Immunomodulatory agents for COVID-19 treatment: possible mechanism of action and immunopathology features

Molecular and Cellular Biochemistry - The novel coronavirus pandemic has emerged as one of the significant medical-health challenges of the current century. The World Health Organization has named...     

Proline-Functionalized Graphene Oxide Nanoparticles (GO–Pro NPs) Mitigate Salt-Induced Adverse Effects on Morpho-Physiological Traits and Essential Oils Constituents in Moldavian Balm (Dracocephalum moldavica L.)

Many methodologies have been established to lessen negative impacts of salinity on plants. Of those methodologies, nanoparticles (NPs) application has achieved great importance thanks to their unique physico-chemical properties. Consequently, formerly respecting encouraging impacts of graphene oxide (GO) and proline (Pro) on different plant processes under non-stress and stress conditions, proline-functionalized graphene oxide nanoparticles “GO–Pro NPs” were synthesized and characterized. Graphite powder, as starting material, was used to synthesize GO using modified Hummers method followed by functionalization of its surface by proline in basic media. Afterward, GO–Pro NPs, GO and Pro, each at 0, 50 and 100 mg L^?1 concentrations with three replications, were applied on Moldavian balm (Dracocephalum moldavica L.) plants to assay their effects under non-stress (0 mM) and salt stress (50 and 100 mM) conditions. GO–Pro NPs and Pro effectively alleviated negative effects of salinity through increasing morphological parameters, photosynthetic pigments, chlorophyll fluorescence parameters, chlorophyll index (SPAD), and membrane stability index (MSI) and decreasing hydrogen peroxide and malondialdehyde, as well. Also application of GO–Pro NPs enhanced proline, antioxidant enzymes activities, and most dominant constituents of essential oil. The highest MSI (48.87%) and proline content (15.36 µM g^?1 FW) were observed in plant treated with GO–Pro NPs (50 mg L^?1) under 100 mM NaCl salinity stress. The GO–Pro NPs treatment at lower dose (50 mg L^?1) could be introduced as the best preservative treatment for Moldavian balm under salt stress. GO application mostly had no effect on the measured parameters announcing it as carrier for Pro to enhance its efficiency. In conclusion, GO–Pro NPs application could promote Moldavian balm performance and essential oil under salinity presenting GO–Pro NPs as new treatment against stress conditions.

     

First volumetric records of airborne Cladosporium and Alternaria spores in the atmosphere of Al Khor (northern Qatar): a preliminary survey

Aerobiologia - Daily monitoring of airborne fungal spores was carried out for the first time in Al Khor city, Qatar, using a Hirst type 7-day recording volumetric spore trap, from May 2017 to May...     

Discovery of a novel and conserved Plasmodium falciparum exported protein that is important for adhesion of PfEMP1 at the surface of infected erythrocytes

Plasmodium falciparum virulence is linked to its ability to sequester in post‐capillary venules in the human host. Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is the main variant surface antigen implicated in this process. Complete loss of parasite adhesion is linked to a large subtelomeric deletion on chromosome 9 in a number of laboratory strains such as D10 and T9‐96. Similar to the cytoadherent reference line FCR3, D10 strain expresses PfEMP1 on the surface of parasitized erythrocytes, however without any detectable cytoadhesion. To investigate which of the deleted subtelomeric genes may be implicated in parasite adhesion, we selected 12 genes for D10 complementation studies that are predicted to code for proteins exported to the red blood cell. We identified a novel single copy gene (PF3D7_0936500) restricted to P. falciparum that restores adhesion to CD36, termed here virulence‐associated protein 1 (Pfvap1). Protein knockdown and gene knockout experiments confirmed a role of PfVAP1 in the adhesion process in FCR3 parasites. PfVAP1 is co‐exported with PfEMP1 into the host cell via vesicle‐like structures called Maurer's clefts. This study identifies a novel highly conserved parasite molecule that contributes to parasite virulence possibly by assisting PfEMP1 to establish functional adhesion at the host cell surface.     

First efficient CRISPR‐Cas9‐mediated genome editing in Leishmania parasites

Protozoan pathogens that cause leishmaniasis in humans are relatively refractory to genetic manipulation. In this work, we implemented the CRISPR‐Cas9 system in Leishmania parasites and demonstrated its efficient use for genome editing. The Cas9 endonuclease was expressed under the control of the Dihydrofolate Reductase‐Thymidylate Synthase (DHFR‐TS) promoter and the single guide RNA was produced under the control of the U6snRNA promoter and terminator. As a proof of concept, we chose to knockout a tandemly repeated gene family, the paraflagellar rod‐2 locus. We were able to obtain null mutants in a single round of transfection. In addition, we confirmed the absence of off‐target editions by whole genome sequencing of two independent clones. Our work demonstrates that CRISPR‐Cas9‐mediated gene knockout represents a major improvement in comparison with existing methods. Beyond gene knockout, this genome editing tool opens avenues for a multitude of functional studies to speed up research on leishmaniasis.     

Quantitative proteomic analysis of cabernet sauvignon grape cells exposed to thermal stresses reveals alterations in sugar and phenylpropanoid metabolism

Grapes (Vitis vinifera) are a valuable fruit crop and wine production is a major industry. Global warming and expanded range of cultivation will expose grapes to more temperature stresses in future. Our study investigated protein level responses to abiotic stresses, with particular reference to proteomic changes induced by the impact of four different temperature stress regimes, including both hot and cold temperatures, on cultured grape cells. Cabernet Sauvignon cell suspension cultures grown at 26°C were subjected to 14 h of exposure to 34 and 42°C for heat stress, and 18 and 10°C for cold stress. Cells from the five temperatures were harvested in biological triplicates and label‐free quantitative shotgun proteomic analysis was performed. A total of 2042 non‐redundant proteins were identified from the five temperature points. Fifty‐five proteins were only detected in extreme heat stress conditions (42°C) and 53 proteins were only detected at extreme cold stress conditions (10°C). Gene Ontology (GO) annotations of differentially expressed proteins provided insights into the metabolic pathways that are involved in temperature stress in grape cells. Sugar metabolism displayed switching between alternative and classical pathways during temperature stresses. Additionally, nine proteins involved in the phenylpropanoid pathway were greatly increased in abundance at extreme cold stress, and were thus found to be cold‐responsive proteins. All MS data have been deposited in the ProteomeXchange with identifier PXD000977 ( http://proteomecentral.proteomexchange.org/dataset/PXD000977 ).     

Aqueous Fraction of Beta vulgaris Ameliorates Hyperglycemia in Diabetic Mice due to Enhanced Glucose Stimulated Insulin Secretion,Mediated by Acetylcholine and GLP-1, and Elevated Glucose Uptake via Increased Membrane Bound GLUT4 Transporters

BackgroundThe study was designed to investigate the probable mechanisms of anti-hyperglycemic activity of B. Vulgaris.ConclusionFindings of the present study clearly prove the role of Acetylcholine and GLP-1 in the Insulin secreting activity of B. Vulgaris. Increased glucose uptake in the skeletal muscles and subsequent glycogen synthesis may also play a part in the anti-hyperglycemic activity of B. Vulgaris.     

Comparative Genomic and Phylogenetic Analyses of Gammaproteobacterial glg Genes Traced the Origin of the Escherichia coli Glycogen glgBXCAP Operon to the Last Common Ancestor of the Sister Orders Enterobacteriales and Pasteurellales

Production of branched α-glucan, glycogen-like polymers is widely spread in the Bacteria domain. The glycogen pathway of synthesis and degradation has been fairly well characterized in the model enterobacterial species Escherichia coli (order Enterobacteriales, class Gammaproteobacteria), in which the cognate genes (branching enzyme glgB, debranching enzyme glgX, ADP-glucose pyrophosphorylase glgC, glycogen synthase glgA, and glycogen phosphorylase glgP) are clustered in a glgBXCAP operon arrangement. However, the evolutionary origin of this particular arrangement and of its constituent genes is unknown. Here, by using 265 complete gammaproteobacterial genomes we have carried out a comparative analysis of the presence, copy number and arrangement of glg genes in all lineages of the Gammaproteobacteria. These analyses revealed large variations in glg gene presence, copy number and arrangements among different gammaproteobacterial lineages. However, the glgBXCAP arrangement was remarkably conserved in all glg-possessing species of the orders Enterobacteriales and Pasteurellales (the E/P group). Subsequent phylogenetic analyses of glg genes present in the Gammaproteobacteria and in other main bacterial groups indicated that glg genes have undergone a complex evolutionary history in which horizontal gene transfer may have played an important role. These analyses also revealed that the E/P glgBXCAP genes (a) share a common evolutionary origin, (b) were vertically transmitted within the E/P group, and (c) are closely related to glg genes of some phylogenetically distant betaproteobacterial species. The overall data allowed tracing the origin of the E. coli glgBXCAP operon to the last common ancestor of the E/P group, and also to uncover a likely glgBXCAP transfer event from the E/P group to particular lineages of the Betaproteobacteria.