Engineered Hyperactive Integrase for Concerted HIV-1 DNA Integration

The DNA cutting and joining reactions of HIV-1 integration are catalyzed by integrase (IN), a viral protein that functions as a tetramer bridging the two viral DNA ends (intasome). Two major obstacles for biochemical and structural studies of HIV-1 intasomes are 1) the low efficiency of assembly with oligonucleotide DNA substrates, and 2) the non-specific aggregation of both intasomes and free IN in the reaction mixture. By fusing IN with a small non-specific DNA binding protein, Sulfolobus solfataricus chromosomal protein Sso7d (PDB: 1BNZ), we have engineered a highly soluble and hyperactive IN. Unlike wild-type IN, it efficiently catalyzes intasome assembly and concerted integration with oligonucleotide DNA substrates. The fusion IN protein also functions to integrate viral reverse transcripts during HIV-infection. The hyperactive HIV-1 IN may assist in facilitating future biochemical and structural studies of HIV-1 intasomes. Understanding the mechanistic basis of the Sso7d-IN fusion protein could provide insight into the factors that have hindered biophysical studies of wild-type HIV-1 IN and intasomes

Tasco®, a Product of Ascophyllum nodosum, Imparts Thermal Stress Tolerance in Caenorhabditis elegans

Tasco®, a commercial product manufactured from the brown alga Ascophyllum nodosum, has been shown to impart thermal stress tolerance in animals. We investigated the physiological, biochemical and molecular bases of this induced thermal stress tolerance using the invertebrate animal model, Caenorhabiditis elegans. Tasco® water extract (TWE) at 300 μg/mL significantly enhanced thermal stress tolerance as well as extended the life span of C. elegans. The mean survival rate of the model animals under thermal stress (35 °C) treated with 300 μg/mL and 600 μg/mL TWE, respectively, was 68% and 71% higher than the control animals. However, the TWE treatments did not affect the nematode body length, fertility or the cellular localization of daf-16. On the contrary, TWE under thermal stress significantly increased the pharyngeal pumping rate in treated animals compared to the control. Treatment with TWE also showed differential protein expression profiles over control following 2D gel-electrophoresis analysis. Furthermore, TWE significantly altered the expression of at least 40 proteins under thermal stress; among these proteins 34 were up-regulated while six were down-regulated. Mass spectroscopy analysis of the proteins altered by TWE treatment revealed that these proteins were related to heat stress tolerance, energy metabolism and a muscle structure related protein. Among them heat shock proteins, superoxide dismutase, glutathione peroxidase, aldehyde dehydrogenase, saposin-like proteins 20, myosin regulatory light chain 1, cytochrome c oxidase RAS-like, GTP-binding protein RHO A, OS were significantly up-regulated, while eukaryotic translation initiation factor 5A-1 OS, 60S ribosomal protein L18 OS, peroxiredoxin protein 2 were down regulated by TWE treatment. These results were further validated by gene expression and reporter gene expression analyses. Overall results indicate that the water soluble components of Tasco® imparted thermal stress tolerance in the C. elegans by altering stress related biochemical pathways

Tasco®: A Product of Ascophyllum nodosum Enhances Immune Response of Caenorhabditis elegans Against Pseudomonas aeruginosa Infection

The effects of Tasco®, a product made from the brown seaweed (Ascophyllum nodosum) were tested for the ability to protect Caenorhabditis elegans against Pseudomonas aeruginosa infection. A water extract of Tasco® (TWE) reduced P. aeruginosa inflicted mortality in the nematode. The TWE, at a concentration of 300 µg/mL, offered the maximum protection and induced the expression of innate immune response genes viz.; zk6.7 (Lypases), lys-1 (Lysozyme), spp-1 (Saponin like protein), f28d1.3 (Thaumatin like protein), t20g5.7 (Matridin SK domain protein), abf-1 (Antibacterial protein) and f38a1.5 (Lectin family protein). Further, TWE treatment also affected a number of virulence components of the P. aeuroginosa and reduced its secreted virulence factors such as lipase, proteases and toxic metabolites; hydrogen cyanide and pyocyanin. Decreased virulence factors were associated with a significant reduction in expression of regulatory genes involved in quorum sensing, lasI, lasR, rhlI and rhlR. In conclusion, the TWE-treatment protected the C. elegans against P. aeruginosa infection by a combination of effects on the innate immunity of the worms and direct effects on the bacterial quorum sensing and virulence factors

Isolation and anti-HIV-1 integrase activity of lentzeosides A–F from extremotolerant lentzea sp. H45, a strain isolated from a high-altitude Atacama Desert soil

The extremotolerant isolate H45 was one of several actinomycetes isolated from a high-altitude Atacama Desert soil collected in northwest Chile. The isolate was identified as a new Lentzea sp. using a combination of chemotaxonomic, morphological and phylogenetic properties. Large scale fermentation of the strain in two different media followed by chromatographic purification led to the isolation of six new diene and monoene glycosides named lentzeosides A–F, together with the known compound (Z)-3-hexenyl glucoside. The structures of the new compounds were confirmed by HRESIMS and NMR analyses. Compounds 1–6 displayed moderate inhibitory activity against HIV integrase

Structural Basis for Functional Tetramerization of Lentiviral Integrase

Experimental evidence suggests that a tetramer of integrase (IN) is the protagonist of the concerted strand transfer reaction, whereby both ends of retroviral DNA are inserted into a host cell chromosome. Herein we present two crystal structures containing the N-terminal and the catalytic core domains of maedi-visna virus IN in complex with the IN binding domain of the common lentiviral integration co-factor LEDGF. The structures reveal that the dimer-of-dimers architecture of the IN tetramer is stabilized by swapping N-terminal domains between the inner pair of monomers poised to execute catalytic function. Comparison of four independent IN tetramers in our crystal structures elucidate the basis for the closure of the highly flexible dimer-dimer interface, allowing us to model how a pair of active sites become situated for concerted integration. Using a range of complementary approaches, we demonstrate that the dimer-dimer interface is essential for HIV-1 IN tetramerization, concerted integration in vitro, and virus infectivity. Our structures moreover highlight adaptable changes at the interfaces of individual IN dimers that allow divergent lentiviruses to utilize a highly-conserved, common integration co-factor

Capacity shortfalls hinder the performance of marine protected areas globally

Marine protected areas (MPAs) are increasingly being used globally to conserve marine resources. However, whether many MPAs are being effectively and equitably managed, and how MPA management influences substantive outcomes remain unknown. We developed a global database of management and fish population data (433 and 218 MPAs, respectively) to assess: MPA management processes; the effects of MPAs on fish populations; and relationships between management processes and ecological effects. Here we report that many MPAs failed to meet thresholds for effective and equitable management processes, with widespread shortfalls in staff and financial resources. Although 71% of MPAs positively influenced fish populations, these conservation impacts were highly variable. Staff and budget capacity were the strongest predictors of conservation impact: MPAs with adequate staff capacity had ecological effects 2.9 times greater than MPAs with inadequate capacity. Thus, continued global expansion of MPAs without adequate investment in human and financial capacity is likely to lead to sub-optimal conservation outcomes

The impact of trisomy 21 on epidemiology, management, and outcomes of congenital duodenal obstruction: a population-based study

Abstract: Purpose: Congenital duodenal obstruction (CDO) is associated with trisomy 21 (T21), or Down’s syndrome, in around a third of infants. The aim of this study was to explore the impact of T21 on the epidemiology, management, and outcomes of infants with CDO. Methods: Data were prospectively collected from specialist neonatal surgical centres in the United Kingdom over a 12 month period from March 2016 using established population-based methodology for all babies with CDO. Infants with T21 were compared to those without any chromosomal anomaly. Results: Of 102 infants with CDO that underwent operative repair, T21 was present in 33 [32% (95% CI 23–41%)] babies. Cardiac anomalies were more common in those with T21 compared to those without a chromosomal anomaly (91 vs 17%, p < 0.001), whereas associated gastrointestinal anomalies were less common in infants with T21 (3 vs 12%, p = 0.03). Surgical management was not influenced by T21. Time to achieve full enteral feed, need for repeat related surgery, and mortality were similar between groups. Infants with T21 had a longer median initial inpatient stay (23 vs 16.5 days, p = 0.02). Conclusions: Infants with T21 have a higher incidence of cardiac anomalies and a longer initial inpatient stay; however, it does not change CDO management or outcomes. This information is important for prenatal and postnatal counselling of parents of infants with CDO and T21

The impact of trisomy 21 on epidemiology, management, and outcomes of congenital duodenal obstruction: a population-based study

Abstract: Purpose: Congenital duodenal obstruction (CDO) is associated with trisomy 21 (T21), or Down’s syndrome, in around a third of infants. The aim of this study was to explore the impact of T21 on the epidemiology, management, and outcomes of infants with CDO. Methods: Data were prospectively collected from specialist neonatal surgical centres in the United Kingdom over a 12 month period from March 2016 using established population-based methodology for all babies with CDO. Infants with T21 were compared to those without any chromosomal anomaly. Results: Of 102 infants with CDO that underwent operative repair, T21 was present in 33 [32% (95% CI 23–41%)] babies. Cardiac anomalies were more common in those with T21 compared to those without a chromosomal anomaly (91 vs 17%, p < 0.001), whereas associated gastrointestinal anomalies were less common in infants with T21 (3 vs 12%, p = 0.03). Surgical management was not influenced by T21. Time to achieve full enteral feed, need for repeat related surgery, and mortality were similar between groups. Infants with T21 had a longer median initial inpatient stay (23 vs 16.5 days, p = 0.02). Conclusions: Infants with T21 have a higher incidence of cardiac anomalies and a longer initial inpatient stay; however, it does not change CDO management or outcomes. This information is important for prenatal and postnatal counselling of parents of infants with CDO and T21

The feasibility, acceptability and preliminary testing of a novel, low-tech intervention to improve pre-hospital data recording for pre-alert and handover to the Emergency Department

Emergency Department Handover Questionnaire. These are the questions used in the online questionnaire to measure ED staff perceptions of ambulance clinician handover. (PDF 20 kb

Additional file 1: of The feasibility, acceptability and preliminary testing of a novel, low-tech intervention to improve pre-hospital data recording for pre-alert and handover to the Emergency Department

Pre-alert and Handover Card (PAHC). This is the plastic, double sided, pre-alert and handover card issued to Ambulance Clinicians. (PDF 84 kb