were related to OS markers levels, pulmonary gas exchange, PaO(2) and cardio-respiratory variables. After ω-3 PUFAs, a decrease of leptocytes was accompanied by a progressive increase in reversible forms of RBCs. This partial RBCs morphology rescue was related to decreased OS damage markers, improved pulmonary oxygen exchange, and cardiopulmonary physiology. CONCLUSIONS: These findings indicate that in RTT 1) RBCs shape is altered; 2) the OS-hypoxia diad is critical in generating altered RBCs shape and membrane damage; 3) ω-3 PUFAs are able to partially rescue RBCs morphology and the OS-derived damage. GENERAL SIGNIFICANCE: RBCs morphology is an important biosensor for OS imbalance and chronic hypoxemia.

Oxidative stress in Rett syndrome: natural history, genotype, and variants.

OBJECTIVES: Rett syndrome (RTT) is an X-linked autism spectrum disorder caused by mutations in the MeCP2 gene in the great majority of cases. Evidence suggests a potential role of oxidative stress (OS) in its pathogenesis. Here, we investigated the potential value of OS markers (non-protein-bound iron (NPBI) and F2-isoprostanes (F2-IsoPs)) in explaining natural history, genotype-phenotype correlation, and clinical heterogeneity of RTT, and gauging the response to omega-3 polyunsaturated fatty acids (ω-3 PUFAs). METHODS: RTT patients (n=113) and healthy controls were assayed for plasma NPBI and F2-IsoPs, and intraerythrocyte NPBI. Forty-two patients with typical RTT were randomly assigned to ω-3 PUFAs supplementation for 12 months. NPBI was measured by HPLC and F2-IsoPs using a gas chromatography/negative ion chemical ionization tandem mass spectrometry (GC/NICI-MS/MS) technique. RESULTS: F2-IsoPs were significantly higher in the early stages as compared with the late natural progression of classic RTT. MeCP2 mutations related to more severe phenotypes exhibited higher OS marker levels than those of milder phenotypes. Higher OS markers were observed in typical RTT and early seizure variant as compared with the preserved speech and congenital variants. Significant reduction in OS markers levels and improvement of severity scores were observed after ω-3 PUFAs supplementation. DISCUSSION: OS is a key modulator of disease expression in RTT.

F4-neuroprostanes mediate neurological severity in Rett syndrome.

BACKGROUND: Rett syndrome (RTT) is a pervasive development disorder, mainly caused by mutations in the methyl-CpG binding protein 2 (MeCP2) gene. No reliable biochemical markers of the disease are available. Here we assess F4-neuroprostanes (F4-NeuroPs), lipid peroxidation products of the docosahexaenoic acid, as a novel disease marker in RTT and correlate it with clinical presentation, MeCP2 mutation type, and disease progression. In addition, we investigate on the impact of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) supplementation on F4-NeuroPs levels. METHODS: A case-control study design was used. A cohort of RTT patients (n=144) exhibiting different clinical presentations, disease stages, and MeCP2 gene mutations were evaluated. F4-NeuroPs were measured in free form using a GC/NICI-MS/MS technique. Plasma F4-NeuroPs levels in patients were compared to healthy controls and related to RTT forms, disease progression, and response to ω-3 PUFAs supplementation. RESULTS: Plasma F4-NeuroPs levels were i) higher in RTT than in controls; ii) increased with the severity of neurological symptoms; iii) significantly elevated during the typical disease progression; iv) higher in MeCP2-nonsense as compared to missense mutation carriers; v) higher in typical RTT as compared to RTT variants; and vi) decreased in response to 12 months ω-3 PUFAs oral supplementation. CONCLUSIONS: Quantification of plasma F4-NeuroPs provides a novel RTT marker, related to neurological symptoms severity, mutation type and clinical presentation.