Zymosan-mediated inflammation impairs in vivo reverse cholesterol transport

Inflammation has been proposed to impair HDL function and reverse cholesterol transport (RCT). We investigated the effects of inflammation mediated by zymosan, a yeast glucan, on multiple steps along the RCT pathway in vivo and ex vivo. Acute inflammation with 70 mg/kg zymosan impaired RCT to plasma, liver, and feces similarly by 17-22% (P < 0.05), with no additional block at the liver. Hepatic gene expression further demonstrated no change in ABCG5, ABCB4, and ABCB11 expression but a decline in ABCG8 mRNA (32% P < 0.05). Plasma from zymosan-treated mice had a 21% decrease in cholesterol acceptor ability (P < 0.01) and a 35% decrease in ABCA1-specific efflux capacity (P < 0.01) in vitro. Zymosan treatment also decreased HDL levels and led to HDL remodeling with increased incorporation of serum amyloid A. In addition, cholesterol efflux from cultured macrophages declined with zymosan treatment in a dose dependent manner. Taken together, our results suggest that zymosan impairs in vivo RCT primarily by decreasing macrophage-derived cholesterol entering the plasma, with minimal additional blocks downstream. Our study supports the notion that RCT impairment is one of the mechanisms for the increased atherosclerotic burden observed in inflammatory conditions.     

Caveolin-1-eNOS signaling promotes p190RhoGAP-A nitration and endothelial permeability

Endothelial barrier function is regulated by adherens junctions (AJs) and caveolae-mediated transcellular pathways. The opening of AJs that is observed in caveolin-1(-/-) (Cav-1(-/-)) endothelium suggests that Cav-1 is necessary for AJ assembly or maintenance. Here, using endothelial cells isolated from Cav-1(-/-) mice, we show that Cav-1 deficiency induced the activation of endothelial nitric oxide synthase (eNOS) and the generation of nitric oxide (NO) and peroxynitrite. We assessed S-nitrosylation and nitration of AJ-associated proteins to identify downstream NO redox signaling targets. We found that the GTPase-activating protein (GAP) p190RhoGAP-A was selectively nitrated at Tyr1105, resulting in impaired GAP activity and RhoA activation. Inhibition of eNOS or RhoA restored AJ integrity and diminished endothelial hyperpermeability in Cav-1(-/-) mice. Thrombin, a mediator of increased endothelial permeability, also induced nitration of p120-catenin-associated p190RhoGAP-A. Thus, eNOS-dependent nitration of p190RhoGAP-A represents a crucial mechanism for AJ disassembly and resultant increased endothelial permeability.     

Innate immune function of the adherens junction protein p120-catenin in endothelial response to endotoxin

Sepsis-induced acute lung injury is a common clinical disorder in critically ill patients that is associated with high mortality. In this study, we investigated the role of p120-catenin (p120), a constituent of endothelial adherens junctions, in regulating the innate immune function of lungs. In mice in which acute lung injury was induced by i.p. administration of LPS, we observed a rapid decrease in the expression of p120 in lungs. The p120 protein expression was correlated inversely with severity of inflammation. Suppression of p120 expression in lung endothelial cells in mice using small interfering RNA resulted in high sensitivity to endotoxin and greatly increased the mortality compared with controls. Knockdown of p120 also increased the expression of ICAM-1, neutrophil recruitment, production of cytokines TNF-α and IL-6, pulmonary transvascular protein permeability, and lung water content in response to LPS. We demonstrated that endothelial p120 modulates lung innate immune function by interfering with the association of TLR4 with its adaptor MyD88 to block TLR4 signaling and NF-κB activation in endothelial cells. In conclusion, these studies have uncovered a novel innate immune function of endothelial p120 in downregulating the lung inflammatory response to endotoxin through the suppression of TLR4 signaling.     

In vitro haploid and dihaploid production via unfertilized ovule culture

Haploids and doubled haploids are very important in plant breeding, enabling the time needed to produce homozygous lines to be shortened compared with conventional breeding. In the present review, emphasis is given to haploid induction through unfertilized ovule/ovary culture. Attention is given to induction of haploid plants from female gametophyte culture through analysis of factors in the processes of gynogenesis, including genotype selection, stage of ovule development, pretreatment, and culture media containing nutritional components and phytohormones. The gynogenetic approach may be of great value in discovering novel genetic recombinations. Application of double haploids in genetics and plant breeding is also highlighted. This review also identifies some existing knowledge gaps where work may increase the efficiency of this process in different plant species.     

Comparison of the Diversilab® system with multi-locus sequence typing and pulsed-field gel electrophoresis for the characterization of Streptococcus agalactiae invasive strains

Streptococcus agalactiae (or group B streptococcus; GBS) is a leading cause of neonatal morbidity and mortality in the developed countries. Several epidemiological typing tools have been developed for GBS to investigate the association between genotype and disease and to assess genetic variations within genogroups. This study compared the semi-automated repetitive sequence-based PCR Diversilab® system (DL) with MLST and pulsed field gel electrophoresis (PFGE) for determining the relatedness of invasive GBS strains. We analysed 179 unrelated GBS strains isolated from adult (n = 108) and neonatal (n = 71) invasive infections. By MLST, strains were resolved into 6 clonal complexes (CCs) including 23 sequence-types (STs), and 4 unique STs, whereas DL differentiated these isolates into 12 rep-PCR clusters (rPCs) and 9 unique rep-PCR types. The discriminatory power of both methods was similar, with Simpson's diversity indexes of 71.9% and 70.6%, respectively. However, their clustering concordance was low with Wallace concordance coefficients inferior to 0.4. PFGE was performed on 31 isolates representative of the most relevant DLrPCs clustered within the 3 major MLST CCs (CC-17, CC-23 and CC-1). As already observed with MLST, the concordance of DL with PFGE was low for all three CCs (Wallace coefficient < 0.5), PFGE being more discriminative than rep-PCR. In summary, this work suggests that DL is less appropriate than MLST or PFGE to study GBS population genetic diversity.     

New PDE4 inhibitors based on pharmacophoric similarity between papaverine and tofisopam

Pharmacophoric comparison between papaverine and tofisopam led to identify three new series of micro- to sub-micromolar inhibitors of phosphodiesterase-4, including 7,8-dialkoxy-2,3-benzodiazepin-4-one derivatives, 7,8-dialkoxy-1,4-benzodiazepin-2-one derivatives, and dialkoxybenzophenone derivatives.     

Unprecedented C-2 arylation of indole with diazonium salts: Syntheses of 2,3-disubstituted indoles and their antimicrobial activity

A novel reaction of indole with aryldiazonium salts leading to the formation of 2-aryl-3-(arylazo)indoles was discovered. The products were found to possess potent anti-MRSA and anti-LLVRE activities. The SAR studies indicate that the potentially metabolically labile azo functionality can be replaced with ether oxygen and thioether sulfur atoms without any loss of activity.     

Repellent, larvicidal and pupicidal properties of essential oils and their formulations against the housefly, Musca domestica

The essential oils of six plant species [peppermint, Mentha piperita, and bergamot mint, Mentha citrata (both, Lamiales: Lamiaceae); blue gum, Eucalyptus globulus (Myrtales: Myrtaceae); lemongrass, Cymbopogon citratus, and khus grass, Vetiver zizanoides (both, Poales: Poaceae), and turmeric, Curcuma longa (Ziniberales: Zingiberaceae)] were screened for repellent, larvicidal and pupicidal activities against the housefly, Musca domestica L. (Diptera: Muscidae). Subsequently, emulsifiable concentrate (EC) formulations of the two most effective oils were prepared and tested in the laboratory as well as in the field. In repellency bioassays, M. piperita (RC(84) , 61.0 μg/cm(2) ) was found to be most effective, followed by E. globulus (RC(84) , 214.5 μg/cm(2) ) and C. citratus (RC(84) , 289.2 μg/cm(2) ). Formulated M. piperita and E. globulus showed RC(84) values of 1.6 μg/cm(2) and 4.1 μg/cm(2) , respectively. Formulated M. piperita and E. globulus achieved larval mortality (LC(50) ) in 72 h at 5.12 μg/cm(2) and 6.09 μg/cm(2) , respectively. In pupicidal bioassays, crude oils of M. piperita and E. globulus suppressed the emergence of adult flies by 100%. Field experiments with the M. piperita formulation showed reductions in fly density (number of flies/h) of 96% on treated cattle and 98% on treated plots. This study demonstrates the effectiveness of EC formulations of selected essential oils in reducing housefly populations in field conditions.