Bacteriophages and its applications: an overview

Bacteriophages (or phages), the most abundant viral entity of the planet, are omni-present in all the ecosystems. On the basis of their unique characteristics and anti-bacterial property, phages are being freshly evaluated taxonomically. Phages replicate inside the host either by lytic or lysogenic mode after infecting and using the cellular machinery of a bacterium. Since their discovery by Twort and d’Herelle in the early 1900s, phage became an important agent for combating pathogenic bacteria in clinical treatments and its related research gained momentum. However, due to recent emergence of bacterial resistance on antibiotics, applications of phage (phage therapy) become an inevitable option of research. Phage particles become popular as a biotechnological tool and treatment of pathogenic bacteria in a range of applied areas. However, there are few concerns over the application of phage-based solutions. This review deals with the updated phage taxonomy (ICTV 2015 Release and subsequent revision) and phage biology and the recent development of its application in the areas of biotechnology, biosensor, therapeutic medicine, food preservation, aquaculture diseases, pollution remediation, and wastewater treatment and issues related with limitations of phage-based remedy.     

Regulatory role of endoplasmic reticulum resident chaperone protein ERp29 in anti-murine β-coronavirus host cell response

Gap junctional intercellular communication (GJIC) involving astrocytes is important for proper CNS homeostasis. As determined in our previous studies, trafficking of the predominant astrocyte GJ protein, Connexin43 (Cx43), is disrupted in response to infection with a neurotropic murine β-coronavirus (MHV-A59). However, how host factors are involved in Cx43 trafficking and the infection response is not clear. Here, we show that Cx43 retention due to MHV-A59 infection was associated with increased ER stress and reduced expression of chaperone protein ERp29. Treatment of MHV-A59–infected astrocytes with the chemical chaperone 4-sodium phenylbutyrate increased ERp29 expression, rescued Cx43 transport to the cell surface, increased GJIC, and reduced ER stress. We obtained similar results using an astrocytoma cell line (delayed brain tumor) upon MHV-A59 infection. Critically, delayed brain tumor cells transfected to express exogenous ERp29 were less susceptible to MHV-A59 infection and showed increased Cx43-mediated GJIC. Treatment with Cx43 mimetic peptides inhibited GJIC and increased viral susceptibility, demonstrating a role for intercellular communication in reducing MHV-A59 infectivity. Taken together, these results support a therapeutically targetable ERp29-dependent mechanism where β-coronavirus infectivity is modulated by reducing ER stress and rescuing Cx43 trafficking and function.     

Computational screening,ensemble docking and pharmacophore analysis of potential gefitinib analogues against epidermal growth factor receptor

The observable mutated isoforms of epidermal growth factor receptor (EGFR) are important considerable therapeutic benchmarks in moderating the non-small cell lung cancer (NSCLC). Recently, quinazoline-based ATP competitive inhibitors have been developed against the EGFR; however, these imply the mutation probabilities, which contribute to the discovery of high probable novel inhibitors for EGFR mutants. Therefore, SAR-based bioactivity analysis, molecular docking and computational toxicogenomics approaches were performed to identify and evaluate new analogs of gefitinib against the ligand-binding domain of the EGFR double-mutated model. From the diverse groups of molecular clustering and molecular screening strategies, top high-binding gefitinib-analogues were identified and studied against EGFR core cavity through three-phase ensemble docking approach. Resulted high possible leads showed good binding orientations than gefitinib (positive control) thus they were subjected to pharmacophore analysis that possesses possible molecular assets to tight binding with EGFR domain. Residues Ser720, Arg841 and Trp880 were observed as novel hot spots and involved in H-bonds, pi-stacking and π-cation interactions that contribute additional electrostatic potency to sustain stability and complexity of protein-ligand complexes, thus they have ability to profoundly adopted by pharmacophoric features. Furthermore, lead molecules have an inhibition percent probability, anticancer potency, toxic impacts, flexible pharmacokinetics, potential gene-chemical interactions towards EGFR were revealed by computational systems biology tools. Our multiple screening strategies confirmed that the druggable sub-pocket was crucial to strong EGFR-ligand binding. The essential pharmacophoric features of ligands provided viewpoints for new inhibitors envisaging, and predicted scaffolds could used as anticancer agents against selected EGFR mutated isoforms.     

In silico screening and identification of potential GSK3β inhibitors

Abstract

Glycogen synthase kinase-3β (GSK3β) has been reported for its impact on multitude biological processes from cell proliferation to apoptosis. The increase in the ratio of active/inactive GSK3β is the major factor associated in the etiology of several psychiatric diseases, diabetes, muscle hypertrophy, neurodegenerative diseases, and some cancers. These findings made GSK3β a promising therapeutic target, and the interest in the discovery, synthesis of novel drugs to effectively attenuate its function with probably no side effects has been increasing in the chronology of GSK3β drug discovery. In the present study, we applied a combination of computational tools on a chemical library for the virtual discovery of their potency to inhibit GSK3β. The chemical library was screened against a set of filters at different levels. Finally, five compounds in the chemical library were found to potentially inhibit GSK3β with no toxic effects. Furthermore, binding mode analysis revealed that all the compounds bound to the ATP site and most of the hydrogen bonding interactions are conserved as in GSK3β structures deposited in PDB.     

Milk fermented with probiotic strains Lactobacillus rhamnosus MTCC: 5957 and Lactobacillus rhamnosus MTCC: 5897 ameliorates the diet-induced hypercholesterolemia in rats

The current study was intended to investigate the cholesterol-lowering potential of the two Lactobacillus rhamnosus probiotic strains, LR 5957 and LR 5897, isolated from ‘dahi’. Cholesterol-lowering ability of both strains was determined in in vitro conditions. For in vivo investigations, the Wistar rats were randomly assigned into five groups and treated with different diets: standard diet (SD), high-cholesterol diet (HCD), HCD with Milk, HCD with LR 5957–fermented milk, and HCD with LR 5897–fermented milk. After 3 months of feeding, different parameters of hypercholesterolemia were measured in blood, feces, liver, and kidney. Both the strains, LR 5957 and LR 5897, showed the ability to grow in the presence of cholesterol and eliminate the cholesterol under in vitro conditions. In vivo results indicate that consumption of probiotic-fermented milk has significantly reduced the HCD-induced body weight, hyperlipidemia, and hepatic lipids (total cholesterol and triacylglycerol). Further, increased cholesterol excretion in feces was also observed in probiotic-fed groups. The studied fermented milk also helped to maintain healthy liver and kidney by increasing the antioxidant activities and decreasing the lipid peroxidation. Consumption of probiotic-fermented milk also found to decrease the mRNA expression of the inflammatory markers TNF-α and IL-6 in the liver. Overall, our results indicate that the L. rhamnosus strains, LR 5957 and LR 5897, are two potential probiotic strains that can ameliorate the diet-induced hypercholesterolemia.