T cell activation induces CuZn superoxide dismutase (SOD)-1 intracellular re-localization,production and secretion

Reactive oxygen species (ROS) behave as second messengers in signal transduction for a series of receptor/ligand interactions. A major regulatory role is played by hydrogen peroxide (H₂O₂), more stable and able to freely diffuse through cell membranes. Copper–zinc superoxide dismutase (CuZn-SOD)-1 is a cytosolic enzyme involved in scavenging oxygen radicals to H₂O₂ and molecular oxygen, thus representing a major cytosolic source of peroxides. Previous studies suggested that superoxide anion and H₂O₂ generation are involved in T cell receptor (TCR)-dependent signaling. Here, we describe that antigen-dependent activation of human T lymphocytes significantly increased extracellular SOD-1 levels in lymphocyte cultures. This effect was accompanied by the synthesis of SOD-1-specific mRNA and by the induction of microvesicle SOD-1 secretion. It is of note that SOD-1 increased its concentration specifically in T cell population, while no significant changes were observed in the “non-T” cell counterpart. Moreover, confocal microscopy showed that antigen-dependent activation was able to modify SOD-1 intracellular localization in T cells. Indeed, was observed a clear SOD-1 recruitment by TCR clusters. The ROS scavenger N-acetylcysteine (NAC) inhibited this phenomenon. Further studies are needed to define whether SOD-1-dependent superoxide/peroxide balance is relevant for regulation of T cell activation, as well as in the functional cross talk between immune effectors.     

P2X7: a receptor with a split personality that raises new hopes for anti-cancer therapy

Purinergic Signalling -     

Excitability of the Motor Cortex in De Novo Patients with Celiac Disease

Introduction

Celiac disease (CD) may initially present as a neurological disorder or may be complicated by neurological changes. To date, neurophysiological studies aiming to an objective evaluation of the potential central nervous system involvement in CD are lacking.

Objective

To assess the profile of cortical excitability to Transcranial Magnetic Stimulation (TMS) in a group of de novo CD patients.

Materials and methods

Twenty CD patients underwent a screening for cognitive and neuropsychiatric symptoms by means of the Mini Mental State Examination and the Structured Clinical Interview for DSM-IV Axis I Disorders, respectively. Instrumental exams, including electroencephalography and brain computed tomography, were also performed. Cortico-spinal excitability was assessed by means of single and paired-pulse TMS using the first dorsal interosseus muscle of the dominant hand. TMS measures consisted of resting motor threshold, motor evoked potentials, cortical silent period (CSP), intracortical inhibition (ICI) and facilitation (ICF). None of the CD was on gluten-free diet. A group of 20 age-matched healthy controls was used for comparisons.

Results

CD showed a significantly shorter CSP (78.0 vs 125.0 ms, p<0.025), a reduced ICI (0.3 vs 0.2, p<0.045) and an enhanced ICF (1.1 vs 0.7, p<0.042) compared to controls. A dysthymic disorder was identified in five patients. The effect size between dysthymic and non-dysthymic CD patients indicated a low probability of interference with the CSP (Cohen''s d -0.414), ICI (-0.278) and ICF (-0.292) measurements.

Conclusion

A pattern of cortical excitability characterized by “disinhibition” and “hyperfacilitation” was found in CD patients. Immune system dysregulation might play a central role in triggering changes of the motor cortex excitability.     

Polygyny in the tree swallow Tachycineta bicolor: a result of the cost of searching for an unmated male

The costs imposed by parental care duties on an individual's future survival and reproduction generate conflicts because parents should attempt to minimize their investment in the present brood, and exploit the parental care of the other parent. This conflict is likely to contribute to cases of both polygamy and desertion. Here, we study the costs of polygyny in the tree swallow Tachycineta bicolor , using observations on 52 nests that were attended by polygynous males over 14 y. Both females mated to polygynous males paid reproductive costs at several stages of the nesting cycle. Clutches laid by social mates of polygynous versus monogamous males did not differ in size. However, initial brood sizes for polygynously mated females were lower because a higher proportion of their eggs failed to hatch. Likewise, fledging success was lower and nest predation rates were higher, perhaps reflecting the direct or indirect effects of reduced male attention. These results demonstrate that females pay a productivity cost when breeding with reduced male parental care. In contrast, polygynous males fledge on average more young than monogamous ones and clearly benefit from the association. We suggest that a mate-search cost is leading to the few cases of polygamous males: although females are likely evaluating males for their prospective dedication to the breeding attempt, in a short-lived bird with a short breeding season, the cost to females of searching for a more dedicated male is the risk of not breeding at all.     

Chemoselective N-Deacetylation of Protected Nucleosides and Nucleotides Promoted by Schwartz's Reagent

Protection and deprotection strategies involving the N-acetyl group are widely utilized in nucleoside and nucleotide chemistry. Herein, we present a mild and selective N-deacetylation methodology, applicable to purine and pyrimidine nucleosides, by means of Schwartz's reagent, compatible with most of the common protecting groups used in nucleoside chemistry.     

Dual Targeted Therapy with p53 siRNA and Epigallocatechingallate in a Triple Negative Breast Cancer Cell Model

Triple-negative breast cancer (TNBC) is a highly aggressive phenotype that is resistant to standard therapy. Thus, the development of alternative therapeutic strategies for TNBC is essential. The purpose of our in vitro study was to evaluate the impact of p53 gene silencing in conjunction with the administration of a natural compound, epigallocatechingallate (EGCG). RT²Profiler PCR Array technology was used to evaluate the impact of dual treatment on the main genes involved in apoptosis in the Hs578T cell culture model of TNBC. Gene expression analysis revealed 28 genes were significantly altered (16 upregulated and 12 downregulated) in response to combined p53 siRNA and EGCG treatment. Further analysis revealed that p53 siRNA and EGCG dual therapy leads to the activation of pro-apoptotic genes and the inhibition of pro-survival genes, autophagy, and cell network formation. These results indicate that this dual therapy targets both the apoptotic and angiogenic pathways, which may improve treatment effectiveness for tumors resistant to conventional treatment.     

Micronuclei, genetic polymorphisms and cardiovascular disease mortality in a nested case-control study in Italy

AIM: To validate the predictive value of micronuclei (MN) in peripheral blood lymphocytes (PBL) and glutathione-S-transferases (GSTs) polymorphisms (GSTM1 and GSTT1) for mortality risk (MR) of cardiovascular diseases (CVD). METHODS: Blood samples from 1650 healthy subjects selected from the general population were collected between June 1991 and November 1993, and slides were immediately prepared for MN assessment. The vital status, or the cause of death, was monitored for all subjects until January 2005. At the end of the follow-up, 111 deaths were recorded and 39 CVD cases were observed (age range=42-88 years). Two thousand binucleated (BN) cells/subject were scored for the MN assay and GSTs genotypes were assessed on the DNA extracted from the blood or serum samples. RESULTS: A significantly higher MN frequency was recorded for the case group in comparison with the control group (n=67, Kruskall-Wallis test, p=0.006) and GSTT1 null genotype was significantly less frequent in CVD patients (chi(2)-test, p=0.036). The influence of other factors were evaluated using a unconditional logistic regression that confirmed a significant association of GSTT1 positive genotype with an increased OR for CVD (OR=6.29, 95% CI 1.32-29.95) beside a significant effect of age (OR=1.13, 95% CI 1.03-1.26 year(-1)). Finally, subjects with an higher MN frequency showed a higher MR for CVD (Log-rank test, p=0.001). CONCLUSIONS: MN confirmed to be a suitable cytogenetic biomarker for early prediction of CVD death. The GSTT1 positive genotype is associated with an increased MR for CVD.     

High-level HIV-1 Nef transient expression in Nicotiana benthamiana using the P19 gene silencing suppressor protein of Artichoke Mottled Crinckle Virus

Background  

In recent years, different HIV antigens have been successfully expressed in plants by either stable transformation or transient expression systems. Among HIV proteins, Nef is considered a promising target for the formulation of a multi-component vaccine due to its implication in the first steps of viral infection. Attempts to express Nef as a single protein product (not fused to a stabilizing protein) in transgenic plants resulted in disappointingly low yields (about 0.5% of total soluble protein). In this work we describe a transient expression system based on co-agroinfiltration of plant virus gene silencing suppressor proteins in Nicotiana benthamiana, followed by a two-step affinity purification protocol of plant-derived Nef.     

Spatial Distribution of Helicobacter spp. in the Gastrointestinal Tract of Dogs

Background:  In dogs, the gastric Helicobacter spp. have been well studied, but there is little information regarding the other parts of the alimentary system. We sought to determine the spatial distribution of Helicobacter spp. in the gastrointestinal tract and the hepatobiliary system of dogs using culture-independent methods.
Materials and methods:  Samples of stomach, duodenum, ileum, cecum, colon, pancreas, liver, and bile from six dogs were evaluated for Helicobacter spp. by genus, gastric, and enterohepatic Helicobacter spp. Polymerase chain reaction, 16S rRNA gene sequence analysis, immunohistochemistry, and fluorescence in situ hybridization (FISH).
Results:  In the stomach, Helicobacter spp. DNA was detected in all six dogs, with H. bizzozeronii and H. felis identified by specific polymerase chain reaction. Helicobacter organisms were localized within the surface mucus, the lumen of gastric glands, and inside parietal cells. The small intestine harbored gastric and enterohepatic Helicobacter spp. DNA/antigen in low amounts. In the cecum and colon, Helicobacter spp. DNA, with highest similarity to H. bilis /flexispira taxon 8, H. cinaedi , and H. canis, was detected in all six dogs. Helicobacter organisms were localized at the mucosal surface and within the crypts. Gastric Helicobacter spp. DNA was detected occasionally in the large intestine, but no gastric Helicobacter spp. were present in clone libraries or detected by FISH.
Conclusions:  This study demonstrates that in addition to the stomach, the large intestine of dogs is also abundantly colonized by Helicobacter spp. Additional studies are necessary to investigate the association between enterohepatic Helicobacter spp. and presence of intestinal inflammatory or proliferative disorders in dogs.