Potent and selective biphenyl azole inhibitors of adipocyte fatty acid binding protein (aFABP)

Herein we report the first disclosure of biphenyl azoles that are nanomolar binders of adipocyte fatty acid binding protein (aFABP or aP2) with up to thousand-fold selectivity against muscle fatty acid binding protein and epidermal fatty acid binding protein. In addition a new radio-ligand to determine binding against the three fatty acid binding proteins was also synthesized.     

Geographic Tools for Eradication Programs of Insular Non-native Mammals

Non-native mammals are major drivers of ecosystem change and biodiversity loss; this is especially apparent on islands. However, techniques exist to remove non-native mammals, providing a powerful conservation tool. Conservation practitioners are now targeting larger islands for restoration. Leveraging existing and developing new techniques and technologies will prove critical to successful eradications on large islands. Using the removal of introduced goats (Capra hircus) from Santiago Island, Galápagos as a case study, we present a suite of Geographic Information System (GIS) tools that aid island conservation actions. GIS tools were incorporated into the three phases of the eradication campaign: planning, hunting, and monitoring. Further, these tools were adopted for three eradication techniques: ground-based hunting, aerial hunting by helicopter, and Judas goats. These geographic approaches provide a foundation for statistical, spatial, and economic analyses that should increase the capability and efficiency of removal campaigns. Given limited conservation funds and the dire status of many insular species, efficiently removing non-native mammals from islands is of paramount global conservation importance.     

Dry reforming of methane with CO2 on an electron-activated iron catalytic bed

A preliminary experimental investigation of dry reforming of methane with carbon dioxide, that has been performed on an iron bed activated with an electric current is reported. Operating conditions for the reaction included temperature ranging from 700 to 800° C and pressure close to 1 atm. The reaction, involving an excess of pure methane and carbon dioxide, was performed with and without addition of water vapour, provided by hot water saturation of the gaseous feed. According to syngas compositions, the electron flow has a dramatic effect on the conversion of both methane and carbon dioxide. It was shown also that hot water saturation of the CO(2) and CH(4) mixture allowed very good conversion, giving a syngas with a composition very close to what was expected from equilibrium calculations.     

EBP2 plays a key role in Epstein-Barr virus mitotic segregation and is regulated by aurora family kinases

Epstein-Barr virus (EBV) genomes persist indefinitely in latently infected human cells, in part due to their ability to stably segregate during cell division. This process is mediated by the viral EBNA1 protein, which tethers the viral episomes to the cellular mitotic chromosomes. We have previously identified a mitotic chromosomal protein, human EBNA1 binding protein 2 (hEBP2), which binds to EBNA1 and enables EBNA1 to partition EBV-based plasmids in Saccharomyces cerevisiae. Using an RNA silencing approach, we show that hEBP2 is essential for the proliferation of human cells and that repression of hEBP2 severely decreases the ability of EBNA1 and EBV-based plasmids to bind mitotic chromosomes. When expressed in yeast, hEBP2 undergoes the same cell cycle-regulated association with the mitotic chromatin as in human cells, and using yeast temperature-sensitive mutant strains, we found that the attachment of hEBP2 to mitotic chromosomes was dependent on the Ipl1 kinase. Both RNA silencing of the Ipl1 orthologue in human cells (Aurora B) and specific inhibition of the Aurora B kinase activity with a small molecule confirmed a role for this kinase in enabling hEBP2 binding to human mitotic chromosomes, suggesting that this kinase can regulate EBV segregation.     

Microarray analysis of regional cellular responses to local mechanical stress in acute lung injury

Human acute lung injury is characterized by heterogeneous tissue involvement, leading to the potential for extremes of mechanical stress and tissue injury when mechanical ventilation, required to support critically ill patients, is employed. Our goal was to establish whether regional cellular responses to these disparate local mechanical conditions could be determined as a novel approach toward understanding the mechanism of development of ventilator-associated lung injury. We utilized cross-species genomic microarrays in a unilateral model of ventilator-associated lung injury in anesthetized dogs to assess regional cellular responses to local mechanical conditions that potentially contribute pathogenic mechanisms of injury. Highly significant regional differences in gene expression were observed between lung apex/base regions as well as between gravitationally dependent/nondependent regions of the base, with 367 and 1,544 genes differentially regulated between these regions, respectively. Major functional groupings of differentially regulated genes included inflammation and immune responses, cell proliferation, adhesion, signaling, and apoptosis. Expression of genes encoding both acute lung injury-associated inflammatory cytokines and protective acute response genes were markedly different in the nondependent compared with the dependent regions of the lung base. We conclude that there are significant differences in the local responses to stress within the lung, and consequently, insights into the cellular responses that contribute to ventilator-associated lung injury development must be sought in the context of the mechanical heterogeneity that characterizes this syndrome.     

Possible role of Efnb1 protein, a ligand of Eph receptor tyrosine kinases, in modulating blood pressure

Eph kinases constitute the largest receptor tyrosine kinase family, and their ligands, ephrins (Efns), are also cell surface molecules. Although they are ligands, Efns can transduce signals reversely into cells. We have no prior knowledge of the role played by any members of this family of kinases or their ligands in blood pressure (BP) regulation. In the present studies, we investigated the role of Efnb1 in vascular smooth muscle cell (VSMC) contractility and BP regulation. We revealed that reverse signaling through Efnb1 led to a reduction of RhoA activation and VSMC contractility in vitro. Consistent with this finding, ex vivo, there was an increase of RhoA activity accompanied by augmented myosin light chain phosphorylation in mesenteric arteries from mice with smooth muscle-specific conditional Efnb1 gene knock-out (KO). Small interfering RNA knockdown of Grip1, a molecule associated with the Efnb1 intracellular tail, partially eliminated the effect of Efnb1 on VSMC contractility and myosin light chain phosphorylation. In support of these in vitro and ex vivo results, Efnb1 KO mice on a high salt diet showed a statistically significant heightened increment of BP at multiple time points during stress compared with wild type littermates. Our results demonstrate that Efnb1 is a previously unknown negative regulator of VSMC contractility and BP and that it exerts such effects via reverse signaling through Grip1.     

RSK phosphorylates SOS1 creating 14-3-3-docking sites and negatively regulating MAPK activation

The extent and duration of MAPK (mitogen-activated protein kinase) signalling govern a diversity of normal and aberrant cellular outcomes. Genetic and pharmacological disruption of the MAPK-activated kinase RSK (ribosomal S6 kinase) leads to elevated MAPK activity indicative of a RSK-dependent negative feedback loop. Using biochemical, pharmacological and quantitative MS approaches we show that RSK phosphorylates the Ras activator SOS1 (Son of Sevenless homologue 1) in cultured cells on two C-terminal residues, Ser1134 and Ser1161. Furthermore, we find that RSK-dependent SOS1 phosphorylation creates 14-3-3-binding sites. We show that mutating Ser1134 and Ser1161 disrupts 14-3-3 binding and modestly increases and extends MAPK activation. Together these data suggest that one mechanism whereby RSK negatively regulates MAPK activation is via site-specific SOS1 phosphorylation.