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

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

A new version of the Price's algorithm for global optimization

We present an algorithm for finding a global minimum of a multimodal, multivariate functionwhose evaluation is very expensive, affected by noise andwhose derivatives are not available. The proposed algorithm is a new version of the well known Price’s algorithm and its distinguishing feature is that it tries to employ as much as possible the information about the objective function obtained at previous iterates. The algorithm has been tested on a large set of standard test problems and it has shown a satisfactory computational behaviour. The proposed algorithm has been used to solve efficiently some difficult optimization problems deriving from the study of eclipsing binary star light curves

Circulating 4‐f4t‐neuroprostane and 10‐f4t‐neuroprostane are related to mecp2 gene mutation and natural history in rett syndrome

Neuroprostanes, a family of non‐enzymatic metabolites of the docosahexaenoic acid, have been suggested as potential biomarkers for neurological diseases. Objective biological markers are strongly needed in Rett syndrome (RTT), which is a progressive X‐linked neurodevelopmental disorder that is mainly caused by mutations in the methyl‐CpG binding protein 2 (MECP2) gene with a predominant multisystemic phenotype. The aim of the study is to assess a possible association between MECP2 mutations or RTT disease progression and plasma levels of 4(RS)‐4‐F4t-neuroprostane (4‐F4t‐NeuroP) and 10(RS)‐10‐F4t‐neuroprostane (10‐F4t‐NeuroP) in typical RTT patients with proven MECP2 gene mutation. Clinical severity and disease progression were assessed using the Rett clinical severity scale (RCSS) in n = 77 RTT patients. The 4‐F4t‐NeuroP and 10‐F4t‐NeuroP molecules were totally synthesized and used to identify the contents of the plasma of the patients. Neuroprostane levels were related to MECP2 mutation category (i.e., early truncating, gene deletion, late truncating, and missense), specific hotspot mutations (i.e., R106W, R133C, R168X, R255X, R270X, R294X, R306C, and T158M), and disease stage (II through IV). Circulating 4‐F4t‐NeuroP and 10‐F4t‐NeuroP were significantly related to (i) the type of MECP2 mutations where higher levels were associated to gene deletions (p ≤ 0.001); (ii) severity of common hotspot MECP2 mutation (large deletions, R168X, R255X, and R270X); (iii) disease stage, where higher concentrations were observed at stage II (p ≤ 0.002); and (iv) deficiency in walking (p ≤ 0.0003). This study indicates the biological significance of 4‐F4t‐NeuroP and 10‐F4t‐NeuroP as promising molecules to mark the disease progression and potentially gauge genotype–phenotype associations in RTT

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

AbstractIn 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 rarelyFOXG1). 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 andMeCP2gene 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.</jats:p

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

Increased levels of 4HNE-protein plasma adducts in Rett syndrome.

OBJECTIVE: Rett syndrome (RTT) is a neurological disorder and a leading cause of mental retardation in females. It is caused by mutations in methyl-CpG-binding protein 2 (MeCP2) gene and more rarely in cyclin-dependent kinase-like 5 (CDKL5) and forkhead box protein G1 (FOXG1) genes. Increased oxidative stress (OS) has been documented in MeCP2-RTT patients. Here, we evaluated the levels of 4-hydroxynonenal plasma protein adducts (4HNE-PAs) in MeCP2-, CDKL5-, and FOXG1-RTT and in their clinical variants. DESIGN AND METHODS: 4HNE-PAs were determined by Western blot in plasma from healthy subjects and RTT patients. RESULTS: 4HNE-PAs levels were increased in MeCP2- and CDKL5-related RTT but not in FOXG1-related RTT. CONCLUSION: These results showed that OS is present in RTT clinical variants and could play a key role in RTT pathogenesis. Under the OS point of view FOXG1-related RTT appears to be distinct from the MeCP2/CDKL5, suggesting a distinct mechanism involved in its pathogenesis

Unrecognized lung disease in classic Rett syndrome: a physiologic and HRCT study

Background: Breathing disorders in Rett Syndrome (RS) have been generally attributed to severe autonomic and/or brain stem dysfunction, and, to our knowledge, no information regarding lung morphologic characteristics exists to date. The aim of the present study was to determine if there are RS-associated pulmonary abnormalities. Methods: A total of 27 female subjects (age, M ± SD: 12.6 ± 5.9 y; age range: 3-32 y)with geneencoding, methyl-CpG-binding-protein-2-mutation-confirmed RS underwent high-resolution CT (HRCT) scans of the thorax. A volumetric acquisition was used, and isotropic data sets were acquired with thin collimation (&lt; 1-mm slice), scanning through the lungs and processing on a high-spatial-resolution kernel(bony algorithm). Results: Abnormal HRCT scan findings were observed in 15 of 27 (55.5%) cases, consisting of centrilobular nodules (10/15, 66.7%), thickening of the bronchial walls (8/15, 53.33%), and patchy ground-glass opacities (4/15, 26.7%), with upper lobe predominance. In addition, bronchiolectasis were found in nine of 15 (60%) patients. Conclusions: Pulmonary lesions, respiratory bronchiolitis-associated interstitial lung disease-like lesions, are present on imaging studies in about half of typical patients with RS. Further research is needed to clarify the epidemiologic characteristics and the pathogenesis of these previously unrecognized pulmonary abnormalities. © 2010 American College of Chest Physicians