Capsaicin but not Genistein Influences Modulation of Lipid Parameters by Obestatin in DIO-C57BL/6 Mice

International Journal of Peptide Research and Therapeutics - Capsaicin from chillies and genistein from soya bean have been shown to reduce cholesterol and triglyceride levels effectively. This...     

Loop-mediated isothermal amplification based identification of entomopathogenic nematodes Heterorhabditis spp. and Steinernema spp. from soil DNA

Entomopathogenic nematodes (EPNs) of the genera Heterorhabditis and Steinernema kill insects with the help of their symbiotic bacteria. They are widely used as biocontrol agents to manage insect pests of crops. The infective juveniles (IJ) of EPNs are isolated from soil by insect baiting technique, which is labour-intensive, time-consuming, wasteful, and inefficient. Here, we present loop-mediated isothermal amplification (LAMP) assays for rapid detection of Heterorhabditis spp. (Het-LAMP) and Steinernema spp. (Ste-LAMP) from total soil DNA. The primers for Het-LAMP and Ste-LAMP were designed using ITS and 18S rDNA regions of genomic DNA. The LAMP reactions could be completed in 60 min, at 66 °C and 68 °C, respectively, followed by termination at 85 °C for 5 min. The assays were highly sensitive and could detect up to 0.02 picograms of Heterorhabditis DNA and 96 picograms of Steinernema DNA in a 25 μl reaction. Both the assays were specific for the target nematode species and detected the presence of a single IJ in the total DNA extracted from 250 mg of soil. The assays developed in this study would be of immense utility for the efficient detection and identification of native EPNs in large-scale surveys. These assays are amenable to automation and could be used to develop convenient detection kits for point-of-service diagnosis of EPNs in the field without the need for a trained and experienced personnel.

     

Design,Synthesis and Molecular Docking Studies of Novel Indole–Isoxazole–Triazole Conjugates as Potent Antibacterial Agents

Russian Journal of Bioorganic Chemistry - In search of better antibacterial agents, a series of novel 5-((aryl)methyl)-3-(1H-indol-2-yl)isoxazole (IIIa–e) and...     

Microarray analysis of miRNA expression profiles following whole body irradiation in a mouse model

Abstract

Context: Accidental exposure to life-threatening radiation in a nuclear event is a major concern; there is an enormous need for identifying biomarkers for radiation biodosimetry to triage populations and treat critically exposed individuals.

Objective: To identify dose-differentiating miRNA signatures from whole blood samples of whole body irradiated mice.

Methods: Mice were whole body irradiated with X-rays (2?Gy–15?Gy); blood was collected at various time-points post-exposure; total RNA was isolated; miRNA microarrays were performed; miRNAs differentially expressed in irradiated vs. unirradiated controls were identified; feature extraction and classification models were applied to predict dose-differentiating miRNA signature.

Results: We observed a time and dose responsive alteration in the expression levels of miRNAs. Maximum number of miRNAs were altered at 24-h and 48-h time-points post-irradiation. A 23-miRNA signature was identified using feature selection algorithms and classifier models. An inverse correlation in the expression level changes of miR-17 members, and their targets were observed in whole body irradiated mice and non-human primates.

Conclusion: Whole blood-based miRNA expression signatures might be used for predicting radiation exposures in a mass casualty nuclear incident.     

Partial Purification and Characterization of a Bacteriocin DT24 Produced by Probiotic Vaginal Lactobacillus brevis DT24 and Determination of its Anti-Uropathogenic Escherichia coli Potential

The emergence of antibiotic resistance has increased the interest for finding new antimicrobials in the past decade. Probiotic Lactic acid bacteria producing antimicrobial proteins like bacteriocin can be excellent agents for development as novel therapeutic agents and complement to conventional antibiotic therapy. Uropathogenic Escherichia coli, most causative agent of Urinary tract infection, has developed resistance to various antibiotics. In the present investigation, antibacterial substance like bacteriocin (Bacteriocin DT24) produced by probiotic Lactobacillus brevis DT24 from vaginal sample of healthy Indian woman was partially purified and characterized. It was efficiently working against various pathogens, that is, Uropathogenic E. coli, Enterococcus faecium, Enterococcus faecalis and Staphylococcus aureus. The antimicrobial peptide was relatively heat resistant and also active over a broad range of pH 2–10. It has been partially purified by ammonium sulfate precipitation and gel filtration chromatography and checked on reverse-phase high-performance liquid chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of bacteriocin DT24 was approximately 7-kDa protein. The peptide is inactivated by proteolytic enzymes, trypsin and lipase but not when treated with catalase, α-amylase and pepsin. It showed bacteriostatic mode of action against uropathogenic E. coli. Such characteristics indicate that this bacteriocin-producing probiotic may be a potential candidate for alternative agents to control urinary tract infections and other pathogens.     

Refining the Plasmid-Encoded Type IV Secretion System Substrate Repertoire of Coxiella burnetii

The intracellular bacterial agent of Q fever, Coxiella burnetii, translocates effector proteins into its host cell cytosol via a Dot/Icm type IV secretion system (T4SS). The T4SS is essential for parasitophorous vacuole formation, intracellular replication, and inhibition of host cell death, but the effectors mediating these events remain largely undefined. Six Dot/Icm substrate-encoding genes were recently discovered on the C. burnetii cryptic QpH1 plasmid, three of which are conserved among all C. burnetii isolates, suggesting that they are critical for conserved pathogen functions. However, the remaining hypothetical proteins encoded by plasmid genes have not been assessed for their potential as T4SS substrates. In the current study, we further defined the T4SS effector repertoire encoded by the C. burnetii QpH1, QpRS, and QpDG plasmids that were originally isolated from acute-disease, chronic-disease, and severely attenuated isolates, respectively. Hypothetical proteins, including those specific to QpRS or QpDG, were screened for translocation using the well-established Legionella pneumophila T4SS secretion model. In total, six novel plasmid-encoded proteins were translocated into macrophage-like cells by the Dot/Icm T4SS. Four newly identified effectors are encoded by genes present only on the QpDG plasmid from severely attenuated Dugway isolates, suggesting that the presence of specific effectors correlates with decreased virulence. These results further support the idea of a critical role for extrachromosomal elements in C. burnetii pathogenesis.     

Cytidine derivatives as IspF inhibitors of Burkolderia pseudomallei

Published biological data suggest that the methyl erythritol phosphate (MEP) pathway, a non-mevalonate isoprenoid biosynthetic pathway, is essential for certain bacteria and other infectious disease organisms. One highly conserved enzyme in the MEP pathway is 2C-methyl-d-erythritol 2,4-cyclodiphosphate synthase (IspF). Fragment-bound complexes of IspF from Burkholderia pseudomallei were used to design and synthesize a series of molecules linking the cytidine moiety to different zinc pocket fragment binders. Testing by surface plasmon resonance (SPR) found one molecule in the series to possess binding affinity equal to that of cytidine diphosphate, despite lacking any metal-coordinating phosphate groups. Close inspection of the SPR data suggest different binding stoichiometries between IspF and test compounds. Crystallographic analysis shows important variations between the binding mode of one synthesized compound and the pose of the bound fragment from which it was designed. The binding modes of these molecules add to our structural knowledge base for IspF and suggest future refinements in this compound series.     

Discovery of novel inhibitors targeting the Mycobacterium tuberculosis O-acetylserine sulfhydrylase (CysK1) using virtual high-throughput screening

Cysteine biosynthesis in Mycobacterium tuberculosis (MTB) is crucial for this pathogen to combat oxidative stress and for long term survival in the host. Hence inhibition of this pathway is attractive for developing novel drugs against tuberculosis. In the present study, the crystal structure of the mycobacterial enzyme O-acetylserine sulfhydrylase CysK1 bound to an oligopeptide inhibitor was used as a framework for virtual screening of the BITS-Pilani in-house database to identify new scaffolds as CysK1 inhibitors. Thirty compounds were synthesized and evaluated in vitro for their ability to inhibit CysK1, activity against M. tuberculosis and cytotoxicity as steps towards the derivation of structure–activity relationships (SAR) and lead optimization. Compound 8-nitro-4-(2-(trifluoromethyl)phenyl)-4,4a-dihydro-2H-pyrimido[5,4-e]thiazolo[3,2-a]pyrimidine-2,5(3H)-dione (4n) emerged as the most promising lead with an IC₅₀ of 17.7 μM for purified CysK1 and MIC of 7.6 μM for M. tuberculosis, with little or no cytotoxicity (>50 μM).