Inhibition of dengue virus entry and multiplication into monocytes using RNA interference

Background

Dengue infection ranks as one of the most significant viral diseases of the globe. Currently, there is no specific vaccine or antiviral therapy for prevention or treatment. Monocytes/macrophages are the principal target cells for dengue virus and are responsible for disseminating the virus after its transmission. Dengue virus enters target cells via receptor-mediated endocytosis after the viral envelope protein E attaches to the cell surface receptor. This study aimed to investigate the effect of silencing the CD-14 associated molecule and clathrin-mediated endocytosis using siRNA on dengue virus entry into monocytes.

Methodology/Principal Findings

Gene expression analysis showed a significant down-regulation of the target genes (82.7%, 84.9 and 76.3% for CD-14 associated molecule, CLTC and DNM2 respectively) in transfected monocytes. The effect of silencing of target genes on dengue virus entry into monocytes was investigated by infecting silenced and non-silenced monocytes with DENV-2. Results showed a significant reduction of infected cells (85.2%), intracellular viral RNA load (73.0%), and extracellular viral RNA load (63.0%) in silenced monocytes as compared to non-silenced monocytes.

Conclusions/Significance

Silencing the cell surface receptor and clathrin mediated endocytosis using RNA interference resulted in inhibition of the dengue virus entry and subsequently multiplication of the virus in the monocytes. This might serve as a novel promising therapeutic target to attenuate dengue infection and thus reduce transmission as well as progression to severe dengue hemorrhagic fever.     

Bis- and mono-substituted Chalcones exert anti-feedant and toxic effects on fall armyworm Spodoptera frugiperda

Spodoptera frugiperda is a highly polyphagous migratory lepidopteran pest species. It causes infestation in crops leading to the severe crop losses. Being a new invasive parasite, its susceptibility to insecticides needs to be explored; and therefore, there is an urgent need to develop the potent insecticides for the effective control of this insect pest. To attain the crop sustainability, the antifeedant, toxicity and nutritional effects on larvae of Spodoptera frugiperda were studied with six mono- and eight bis- substituted chalcones. The antifeedant activity was calculated when 50% of the larvae control ate 50% of the diet through the FR factor. Toxicity was assessed through larval, pupal mortality and the emergence of adults and nutritional effects with consumption rates (IC), growth (GR) and consumption efficiency (EIC). The bis-chalcones 6b, 6e, 6f and 6h caused lethal effect on S. frugiperda in the first larval stages, being 6b the most toxic (85%). Adults who survived showed malformations and decreased size, which led to death. The larvae fed with aggregate in the bis-chalcones diet: 6b, 6e and 6f had the highest percentage of intake and the poorest conversion of nutrient absorption (ECI), which suggests that the larva metabolizes food for energy and results in a decrease of growth and death in early stages. Bis-chalcones showed more toxicity than mono-chalcones and 6b causes the most toxic and dietary change.     

Morphological and molecular characterization of new plant type core set for yield and culm strength traits in rice (Oryza sativa L.)

New plant type core set comprising indica and tropical japonica accessions along with checks were evaluated for yield and culm strength related traits and characterized with gene specific markers viz., Gn1a, DEP1, Ghd7, SPL14, GS5, TGW6 and SCM2. Analysis of variance revealed significant differences as well as presence of variability among the genotypes for all the traits. Seven genotypes (IRGC25510, IRGC1742, Haorei machang, Azhoghi, Thangmoi, BPT5204 and Swarnadhan) do not possess similar allele as that of the assessed genes based on combined analysis for all the traits and genes. Of them, four genotypes IRGC1742, Azhoghi, BPT5204 and Swarnadhan possess ideal trait combination (90–100 days to 50% flowering, 100–120 cm plant height, grain number of > 200, 11–15 productive tillers) but with weak culm can be ideal sources for identification of new genes for yield attributing traits and direct introgression of SCM2. Based on single trait-gene analysis, nine trait wise donors with high value for the trait (also with desirable plant type) but without similar allele of the corresponding gene were identified. One genotype IRGC7486 with high grain number (300), four genotypes (IRGC50448, IRGC43741, IRGC15147 and IRGC39111) with strong culm (1195–2655 g.f), three genotypes viz., IRGC15147, IRGC39111 and IRGC10658 with high panicle weight and one genotype Solumpiket with high 1000-grain weight and high panicle weight can be considered for identification of novel gene(s) for respective traits.

     

In Vitro Assessment of Probiotic Potential of an Autochthonous Bacterial Isolate,Pseudomonas mosselii COFCAU_PMP5

Microbiology - Microbiota of the fish gut contains many beneficial bacteria that can be used as probiotics in aquaculture. In this study, several in vitro assays along with an in vivo safety...     

Efficacy of some biorational insecticides against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) under laboratory and greenhouse conditions in Kuwait

The tomato leafminer, Tuta absoluta, is one of the most destructive pests of tomato worldwide. Management of the pest is mainly based on chemical insecticides. Reliance on insecticides is difficult to sustain because of unintended long‐term adverse effects on the environment and human health. Consequently, there is a need to develop pest management strategies that ensure the production of high‐quality products, while at the same time ensuring environmental sustainability and maximum consumer protection. We evaluated the efficacy the biopesticides: Azadirachtin, Bacillus thuringiensis, Steinernema feltiae and Beauveria bassiana individually and in combination against T. absoluta under laboratory and greenhouse conditions. When second instar larvae were exposed to tomato leaf discs treated with Azadirachtin (3 g / L), B. thuringiensis (0.5 g/L) or B. bassiana (1.5 g/L), 70%–86%, 55%–65%, and 45.5%–58.5% mortality was observed, respectively. Steinernema feltiae (1,000 IJs/ml) was the least effective biopesticide, with 26%–42% mortality. In the greenhouse trials on tomato, pest infestation (mines/10 leaves/plant) and fruits damaged were significantly lower on plants treated with Azadirachtin  +  B. thuringiensis or Azadirachtin  +  B. bassiana compared to plants treated with Azadirachtin, B. thuringiensi, B. bassiana or S. feltiae alone. Azadirachtin  +  B. thuringiensis and Azadirachtin  +  B. bassiana resulted in 90% and 81% reduction in fruits damaged in the summer experiments, respectively, and 96% and 91% in winter. The most severe pest infestation was observed on plants treated with S. feltia. The results indicate that the biopesticides, except S. feltia, can contribute to T. absoluta control in greenhouse tomato crops. In particular, the combined use of Azadirachtin with B. thuringiensis or B. bassiana provided the highest level of control of the pest. The potential for including these biopesticides in an overall sustainable integrated pest management programme for T. absoluta is discussed.     

Synthesis,biological evaluation and molecular docking study of 1-amino-2-aroylnaphthalenes against prostate cancer

A series of functionalized naphthalene was synthesized and screened against human prostate cancer cell line (PC-3). The in vitro antiproliferative activity of the synthesized compounds was evaluated by monitoring their cytotoxic effects against PC-3 cells by using MTT assay. We observed that compound 5f resulted in more than 50% cell death at 14?µM. Treatment of PC-3 cells with 5f provides apoptosis by flow cytometry. Western blotting showed decreased expression of pro-caspase 8 and 9. Our study shows that cancer cell treated with 5f has higher concentration of reactive oxygen species as compare to untreated sample, which facilitate cancerous cell to enter apoptosis. Exact mechanism by which ROS is generated after 5f treatment is still under study. Molecular docking study further strengthens the results obtained from in vitro experiments. Compound 5f can be considered as a promising leads for anticancer agent against prostate cancer cells due to its potent cytotoxic activity and apoptotic effect.     

Chemical egg defence in the large milkweed bug,Oncopeltus fasciatus,derives from maternal but not paternal diet

Many herbivorous insects sequester defensive compounds from their host‐plants and incorporate them into their eggs to protect them against predation. Here, we investigate whether transmission of cardenolides from the host‐diet to the eggs is maternal, paternal, or biparental in the large milkweed bug, Oncopeltus fasciatus (Dallas) (Hemiptera: Lygaeidae). We reared individual bugs on either milkweed seeds [MW; Asclepias syriaca L. (Apocynaceae)] that contain cardenolides, or on sunflower seeds [SF; Helianthus annuus L. (Asteraceae)] that do not contain cardenolides. We mated females and males so that all four maternal/paternal diet combinations were represented: MW/MW, MW/SF, SF/MW, and SF/SF. Using larvae of the common green lacewing, Chrysoperla (Chrysopa) carnea (Stevens) (Neuroptera: Chrysopidae), we conducted two‐choice predation trials to assess whether maternal, paternal, or biparental transmission of cardenolides into the eggs of O. fasciatus increased protection against predation. Furthermore, we used high performance liquid chromatography (HPLC) to assess putative cardenolide content of eggs from the various parental diet treatment groups. The predation trials suggested that regardless of male diet, eggs were afforded better protection when females had been raised on milkweed. However, many eggs were at least partially consumed. This suggests that although chemical defence of eggs does not guarantee protection to eggs on an individual basis, they may increase the probability that some eggs in a clutch are left intact thereby potentially conferring a fitness advantage to more offspring than if eggs are left unprotected. Based on HPLC analysis we found that maternal contribution of cardenolides was significantly greater than paternal contribution of cardenolides to the eggs, supporting the results of our predation trials that a maternal diet of milkweed makes eggs more distasteful than a paternal diet of milkweed.     

Outcomes of decades long installation of nest boxes for arboreal mammals in southern Australia

Nest boxes are commonly installed to support hollow‐using species where the abundance of hollow‐bearing trees is deficient. Recent studies have provided equivocal evidence about the effectiveness of nest box projects and have highlighted significant management costs associated with some projects. We document the functionality of 303 nest boxes installed across five different community‐led projects in southern Australia for periods of 10–25 years. As expected, we found that nest boxes lost functionality over time. However, 60% remained functional to support the Brush‐tailed Phascogale (Phascogale tapoatafa) and the Sugar Glider (Petaurus breviceps) after almost 20 years. Years installed, method of nest box attachment and tree species influenced whether boxes remained functional. Nest box construction material changed over time so could not be assessed specifically. When inspected in a single year, the Brush‐tailed Phascogale occupied 9% of functional boxes and another 48% contained their nests. The Sugar Glider occupied 15% of functional boxes and another 22% contained their nests. These values suggest the nest box installations were highly effective for these species, although more detailed study is needed to understand what contribution these installations have made to support the local populations. Maintenance of most nest boxes occurred twice a year in the first five years after installation, but many received no maintenance for periods of three years, and some 10–15 years, before our census. Our findings suggest that infrequent maintenance by community groups can sustain nest box projects over periods of several decades. Research into employing nest boxes as a management tool in Australia is still in its infancy. Further studies are needed to resolve factors that limit their effectiveness.