A Novel Enediynyl Peptide Inhibitor of Furin That Blocks Processing of proPDGF-A, B and proVEGF-C

BACKGROUND: Furin represents a crucial member of secretory mammalian subtilase, the Proprotein Convertase (PC) or Proprotein Convertase Subtilisin/Kexin (PCSK) superfamily. It has been linked to cancer, tumorgenesis, viral and bacterial pathogenesis. As a result it is considered a major target for intervention of these diseases. METHODOLOGY/PRINCIPAL FINDINGS: Herein, we report, for the first time, the synthesis and biological evaluation of a newly designed potent furin inhibitor that contains a highly reactive beta-turn inducing and radical generating "enediynyl amino acid" (Eda) moiety. "Eda" was inserted between P1 and P1' residues of hfurin(98-112) peptide, derived from the primary cleavage site of furin's own prodomain. The resulting hexadecapeptide derivative inhibited furin in vitro with IC(50) approximately 40 nM when measured against the fluorogenic substrate Boc-RVRR-MCA. It also inhibited furin-mediated cleavage of a fluorogenic peptide derived from hSARS-CoV spike protein with IC(50) approximately 193 nM. Additionally it also blocked furin-processing of growth factors proPDGF-A, B and VEGF-C that are linked to tumor genesis and cancer. Circular dichroism study showed that this inhibitor displayed a predominantly beta-turn structure while western blots confirmed its ability to protect furin protein from self degradation. CONCLUSION/SIGNIFICANCE: These findings imply its potential as a therapeutic agent for intervention of cancer and other furin-associated diseases

Feeding mice with diets containing mercury-contaminated fish flesh from French Guiana: a model for the mercurial intoxication of the Wayana Amerindians

International audienc

The cystic fibrosis microbiome in an ecological perspective and its impact in antibiotic therapy

The recent focus on the cystic fibrosis (CF) complex microbiome has led to the recognition that the microbes can interact between them and with the host immune system, affecting the disease progression and treatment routes. Although the main focus remains on the interactions between traditional pathogens, growing evidence supports the contribution and the role of emergent species. Understanding the mechanisms and the biological effects involved in polymicrobial interactions may be the key to improve effective therapies and also to define new strategies for disease control. This review focuses on the interactions between microbe-microbe and host-microbe, from an ecological point of view, discussing their impact on CF disease progression. There are increasing indications that these interactions impact the success of antimicrobial therapy. Consequently, a new approach where therapy is personalized to patients by taking into account their individual CF microbiome is suggested.Portuguese Foundation for Science and Technology (FCT), the strategic funding of UID/BIO/04469/2013-CEB and UID/EQU/00511/2013-LEPABE units. This study was also supported by FCT and the European Community fund FEDER, through Program COMPETE, under the scope of the Projects “DNA mimics” PIC/IC/82815/2007, RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), “BioHealth—Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027 and NORTE-07-0124-FEDER-000025—RL2_ Environment and Health, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. The authors also acknowledge the grant of Susana P. Lopes (SFRH/BPD/95616/2013) and of the COST-Action TD1004: Theragnostics for imaging and therapy

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

14 p.Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

Prioritizing taxa for genetic reference database development to advance inland water conservation

Biodiversity loss has accelerated over the past century and freshwater species overall are among those experiencing greatest declines. Genetic resources have the potential to help evaluate the full magnitude of this loss and represent a key tool to effectively allocate conservation resources and monitor the success of restoration efforts. The full power of genetic resources will be realized when the daunting task of referencing all DNA sequences of freshwater organisms is complete. Here, we quantified the availability and distribution of barcode and genome data for freshwater macroscopic organisms in Canada, a country rich in inland water resources and thus particularly vulnerable to aquatic species losses. Impressively, most inland water species (86 %) were represented by barcodes recorded in the BOLD Systems database, while very few had full genomes available (<4 %) in the NCBI database. We identified barcode data deficiencies in northern regions and for taxa assessed as most at risk or without sufficient information for conservation status classification. As expected, the speciose insect group had a lower-than-average number of records per species and a high proportion of data deficient species without adequate barcode coverage. This study highlights where future sequencing resources should be prioritized within initiatives such as the Canada BioGenome Project and BIOSCAN Canada and provides a workflow that could be applied internationally to inform conservation management plans and to mitigate biodiversity loss

SigB Is a Dominant Regulator of Virulence in <i>Staphylococcus aureus</i> Small-Colony Variants

<div><p><i>Staphylococcus aureus</i> small-colony variants (SCVs) are persistent pathogenic bacteria characterized by slow growth and, for many of these strains, an increased ability to form biofilms and to persist within host cells. The virulence-associated gene expression profile of SCVs clearly differs from that of prototypical strains and is often influenced by SigB rather than by the <i>agr</i> system. One objective of this work was to confirm the role of SigB in the control of the expression of virulence factors involved in biofilm formation and intracellular persistence of SCVs. This study shows that extracellular proteins are involved in the formation of biofilm by three SCV strains, which, additionally, have a low biofilm-dispersing activity. It was determined that SigB activity modulates biofilm formation by strain SCV CF07-S and is dominant over that of the <i>agr</i> system without being solely responsible for the repression of proteolytic activity. On the other hand, the expression of <i>fnbA</i> and the control of nuclease activity contributed to the SigB-dependent formation of biofilm of this SCV strain. SigB was also required for the replication of CF07-S within epithelial cells and may be involved in the colonization of lungs by SCVs in a mouse infection model. This study methodically investigated SigB activity and associated mechanisms in the various aspects of SCV pathogenesis. Results confirm that SigB activity importantly influences the production of virulence factors, biofilm formation and intracellular persistence for some clinical SCV strains.</p></div

Interspecific Small Molecule Interactions between Clinical Isolates of <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i> from Adult Cystic Fibrosis Patients

<div><p><i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i> are the most prevalent pathogens in airway infections of cystic fibrosis (CF) patients. We studied how these pathogens coexist and interact with each other. Clinical isolates of both species were retrieved from adult CF patients. Culture supernatants from 63 <i>P. aeruginosa</i> isolates triggered a wide range of biofilm-stimulatory activities when added to the culture of a control <i>S. aureus</i> strain. The extent of biofilm formation by <i>S. aureus</i> was positively correlated to the levels of the 2-alkyl-4-(1<i>H</i>)-quinolones (AQs) <i>Pseudomonas</i> Quinolone Signal (PQS) and 2-heptyl-4-hydroxy quinoline <i>N</i>-oxide (HQNO) produced by the <i>P. aeruginosa</i> isolates. Supernatants from <i>P. aeruginosa</i> isogenic mutants deficient in PQS and HQNO production stimulated significantly less biofilm formation by <i>S. aureus</i> than that seen with the parental strain PA14. When studying co-isolated pairs of <i>P. aeruginosa</i> and <i>S. aureus</i> retrieved from patients showing both pathogens, <i>P. aeruginosa</i> supernatants stimulated less biofilm production by the <i>S. aureus</i> counterparts compared to that observed using the control <i>S. aureus</i> strain. Accordingly, some <i>P. aeruginosa</i> isolates produced low levels of exoproducts and also some of the clinical <i>S. aureus</i> isolates were not stimulated by their co-isolates or by PA14 despite adequate production of HQNO. This suggests that colonization of the CF lungs promotes some type of strain selection, or that co-existence requires specific adaptations by either or both pathogens. Results provide insights on bacterial interactions in CF.</p></div

SigB is required for the replication of SCV CF07-S within CF cells.

<p>(A) Infection kinetics of shCFTR Calu-3 cells (<i>i.e.</i>, CF-like cells) by strains CF07-L, CF07-S, CF07-SΔ<i>sigB</i> and CF07-SΔ<i>fnbA</i>. Statistically significant differences in CFU/insert recovered from infected cells are indicated (**, <i>P</i><0.01; ***, <i>P</i><0.001 ; ****, <i>P</i><0.0001 ; two-way ANOVA with Bonferonni's posttest, <i>n</i> = 3–7). (B) CFU ratios recovered from cells infected with CF07-L, CF07-S, CF07-SΔ<i>sigB</i> and CF07-SΔ<i>sigB</i> carrying the empty vector (pFM1) or the <i>sigB</i> expression vector (pFM2) 48 h post-invasion. For cells infected with strains carrying a vector, the post-invasion media was supplemented with 0.25 µM CdCl₂. Statistically significant differences between the CFU ratios recovered from cells infected with the different strains are indicated (*, <i>P</i><0.05; ***, <i>P</i><0.001; ANOVA with Tuckey's posttest, <i>n</i> = 3–7). (C) Host cell lysis was evaluated 48 h following invasion with CF07-L, CF07-S and CF07-SΔ<i>sigB</i> by performing LDH cytotoxicity assays. Statistically significant differences are indicated (*, <i>P</i><0.05; **, <i>P</i><0.01; ANOVA with Tuckey's posttest, <i>n</i> = 4). Results are expressed as means with standard deviations.</p

The <i>agr</i> system is influenced by SigB and modulates hemolysis and biofilm formation in SCV CF07-S.

<p>Expression ratio of RNAIII (A) and the <i>hla</i> gene (B) as a function of growth for strains CF07-L, CF07-S, CF07-S in the presence of menadione and CF07-SΔ<i>sigB</i>. Results are expressed according to CF07-L in the early exponential phase of growth. Statistically significant differences to CF07-S are indicated for each growth phase (*, <i>P</i><0.05; **, <i>P</i><0.01; ***, <i>P</i><0.001; ANOVA with Dunnett's posttest, <i>n</i> = 3–6). (C) Hemolytic activity of CF07-L, CF07-S, CF07-SΔ<i>sigB</i> and CF07-SΔ<i>sigB</i> carrying the empty vector (pFM1) or the <i>sigB</i> expression vector (pFM2) following 48 h of incubation on blood-agar plates supplemented with 0.25 µM CdCl₂. (D) Relative biofilm formation of CF07-L, CF07-S and CF07-SΔ<i>sigB</i> carrying the empty vector (pFM1) or the RNAIII expression vector (pFM4) following 48 h of incubation in the presence of 0.12 µM CdCl₂. Statistically significant differences are indicated (ns, non statistically significant; *, <i>P</i><0.05; **, <i>P</i><0.01; ***, <i>P</i><0.001; ANOVA with Tuckey's posttest, <i>n</i> = 3). (E) Expression ratio of the <i>asp23</i> gene for CF07-S carrying the empty vector (pFM1) or the RNAIII expression vector (pFM4) grown to mid-exponential phase in the presence of 0.12 µM CdCl₂. No statistically significant difference was revealed by an unpaired <i>t</i> test (<i>n</i> = 3). Results are expressed as means with standard deviations.</p