Cytotoxic and apoptotic properties of a novel nano-toxin formulation based on biologically synthesized silver nanoparticle loaded with recombinant truncated pseudomonas exotoxin A

Bacterial toxins have received a great deal of attention in the development of antitumor agents. Currently, these protein toxins were used in the immunotoxins as a cancer therapy strategy. Despite the successful use of immunotoxins, immunotherapy strategies are still expensive and limited to hematologic malignancies. In the current study, for the first time, a nano-toxin comprised of truncated pseudomonas exotoxin (PE38) loaded silver nanoparticles (AgNPs) were prepared and their cytotoxicity effect was investigated on human breast cancer cells. The PE38 protein was cloned into pET28a and expressed in Escherichia coli, BL21 (DE3), and purified using metal affinity chromatography and was analyzed by 15% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. AgNPs were biologically prepared using cell-free supernatant of E. Coli K12 strain. Nanoparticle formation was characterized by energy dispersive spectroscopy, transmission electron microscopy, and dynamic light scattering. The PE38 protein was loaded on AgNPs and prepared the PE38-AgNPs nano-toxin. Additionally, in vitro release indicated a partial slow release of toxin in about 100 hr. The nano-toxin exhibited dose-dependent cytotoxicity on MCF-7 cells. Also, real-time polymerase chain reaction results demonstrated the ability of nano-toxin to upregulate Bax/Bcl-2 ratio and caspase-3, -8, -9, and P53 apoptotic genes in the MCF-7 tumor cells. Apoptosis induction was determined by Annexin-V/propidium flow cytometry and caspases activity assay after treatment of cancer cells with the nano-toxin. In general, in the current study, the nano-toxin exhibit an inhibitory effect on the viability of breast cancer cells through apoptosis, which suggests that AgNPs could be used as a delivery system for targeting of toxins to cancer cells.     

Linum mucronatum: organ to organ lignan variations

The percentage of podophyllotoxin (PTOX) and its congener lignans were measured by HPLC in Linum mucronatum ssp. mucronatum (Linaceae) fresh plant organs. The highest amounts of PTOX (0.595 +/- 0.060% g/g dry wt) and 6-methoxypodophyllotoxin (MPTOX) (1.491 +/- 0.125% g/g dry wt) were found in the plant sexual organs. Whereas, the highest levels of beta-peltatin, 5'-demethoxy-MPTOX and yatein were found in not developed buds, petals and sepals, respectively.     

Using the variability of linkage disequilibrium between subpopulations to infer sweeps and epistatic selection in a diverse panel of chickens

A whole-genome scan for identifying selection acting on pairs of linked loci is proposed and implemented. The scan is based on , one of Ohta''s 1982 measures of between-population linkage disequilibrium (LD). An approximate empirical null distribution for the statistic is suggested. Although the partitioning of LD into between-population components was originally used to investigate epistatic selection, we demonstrate that values of may also be influenced by single-locus selective sweeps with linkage but no epistasis. The proposed scan is implemented in a diverse panel of chickens including 72 distinct breeds genotyped at 538 298 single-nucleotide polymorphisms. In all, 1723 locus pairs are identified as putatively corresponding to a selective sweep or epistatic selection. These pairs of loci generally cluster to form overlapping or neighboring signals of selection. Known variants that were expected to have been under selection in the panel are identified, as well as an assortment of novel regions that have putatively been under selection in chickens. Notably, a promising pair of genes located 8 MB apart on chromosome 9 are identified based on as demonstrating strong evidence of dispersive epistatic selection between populations.     

Identification of candidate microRNA biomarkers in renal fibrosis: a meta-analysis of profiling studies

Abstract

The prognostic, diagnostic and therapeutic value of microRNA (miRNA) expression aberrations in renal fibrosis has been studied in recent years. However, the miRNA expression profiling efforts have led to inconsistent results between the studies. The aim of this study was to perform a meta-analysis on the renal fibrosis miRNA expression profiling studies to identify candidate diagnostic biomarkers. We performed comprehensive literature searches in several databases to identify miRNA expression studies of renal fibrosis in animal models and humans. The miRNAs expression data were extracted from 20 included studies, and both miRNA vote-counting strategy and Robust Rank Aggregation method were utilized to identify significant miRNA meta-signatures. The predicted and validated targets of miRNA meta-signature were obtained by using MultiMiR package in 11 databases. Then a gene set enrichment analysis (KEGG, PANTHER pathways and GO processes) were carried out with GeneCodis web tool to recognize pathways that are most strongly influenced by modified expressions of these miRNAs. We recognized in both meta-analysis approaches a significant miRNA meta-signature of five up-regulated (miR-142-3p, miR-223-3p, miR-21-5p, miR-142-5p and miR-214-3p) and two down-regulated (miR-29c-3p and miR-200a-3p) miRNAs. Enrichment analysis confirmed that miRNA meta-signature cooperatively target functionally related genes in signalling and developmental pathways in renal fibrosis. This meta-analysis identified seven highly significant and consistently dysregulated miRNAs from 20 datasets, as the focus of future investigations to discover their potential influence to renal fibrosis and their clinical utility as biomarkers and/or as therapeutic mediators against chronic kidney disease..     

Characterisation of extracellular vesicles isolated from hydatid cyst fluid and evaluation of immunomodulatory effects on human monocytes

Hydatidosis is a disease caused by the larval stage of Echinococcus granulosus, which involves several organs of intermediate hosts. Evidence suggests a communication between hydatid cyst (HC) and hosts via extracellular vesicles. However, a little is known about the communication between EVs derived from HC fluid (HCF) and host cells. In the current study, EVs were isolated using differential centrifugation from sheep HCF and characterized by western blot, electron microscope and size distribution analysis. The uptake of EVs by human monocyte cell line (THP-1) was evaluated. The effects of EVs on the expression levels of pro- and anti-inflammatory cytokines were investigated using quantitative real-time PCR (RT-PCR), 3 and 24 h after incubation. Moreover, the cytokine level of IL-10 was evaluated in supernatant of THP-1 cell line at 3 and 24 h. EVs were successfully isolated and showed spherical shape with size distribution at 130.6 nm. After 3 h, the expression levels of pro-inflammatory cytokine genes (IL1Β, IL15 and IL8) were upregulated, while after 24 h, the expression levels of pro-inflammatory cytokines were decreased and IL13 gene expression showed upregulation. A statistically significant increase was seen in the levels of IL-10 after 24 h. The main mechanism of the communication between EVs derived from HCF and their host remains unclear; however, time-dependent anti-inflammatory effects in our study suggest that HC may modulate the immune responses via EVs.     

Water-retention additives’ effects on plant water status and some physiological parameters of two olive cultivars under reduced irrigation regimes

In arid and semi-arid zones of world, the majority of annual rainfall or irrigation water is lost due to high evaporation from the soil. The amount of available water in soil can be increased by surface mulching. However, the effect varies with soils, climate and kind of mulch material used. Some physiological and biochemical parameters of two olive cultivars (‘Konservolea’ and ‘Manzanilla’) as affected by different water-retention additives (organic, chemical and mineral mulches and hydrogel) and two amounts of irrigation water were studied in pot experiments during 2013. Water stress affects plant water relations and photosynthesis and caused oxidative stress in olive. Our results confirmed that water-retention additives partly mitigated the adverse effects of water stress on olive restoring most of the measured parameters similar to those of control unstressed plants. Mulching treatment enhanced antioxidative defenses and reduced water deficit-induced oxidative damage in olive compared to zero mulching treatment. The results indicated that de-oiled olive pomace mulch and pistachio shell mulch—as new mulch materials—proved to be very effective for soil water conservation under arid conditions. It can be concluded that water management through mulch application can strongly influence the cultivar response to water deficit.     

Human Neutrophil Peptide-1 (HNP-1): A New Anti-Leishmanial Drug Candidate

The toxicity of available drugs for treatment of leishmaniasis, coupled with emerging drug resistance, make it urgent to find new therapies. Antimicrobial peptides (AMPs) have a strong broad-spectrum antimicrobial activity with distinctive modes of action and are considered as promising therapeutic agents. The defensins, members of the large family of AMPs, are immunomodulatory molecules and important components of innate immune system. Human neutrophil peptide-1 (HNP-1), which is produced by neutrophils, is one of the most potent defensins. In this study, we described anti-parasitic activity of recombinant HNP-1 (rHNP-1) against Leishmania major promastigotes and amastigotes. Furthermore, we evaluated the immunomodulatory effect of rHNP-1 on parasite-infected neutrophils and how neutrophil apoptosis was affected. Our result showed that neutrophils isolated from healthy individuals were significantly delayed in the onset of apoptosis following rHNP-1 treatment. Moreover, there was a noteworthy increase in dying cells in rHNP-1- and/or CpG–treated neutrophils in comparison with untreated cells. There is a considerable increase in TNF-α production from rHNP-1-treated neutrophils and decreased level of TGF-β concentration, a response that should potentiate the immune system against parasite invasion. In addition, by using real-time polymerase chain reaction (real-time PCR), we showed that in vitro infectivity of Leishmania into neutrophils is significantly reduced following rHNP-1 treatment compared to untreated cells.