157 research outputs found
HMGB1-Induced Cross Talk between PTEN and miRs 221/222 in Thyroid Cancer
High mobility group box 1 (HMGB1) is an ubiquitous protein that plays different roles in the nucleus, cytoplasm and extra-cellular space. It is an important DAMP molecule that allows communication between damaged or tumor cells and the immune system. Tumor cells exploit HMGB1’s ability to activate intracellular pathways that lead to cell growth and migration. Papillary thyroid cancer is a well differentiated tumor and is often used to study relationships between cells and the inflammatory microenvironment as the latter is characterized by high levels of inflammatory cells and cytokines. Anaplastic thyroid cancer is one of the most lethal human cancers in which many microRNAs and tumor suppressor genes are de-regulated.
Up-regulation of microRNAs 221 and 222 has been shown to induce the malignant phenotype in many human cancers via inhibition of PTEN expression.
In this study we suggest that extracellular HMGB1 interaction with RAGE enhances expression of oncogenic cluster miR221/222 that in turn inhibits tumor suppressor gene PTEN in two cell lines derived from human thyroid anaplastic and papillary cancers.
The newly identified pathway HMGB1/RAGE/miR 221/222 may represent an effective way of tumor escape from immune surveillance that could be used to develop new therapeutic strategies against anaplastic tumors
Hardware prototyping and validation of a W-ΔDOR digital signal processor
Microwave tracking, usually performed by on ground processing of the signals coming from a spacecraft, represents a crucial aspect in every deep-space mission. Various noise sources, including receiver noise, affect these signals, limiting the accuracy of the radiometric measurements obtained from the radio link. There are several methods used for spacecraft tracking, including the Delta-Differential One-Way Ranging (ΔDOR) technique. In the past years, European Space Agency (ESA) missions relied on a narrowband ΔDOR system for navigation in the cruise phase. To limit the adverse effect of nonlinearities in the receiving chain, an innovative wideband approach to ΔDOR measurements has recently been proposed. This work presents the hardware implementation of a new version of the ESA X/Ka Deep Space Transponder based on the new tracking technique named Wideband ΔDOR (W-ΔDOR). The architecture of the new transponder guarantees backward compatibility with narrowband ΔDOR
MRP4 over-expression has a role on both reducing nitric oxide-dependent antiplatelet effect and enhancing ADP induced platelet activation
The impact of inhibition of multidrug resistance protein 4 (MRP4) on nitric oxide (NO) resistance and on ADP-induced platelet aggregation is unknown. The aim of this investigation was to verify whether platelet NO resistance correlates with MRP4 expression and evaluate whether this can be reduced by in vitro MRP4 inhibition mediated by cilostazol. Moreover, we assessed if inhibition of MRP4-mediated transport reduces ADP-induced platelet reactivity. The inhibitory effect of sodium nitroprusside (SNP), a NO-donor that enhances cyclic guanosine monophosphate (cGMP) cytosolic concentration, was assessed in platelets obtained from aspirin treated patients and in a control population. The inhibitory effect of SNP was evaluated by ADP-induced aggregation in SNP-treated platelets. The impact of MRP4 on ADP-induced platelet aggregation was performed in high on aspirin residual platelet reactivity (HARPR) patients and compared to healthy volunteers (HV), and a control cohort (CTR). In aspirin-treated patients with high levels of MRP4, reduced SNP inhibition was found compared to those with low levels of MRP4. MRP4 inhibition by cilostazol significantly reduced ADP-induced platelet aggregation in HARPR population, and to a lesser extent in HV and CTR populations. In conclusion, cilostazol can mitigate the hyper-reactive platelet phenotype of HARPR patients by reducing residual ADP-induced platelet aggregation and increasing NO-dependent endothelial antiplatelet effects
Organic-Inorganic Hybrid Coatings for Corrosion Protection of Metallic Surfaces
A variety of organic-inorganic hybrids have been designed to act as anticorrosive coatings of metallic substrates. Among them, epoxy-silica and poly(methyl methacrylate) (PMMA)- silica hybrids, prepared by the sol-gel process and deposited onto steel or aluminum alloys, have demonstrated high anticorrosive efficiency combined with high thermal and mechanical resistance. Lignin, carbon nanotubes, and graphene oxide have been incorporated into PMMA-silica hybrids as reinforcement agents, and cerium (IV) as corrosion inhibitor. Both hybrids were characterized in terms of their structural and thermal characteristics using different pectroscopies, microscopies and thermogravimetric analysis. Both hybrids present homogeneous nanostructure composed of highly condensed silica nanodomains covalently bonded to the polymeric phase. The transparent coatings with a thickness of 2–7 μm have low surface roughness, high adhesion to metallic substrates, elevated thermal stability, and excellent barrier behavior. Electrochemical impedance spectroscopy showed for coated samples a high corrosion resistance of up to 50 GΩ cm2 and durability >18 months in saline solution. Further improvement of corrosion resistance, thermal and mechanical stability was achieved by incorporation of lignin, carbon nanotubes, and graphene oxide into PMMA-silica matrix, and a self-healing effect was observed after Ce(IV) addition. The results are compared and discussed with those recently reported for a variety of hybrid coatings
Antiphospholipid antibodies in patients with stroke during COVID-19: A role in the signaling pathway leading to platelet activation
Background: Several viral and bacterial infections, including COVID-19, may lead to both thrombotic and hemorrhagic complications. Previously, it has been demonstrated an "in vitro " pathogenic effect of "antiphospholipid " antibodies (aPLs), which are able to activate a proinflammatory and procoagulant phenotype in monocytes, endothelial cells and platelets. This study analyzed the occurrence of aPL IgG in patients with acute ischemic stroke (AIS) during COVID-19, evaluating the effect of Ig fractions from these patients on signaling and functional activation of platelets. Materials and methods: Sera from 10 patients with AIS during COVID-19, 10 non-COVID-19 stroke patients, 20 COVID-19 and 30 healthy donors (HD) were analyzed for anti-cardiolipin, anti-beta 2-GPI, anti-phosphatidylserine/prothrombin and anti-vimentin/CL antibodies by ELISA. Platelets from healthy donors were incubated with Ig fractions from these patients or with polyclonal anti-beta 2-GPI IgG and analyzed for phospho-ERK and phospho-p38 by western blot. Platelet secretion by ATP release dosage was also evaluated. Results: We demonstrated the presence of aPLs IgG in sera of patients with AIS during COVID-19. Treatment with the Ig fractions from these patients or with polyclonal anti-beta 2-GPI IgG induced a significant increase of phospho-ERK and phospho-p38 expression. In the same vein, platelet activation was supported by the increase of adenyl nucleotides release induced by Ig fractions. Conclusions: This study demonstrates the presence of aPLs in a subgroup of COVID-19 patients who presented AIS, suggesting a role in the mechanisms contributing to hypercoagulable state in these patients. Detecting these antibodies as a serological marker to check and monitor COVID-19 may contribute to improve the risk stratification of thromboembolic manifestations in these patients
Distinct platelet crosstalk with adaptive and innate immune cells after adenoviral and mRNA vaccination against SARS-CoV-2
Background: Genetic-based COVID-19 vaccines have proved highly effective in reducing the risk of hospitalization and death. As they were first distributed on a large-scale population, adenoviral-based vaccines were linked to a very rare thrombosis with thrombocytopenia syndrome and the interplay between platelets and vaccinations increasingly gained attention. Objective: To study the crosstalk between platelets and the vaccine-induced immune response. Methods: We prospectively enrolled young healthy volunteers who received the mRNA-based vaccine, BNT162b2 (n=15), or the adenovirus-based vaccine, AZD1222 (n=25) and studied their short-term platelet and immune response before and after vaccine injections. In a separate cohort, we retrospectively analysed the effect of aspirin on the antibody response 1 and 5 months after BNT162b2 vaccination. Results: Here we show that a faster antibody response to either vaccine is associated to the formation of platelet aggregates with marginal zone-like B-cells, a subset geared to bridge the temporal gap between innate and adaptive immunity. However, while the mRNA-based vaccine is associated with a more gradual and tolerogenic response that fosters the crosstalk between platelets and adaptive immunity, the adenovirus-based vaccine, the less immunogenic of the two, evokes an antiviral-like response during which platelets are cleared and less likely to cooperate with B-cells. Moreover, subjects taking aspirin (n=56) display lower antibody levels after BNT162b2 vaccination compared to matched individuals. Conclusions: Platelets are a component of the innate immune pathways that promote the B-cell response after vaccination. Future studies on the platelet-immune crosstalk post-immunization will improve safety, efficacy, and strategic administration of next-generation vaccines
'Aspirin resistance' or treatment non-compliance: Which is to blame for cardiovascular complications?
Aspirin is one of the 'cornerstone' drugs in our current management of cardiovascular disorders. However, despite the prescription of aspirin recurrent vascular events still occur in 10–20% of patients. These, data together with the observations of diminished antiaggregatory response to aspirin in some subjects have provided the basis of the current debate on the existence of so-called "aspirin resistance". Unfortunately, many of the tests employed to define 'aspirin resistance' lack sufficient sensitivity, specificity, and reproducibility. The prevalence of 'aspirin resistance' as defined by each test varies widely, and furthermore, the value of a single point estimate measure of aspirin resistance is questionable. The rate of 'aspirin resistance' is law if patients observed to ingest aspirin, with large proportion of patients to be pseudo-'aspirin resistant', due to non-compliance. What are the implications for clinical practice? Possible non-adherence to aspirin prescription should also be carefully considered before changing to higher aspirin doses, other antiplatelet drugs (e.g. clopidogrel) or even combination antiplatelet drug therapy. Given the multifactorial nature of atherothrombotic disease, it is not surprising that only about 25% of all cardiovascular complications can usually be prevented by any single medication. We would advocate against routine testing of platelet sensitivity to aspirin (as an attempt to look for 'aspirin resistance') but rather, to highlight the importance of clinicians and public attention to the problem of treatment non-compliance
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