Polybrominated diphenyl ethers in marine species from the Belgian North Sea and the Western Scheldt Estuary: levels, profiles, and distribution

The Western Scheldt Estuary (SE) is subjected to a variety of suspected PBDE sources, such as a brominated flame retardant manufacturing plant, the Antwerp harbor, and the textile industry located further upstream the river. The Belgian North Sea (BNS) was included in this study to analyze the influence of the SE on the levels found in biota from the BNS locations. Benthic invertebrates, such as shrimp, crab, and starfish, benthic fish, such as goby, dab, plaice, and sole, and gadoid fish, such as bib and whiting, were sampled in the BNS (nonpolluted area) and the SE (polluted area) and analyzed to determine the concentrations and spatial variation of eight polybrominated diphenyl ethers (PBDEs 28, 47, 99, 100, 153, 154, 183, and 209). Levels found in the SE samples were up to 30 times higher than those found in BNS samples, with a gradient increasing toward Antwerp. Levels in BNS ranged from 0.02 to 1.5 ng/g ww in benthic invertebrates and goby, from 0.06 to 0.94 ng/g ww in fish muscle, and from 0.84 to 128 ng/g ww in fish liver. For the SE samples, levels ranged from 0.20 to 29.9 ng/g ww in benthic invertebrates and goby, from 0.08 to 6.9 ng/g ww in fish muscle, and from 15.0 to 984 ng/g ww in fish liver. BDE 209 could only be detected in eight liver samples from the SE and levels ranged between 3.4 and 37.2 ng/g ww. PBDE profiles of the various species at the different locations were compared. Differences in profile were attributed to different exposure and to differences in metabolism among species. Ratios between EDE 99 and 100 were found to be highly location and species dependent, which could be related to differences in metabolism. Some species, such as dab, plaice bib, and whiting, showed preferential accumulation of PBDEs in the liver. Higher brominated congeners in general showed higher affinity for liver than for muscle tissue

PBDEs in marine and freshwater sediments from Belgium: levels, profiles and relations with biota

Sediments from the Belgian North Sea (BNS), the Western Scheldt Estuary (SE) and freshwater watercourses from the Scheldt basin were analysed for eight PBDE congeners, namely BDEs 28, 47, 99, 100, 153, 154, 183 and 209. Previously analysed biological samples from the same locations in the BNS and the SE have been shown to contain large amounts of PBDEs. Surprisingly, PBDE concentrations in the sediments were below the LOQ for samples from the BNS (except BDE 209), while in those from the SE the sum of PBDEs (not including BDE 209) were higher and ranged from 0.20 to 0.41 ng g-1 dw. BDE 209 could be detected in 83% of the samples from the BNS and in all the samples from the SE. Concentrations up to 1200 ng g-1 were hereby measured in the SE. Compared to the marine and estuarine locations, the sediments from the freshwater watercourses were relatively more polluted with the lower brominated PBDEs (-1 dw). BDE 209 concentrations up to 320 ng g-1 dw were measured in those sediments. However, the contribution of BDE 209 to the total amount of PBDEs varied much more at the freshwater locations than in the SE, which suggests a different input of pollutants. PBDE profiles observed in biological samples do not match the profiles of the sediments. BDE 183 and 209 could not be quantified in biota, although these congeners were undoubtedly present in the sediments. This raises questions about the bioavailability of these congeners in the environment

Potent single-domain antibodies that arrest respiratory syncytial virus fusion protein in its prefusion state

Human respiratory syncytial virus (RSV) is the main cause of lower respiratory tract infections in young children. The RSV fusion protein (F) is highly conserved and is the only viral membrane protein that is essential for infection. The prefusion conformation of RSV F is considered the most relevant target for antiviral strategies because it is the fusion-competent form of the protein and the primary target of neutralizing activity present in human serum. Here, we describe two llama-derived single-domain antibodies (VHHs) that have potent RSV-neutralizing activity and bind selectively to prefusion RSV F with picomolar affinity. Crystal structures of these VHHs in complex with prefusion F show that they recognize a conserved cavity formed by two F protomers. In addition, the VHHs prevent RSV replication and lung infiltration of inflammatory monocytes and T cells in RSV-challenged mice. These prefusion F-specific VHHs represent promising antiviral agents against RSV

Surprising findings following a Belgian food contamination with polychlorobiphenyls and dioxins.

We found that 12.1% of Belgian export meat samples from chicken or pork, unrelated to the PCB/dioxin crisis from 1999, contained more than 50 ng polychlorinated biphenyls (PCBs)/g fat and that 6.5% of samples contain more than 20 ng/g fat for the sum of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites. Part of this background contamination stems from imported animal feed ingredients (fish flour and grains), sometimes contaminated by recent use of DDT, as can be deduced from the ratio between DDT and its main metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE). However, after comparing PCB concentrations in fish flour and grains with those found in meat, we suggest that the high concentrations stem from recycled fat. This is the first paper describing background concentrations of PCBs in animal meat from Belgium

Lysozyme-induced transcriptional regulation of tnf-\u3b1 pathway genes in cells of the monocyte lineage

Lysozyme is one of the most important anti-bacterial effectors in the innate immune system of animals. Besides its direct antibacterial enzymatic activity, lysozyme displays other biological properties, pointing toward a significant anti-inflammatory effect, many aspects of which are still elusive. Here we investigate the perturbation of gene expression profiles induced by lysozyme in a monocyte cell line in vitro considering a perspective as broad as the whole transcriptome profiling. The results of the RNA-seq experiment show that lysozyme induces transcriptional modulation of the TNF-\u3b1/IL-1\u3b2 pathway genes in U937 monocytes. The analysis of transcriptomic profiles with IPA\uae identified a simple but robust molecular network of genes, in which the regulation trends are fully consistent with the anti-inflammatory activity of lysozyme. This study provides the first evidence in support of the anti-inflammatory action of lysozyme on the basis of transcriptomic regulation data resulting from the broad perspective of a whole-transcriptome profiling. Such important effects can be achieved with the supplementation of relatively low concentrations of lysozyme, for a short time of exposure. These new insights allow the potential of lysozyme in pharmacological applications to be better exploited

The Arabidopsis PHYTOCHROME KINASE SUBSTRATE2 protein is a phototropin signaling element that regulates leaf flattening and leaf positioning.

In Arabidopsis (Arabidopsis thaliana), the blue light photoreceptor phototropins (phot1 and phot2) fine-tune the photosynthetic status of the plant by controlling several important adaptive processes in response to environmental light variations. These processes include stem and petiole phototropism (leaf positioning), leaf flattening, stomatal opening, and chloroplast movements. The PHYTOCHROME KINASE SUBSTRATE (PKS) protein family comprises four members in Arabidopsis (PKS1-PKS4). PKS1 is a novel phot1 signaling element during phototropism, as it interacts with phot1 and the important signaling element NONPHOTOTROPIC HYPOCOTYL3 (NPH3) and is required for normal phot1-mediated phototropism. In this study, we have analyzed more globally the role of three PKS members (PKS1, PKS2, and PKS4). Systematic analysis of mutants reveals that PKS2 (and to a lesser extent PKS1) act in the same subset of phototropin-controlled responses as NPH3, namely leaf flattening and positioning. PKS1, PKS2, and NPH3 coimmunoprecipitate with both phot1-green fluorescent protein and phot2-green fluorescent protein in leaf extracts. Genetic experiments position PKS2 within phot1 and phot2 pathways controlling leaf positioning and leaf flattening, respectively. NPH3 can act in both phot1 and phot2 pathways, and synergistic interactions observed between pks2 and nph3 mutants suggest complementary roles of PKS2 and NPH3 during phototropin signaling. Finally, several observations further suggest that PKS2 may regulate leaf flattening and positioning by controlling auxin homeostasis. Together with previous findings, our results indicate that the PKS proteins represent an important family of phototropin signaling proteins