Association between SNAP-25 gene polymorphisms and cognition in autism: functional consequences and potential therapeutic strategies

Synaptosomal-associated protein of 25 kDa (SNAP-25) is involved in different neuropsychiatric disorders, including schizophrenia and attention-deficit/hyperactivity disorder. Consistently, SNAP-25 polymorphisms in humans are associated with hyperactivity and/or with low cognitive scores. We analysed five SNAP-25 gene polymorphisms (rs363050, rs363039, rs363043, rs3746544 and rs1051312) in 46 autistic children trying to correlate them with Childhood Autism Rating Scale and electroencephalogram (EEG) abnormalities. The functional effects of rs363050 single-nucleotide polymorphism (SNP) on the gene transcriptional activity, by means of the luciferase reporter gene, were evaluated. To investigate the functional consequences that SNAP-25 reduction may have in children, the behaviour and EEG of SNAP-25(+/-) adolescent mice (SNAP-25(+/+)) were studied. Significant association of SNAP-25 polymorphism with decreasing cognitive scores was observed. Analysis of transcriptional activity revealed that SNP rs363050 encompasses a regulatory element, leading to protein expression decrease. Reduction of SNAP-25 levels in adolescent mice was associated with hyperactivity, cognitive and social impairment and an abnormal EEG, characterized by the occurrence of frequent spikes. Both EEG abnormalities and behavioural deficits were rescued by repeated exposure for 21 days to sodium salt valproate (VLP). A partial recovery of SNAP-25 expression content in SNAP-25(+/-) hippocampi was also observed by means of western blotting. A reduced expression of SNAP-25 is responsible for the cognitive deficits in children affected by autism spectrum disorders, as presumably occurring in the presence of rs363050(G) allele, and for behavioural and EEG alterations in adolescent mice. VLP treatment could result in novel therapeutic strategies.

Effects of natalizumab on oligoclonal bands in the cerebrospinal fluid of multiple sclerosis patients: a longitudinal study

Retrospective studies show that natalizumab modifies oligoclonal immunoglobulin (IgG) bands (OCBs) in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. In this study, we prospectively analyzed both serum and CSF samples from 24 MS patients, before and after 2 years of natalizumab-based therapy. Our results showed complete (55%) or partial (27%) disappearance of the OCBs in CSF samples that were taken after 2 years of therapy. Intrathecal IgG production, represented by the IgG index and IgGLoc, was also quantitatively reduced. Our data showed that natalizumab substantially modulates both intrathecal polyclonal and oligoclonal IgG production: This effect was much more potent than was previously reported.

Individual Thresholding of Voxel-based Functional Connectivity Maps. Estimation of Random Errors by Means of Surrogate Time Series

INTRODUCTION

This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Neural Signals and Images".

BACKGROUND

Voxel-based functional connectivity analysis is a common method for resting state fMRI data. However, correlations between the seed and other brain voxels are corrupted by random estimate errors yielding false connections within the functional connectivity map (FCmap). These errors must be taken into account for a correct interpretation of single-subject results.

OBJECTIVES

We estimated the statistical range of random errors and propose two methods for an individual setting of correlation threshold for FCmaps.

METHODS

We assessed the amount of random errors by means of surrogate time series and described its distribution within the brain. On the basis of these results, the FCmaps of the posterior cingulate cortex (PCC) from 15 healthy subjects were thresholded with two innovative methods: the first one consisted in the computation of a unique (global) threshold value to be applied to all brain voxels, while the second method is to set a different (local) threshold of each voxel of the FCmap.

RESULTS

The distribution of random errors within the brain was observed to be homogeneous and, after thresholding with both methods, the default mode network areas were well identifiable. The two methods yielded similar results, however the application of a global threshold to all brain voxels requires a reduced computational load. The inter-subject variability of the global threshold was observed to be very low and not correlated with age. Global threshold values are also almost independent from the number of surrogates used for their computation, so the analyses can be optimized using a reduced number of surrogate time series.

CONCLUSIONS

We demonstrated the efficacy of FCmaps thresholding based on random error estimation. This method can be used for a reliable single-subject analysis and could also be applied in clinical setting, to compute individual measures of disease progression or quantitative response to pharmacological or rehabilitation treatments.

The Peripheral Network between Oxidative Stress and Inflammation in Multiple Sclerosis

Reactive oxygen species (ROS) are mainly produced by microglia and macrophages during inflammation-driven oxidative burst. However, they can in turn affect the reactivity and function of immune cells. For the first time, the relationship between these two key players involved in Multiple Sclerosis (MS) was evaluated at peripheral level. We performed an in-depth immune-phenotypic and functional analysis of MBP (Myelin Basic Protein)-stimulated Peripheral Blood Mononuclear Cells (PBMCs) by flow-cytometry. In addition, blood Coenzyme-Q10 (CoQ10), total, oxidized and reduced forms of glutathione (GSTot, GSSG, GSH), malondialdehyde (MDA), ROS, anti-oxidized-low-density-lipoproteins antibodies (anti-oxLDL), and anti-oxidant-power (PAO) were studied in 31 untreated MS patients (MSnoTP), 23 MS patients (MSTP) treated with Disease Modifying Drugs (DMDs) and 39 matched controls (HC). The focus of our study was the correlation between oxidative stress biomarkers and distribution of immune-phenotypes across the 3 studied groups. In MSnoTP an inverse correlation between MDA and apoptotic cells (CD4+ AnnexinV+TIM3+) was detected (rs= − 0.50, p= 0.01). Ml functional phenotype (CD14+IL6+) and TH17 cells (CD4+IL22+) inversely (rs= − 0.48) and directly (rs= 0.46) correlated (p = 0.01) with Anti-oxLDL antibodies and GSSG, respectively. The latter direct correlation was shown also in MSTP. Notably, in this group, we also detected a direct correlation between CD4+ IL4+ and CD4+ IL25+ (TH2 phenotype) with CoQ10 (rs= 0.54) and GSH (rs= 0.46) (p< 0.03), two crucial anti-oxidants. Again, a direct correlation was found between CD8+ BDNF+ cells (suppressor phenotype) and anti-oxLDL (rs= 0.48, p= 0.03). Surprisingly, we measured an inverse correlation between CD14+ IL10+ cells (M2 immune-regulatory cells) with GSH (rs= − 0.59, p< 0.001). Our findings endorse the idea of a relationship between pro-inflammatory cells and pro-oxidative environment, even at peripheral level. Interestingly, the correlation between CD4+ IL10+cells and a defective anti-oxidant equipment might be regarded as evidence of the involvement of these cells during an inflammatory/oxidative phase that they try to control. The finding of this link only in MSTP patients might suggest that DMDs can provide an alternative way to counteract inflammation, regardless of an absolute increase of these immune-regulatory cells.

Mec1/ATR regulates the generation of single-stranded DNA that attenuates Tel1/ATM signaling at DNA ends

Tel1/ATM and Mec1/ATR checkpoint kinases are activated by DNA double-strand breaks (DSBs). Mec1/ATR recruitment to DSBs requires the formation of RPA-coated single-stranded DNA (ssDNA), which arises from 5'-3' nucleolytic degradation (resection) of DNA ends. Here, we show that Saccharomyces cerevisiae Mec1 regulates resection of the DSB ends. The lack of Mec1 accelerates resection and reduces the loading to DSBs of the checkpoint protein Rad9, which is known to inhibit ssDNA generation. Extensive resection is instead inhibited by the Mec1-ad mutant variant that increases the recruitment near the DSB of Rad9, which in turn blocks DSB resection by both Rad53-dependent and Rad53-independent mechanisms. The mec1-ad resection defect leads to prolonged persistence at DSBs of the MRX complex that causes unscheduled Tel1 activation, which in turn impairs checkpoint switch off. Thus, Mec1 regulates the generation of ssDNA at DSBs, and this control is important to coordinate Mec1 and Tel1 signaling activities at these breaks.

Gemcitabine (GEM), 5-Fluorouracil (5-FU) and Folinic Acid (FA) in Patients with Different Gastroenteric Malignancies

This phase II clinical trial was performed in order to evaluate the pharmacokinetics, toxicity and anti-tumor activity of a novel combination of gemcitabine (GEM), 5-fluorouracil (5-FU) and folinic acid (FA) designed on a specific translational basis. Every 4 weeks, 44 patients with various gastroenteric malignancies, 29 of whom had pancreas carcinoma, received a short intravenous (i.v.) infusion of FA (100 mg/m2) and 5-FU (400 mg/m2) on days 1-5, and GEM 1000 mg/m2 on days 1, 8 and 16. Our results suggest that, although this treatment leads to hematological and gastroenteric toxicity, it is very active in patients with pancreatic carcinoma. We therefore believe that an improved version would merit further investigation in larger scale trials.

Complete energy conversion by autoresonant three-wave mixing in nonuniform media

Resonant three-wave interactions appear in many fields of physics e.g. nonlinear optics, plasma physics, acoustics and hydrodynamics. A general theory of autoresonant three-wave mixing in a nonuniform media is derived analytically and demonstrated numerically. It is shown that due to the medium nonuniformity, a stable phase-locked evolution is automatically established. For a weak nonuniformity, the efficiency of the energy conversion between the interacting waves can reach almost 100%. One of the potential applications of our theory is the design of highly-efficient optical parametric amplifiers.

Immunomodulating activity of Pidotimod in children with Down syndrome

Acute respiratory tract infections (ARTIs) are the most frequent illnesses in pediatric age, frequently experienced in children with Down Syndrome (DS) due to the associated immune defects of both specific and non-specific immunity. Pidotimod, a synthetic immunostimulant, was shown to reduce the rates of ARTIs in children with DS, however the mechanisms associated with this effect is currently unknown. We analyzed immune parameters in DS children who received the seasonal 2011–2012 virosomal-adjuvanted influenza vaccine. Eighteen children aged 3-10 years (mean age 7.1+/-2.6 years) were randomly assigned (1:1 ratio) to receive Pidotimod 400 mg, administered orally once a day for 90 days or placebo. At the recruitment (T0) all children received a single dose of virosomal-adjuvanted influenza vaccine (Flu). Blood samples were collected at T0 and 3 months after the recruitment (T3) in order to evaluate innate and adaptative immune responses pathway. Flu-specific IgG1 and IgG3 levels in plasma samples were determined at pre-vaccination (T0), and 1 (T1) and 3 months (T3) post-vaccination. The use of Pidotimod was associated with the upregulation of a number of genes involved in the activation of innate immune responses and in antimicrobial activity. Interestingly the ratio of Flu-specific IgG1/IgG3 was skewed in pidotimod-treated individuals, suggesting a preferential activation of complement-dependent effector mechanisms. Although preliminary these data suggest that Pidotimod can potentiate the beneficial effect of immunization, possibly resulting in a stronger activity of both innate and adaptive immune responses.