DNA damage in lens epithelial cells exposed to occupationally-relevant X-ray doses and role in cataract formation

The current framework of radiological protection of occupational exposed medical workers reduced the eye-lens equivalent dose limit from 150 to 20 mSv per year requiring an accurate dosimetric evaluation and an increase understanding of radiation induced effects on Lens cells considering the typical scenario of occupational exposed medical operators. Indeed, it is widely accepted that genomic damage of Lens epithelial cells (LEC) is a key mechanism of cataractogenesis. However, the relationship between apoptosis and cataractogenesis is still controversial. In this study biological and physical data are combined to improve the understanding of radiation induced effects on LEC. To characterize the occupational exposure of medical workers during angiographic procedures an INNOVA 4100 (General Electric Healthcare) equipment was used (scenario A). Additional experiments were conducted using a research tube (scenario B). For both scenarios, the frequencies of binucleated cells, micronuclei, p21-positive cells were assessed with different doses and dose rates. A Monte-Carlo study was conducted using a model for the photon generation with the X-ray tubes and with the Petri dishes considering the two different scenarios (A and B) to reproduce the experimental conditions and validate the irradiation setups to the cells. The simulation results have been tallied using the Monte Carlo code MCNP6. The spectral characteristics of the different X-ray beams have been estimated. All irradiated samples showed frequencies of micronuclei and p21-positive cells higher than the unirradiated controls. Differences in frequencies increased with the delivered dose measured with Gafchromic films XR-RV3. The spectrum incident on eye lens and Petri, as estimated with MCNP6, was in good agreement in the scenario A (confirming the experimental setup), while the mean energy spectrum was higher in the scenario B. Nevertheless, the response of LEC seemed mainly related to the measured absorbed dose. No effects on viability were detected. Our results support the hypothesis that apoptosis is not responsible for cataract induced by low doses of X-ray (i.e. 25 mGy) while the induction of transient p21 may interfere with the disassembly of the nuclear envelop in differentiating LEC, leading to cataract formation. Further studies are needed to better clarify the relationship we suggested between DNA damage, transient p21 induction and the inability of LEC enucleation

Application of phasor measurement units for monitoring power system dynamic performance

This Working Group is a sequel to a previous working group on Wide Area Monitoring and Control for Transmission Capability Enhancement, which published the Technical Brochure 330 in 2007. Since then the synchrophasor technology has advanced rapidly and many utilities around the world have installed hundreds of PMUs in their networks. In this Technical Brochure, we look at the current state of the technology and the extent to which it has been used in the industry. As the technology has matured, it is also important to understand the communication protocols used in synchrophasor networks and their relevant cyber-security issues. These concerns are briefly discussed in the brochure. The applications of Phasor Measurement Units (PMU) measurements reported here are divided into three categories: (a) applications already installed in utility networks, (b) applications that are well-tested, but not yet installed, and (c) applications that are beneficial to the industry, but not fully developed yet. The most common and mature applications are wide area monitoring, state estimation, and model validation. Out of these three applications, wide area monitoring is well established in the industry. The protection and control applications are emerging as evident from the reported examples. The experience of using remote synchrophasor measurements as feedback control signals is not widely reported by the industry. In parallel to this Working Group, Study Committee B5 had a Working Group on “Wide area protection and control technologies.” The Technical Brochure 664 published by this Working Group in September 2016 reviews synchrophasor technology and discusses the industry experience with wide area protection and control. The North American synchrophasor Initiative (NASPI) is another technical group that has gathered and reported a wide range of PMU experiences of industry and researchers. In summary, the field-tested applications presented in this Technical Brochure are a testimony to the confidence of utilities in the synchrophasor technology. The progress in state estimation techniques indicates that synchrophasor measurements will become a standard part of energy management and security assessment systems in the near future

Targeting Transcription Factor Activity as a Strategy to Inhibit Pro-Inflammatory Genes Involved in Cystic Fibrosis: Decoy Oligonucleotides and Low-Molecular Weight Compounds

The development of drugs able to inhibit the expression of pro-inflammatory genes is of great interest in the treatment of cystic fibrosis (CF). Chronic pulmonary inflammation in the lungs of patients affected by CF is characterized by massive intra-bronchial infiltrates of neutrophils. This process is initiated upon interaction of pathogens (including Pseudomonas aeruginosa) with surface bronchial cells. Consequently, they release cytokines, the most represented being the potent neutrophilic chemokine Interleukin (IL)-8 and the pro-inflammatory cytokine IL-6. The chronic inflammatory process is crucial, since it leads to progressive tissue damage and severe respiratory insufficiency. In order to reduce the adverse effects of the excessive inflammatory response, one of the approaches leading to inhibition of IL-8 and IL-6 gene expression is the transcription factor (TF) decoy approach, based on intracellular delivery of double stranded oligodeoxynucleotides (ODNs) mimicking the binding sites of TFs and causing inhibition of binding of TFrelated proteins to regulatory sequences identified in the promoters of specific genes. Since the promoters of IL-8 and IL-6 contain consensus sequences for NF-κ B and Sp1, double stranded TF "decoy" ODNs targeting NF-κB and Sp1 can be used. Alternatively, screening of drugs targeting relevant TFs can be performed using drug cocktails constituted by extracts from medicinal plants inhibiting TF/DNA interactions. Finally, virtual screening might lead to identification of putative bioactive molecules to be validated using molecular and cellular approaches. By these means, low-molecular drugs targeting NF-κB and inhibiting IL-8 gene expression are available for pre-clinical testing using experimental systems recapitulating chronic pulmonary inflammation of patients affected by CF

Virtual screening against p50 NF-kappaB transcription factor for the identification of inhibitors of the NF-kappaB-DNA interaction and expression of NF-kappaB upregulated genes

Virtual screening against NF-kappaB p50 using docking simulations was applied by starting from a three-dimensional (3D) database containing more than 4.6 million commercially available structures. This database was filtered by specifying a subset of commercially available compounds sharing a (2E,Z)-3-(2-hydroxyphenyl)-2-propenoate substructure and relevant druglike properties. Docking to p50 NF-kappaB was performed with a test set of six known inhibitors of NF-kappaB-DNA interactions. In agreement with docking results, the highest-scored compound displayed a high level of inhibitory activity in electrophoretic mobility shift assay (EMSA) experiments (inhibition of NF-kappaB-DNA interactions) and on biological functions dependent on NF-kappaB activity (inhibition of IL-8 gene expression in cystic fibrosis IB3-1 cells). We found that this in silico screening approach is suitable for the identification of low-molecular-weight compounds that inhibit NF-kappaB-DNA interactions and NF-kappaB-dependent functions. Information deduced from the discovery of the new lead compound and its binding mode could result in further lead optimization resulting in more potent NF-kappaB inhibitors

Red blood cells metabolome changes upon treatment with different X-ray irradiation doses

The upholding of red blood cells (RBC) quality and the removal of leukocytes are two essential issues in transfusion therapy. Leukodepletion provides optimum results, nonetheless there are cases where irradiation is recommended for some groups of hematological patients such as the ones with chronic graft-vs-host disease, congenital cellular immunodeficiency, and hematopoietic stem cell transplant recipients. The European guidelines suggest irradiation doses from 25 to 50 Gray (Gγ). We evaluated the effect of different prescribed doses (15 to 50 Gγ) of X-ray irradiation on fresh leukodepleted RBCs bags using a novel protocol that provides a controlled irradiation. Biochemical assays integrated with RBCs metabolome profile, assessed by nuclear magnetic resonance spectroscopy, were performed on RBC units supernatant, during 14 days storage. Metabolome analysis evidenced a direct correlation between concentration increase of three metabolites, glycine, glutamine and creatine, and irradiation dose. Higher doses (35 and 50 Gγ) effect on RBC mean corpuscular volume, hemolysis, and ammonia concentration are considerable after 7 and 14 days of storage. Our data show that irradiation with 50 Gγ should be avoided and we suggest that 35 Gγ should be the upper limit. Moreover, we suggest for leukodepleted RBCs units the irradiation with the prescribed dose of 15 Gγ, value at center of bag, and ranging between 13.35–15 Gγ, measured over the entire bag volume, may guarantee the same benefits of a 25 Gγ dose assuring, in addition, a better quality of RBCs

COMBINED EFFECTS OF FUROCOUMARIN COMPOUNDS AS ANTI-INFLAMMATORY AND CFTR POTENTIATOR IN CALU-3 EPITHELIAL CELLS

No availabl

Trimethylangelicin Reduces IL-8 Transcription and Potentiates CFTR Function

Chronic inflammatory response in the airway tract of patients affected by cystic fibrosis is characterized by an excessive recruitment of neutrophils to the bronchial lumina, driven by the chemokine Interleukin (IL)-8. We previously found that 5-methoxypsoralen reduces P.aeruginosa-dependent IL-8 transcription in bronchial epithelial cell lines, with an IC(50) of 10 μM. Here, we extended the investigation to analogues of 5-methoxypsoralen and we found that the most potent effect is obtained with 4,6,4'-trimethylangelicin (TMA), which inhibits P.aeruginosa-dependent IL-8 transcription at nanomolar concentration in IB3-1, CuFi-1, CFBE41o- and Calu-3 bronchial epithelial cell lines. Analysis of phosphoproteins involved in proinflammatory transmembrane signaling evidenced that TMA reduces the phosphorylation of RSK1 and AKT2/3, which we found indeed involved in P.aeruginosa-dependent activation of IL-8 gene transcription by testing the effect of pharmacological inhibitors. In addition, we found a docking site of TMA into NF-kB by in silico analysis, whereas inhibition of the NF-kB/DNA interactions in vitro by EMSA was observed at high concentrations (10 mM TMA). In order to further understand whether NF-kB pathway should be considered a target of TMA, Chromatin Immunoprecipitation was performed, and we observed that TMA (100 nM) pre-incubated in whole living cells reduced the interaction of NF-kB with the promoter of IL-8 gene. These results suggest that TMA could inhibit IL-8 gene transcription mainly by intervening on driving the recruitment of activated transcription factors on IL-8 gene promoter, as demonstrated here for NF-kB. Although the complete understanding of the mechanism of action of TMA deserves further investigation, an activity of TMA on phosphorylating pathways was already demonstrated by our study. Finally, since psoralens have been shown to potentiate CFTR-mediated chloride transport, TMA was tested and found to potentiate CFTR-dependent chloride efflux. In conclusion, TMA is a dual-acting compound reducing excessive IL-8 expression and potentiating CFTR function