Structure,chaperone activity,and aggregation of wild-type and R12C mutant αB-crystallins in the presence of thermal stress and calcium ion – Implications for role of calcium in cataract pathogenesis

The current study was performed with the aim to evaluate the chaperoning ability, structural features, and aggregation propensity of wild-type and R12C mutant αB-crystallins (αB-Cry) under thermal stress and in the presence of calcium ion. The results of different spectroscopic analyses suggest that wild-type and mutant αB-Cry have dissimilar secondary and tertiary structures. Moreover, αB-Cry indicates slightly improved chaperone activity upon the R12C mutation. Thermal stress and calcium, respectively, enhance and reduce the extent of solvent-exposed hydrophobic surfaces accompanying formation of ordered and non-ordered aggregate entities in both proteins. Compared to the wild-type protein, the R12C mutant counterpart shows significant resistance against thermal and calcium-induced aggregation. In addition, in the presence of calcium, significant structural variation was accompanied by reduction in the solvent-exposed hydrophobic patches and attenuation of chaperone activity in both proteins. Additionally, gel mobility shift assay indicates the intrinsic propensity of R12C mutant αB-Cry for disulfide bridge-mediated protein dimerization. Overall, the results of this study are of high significance for understanding the molecular details of different factors that are involved in the pathomechanism of cataract disorders.     

Progress on lipid extraction from wet algal biomass for biodiesel production

Lipid recovery and purification from microalgal cells continues to be a significant bottleneck in biodiesel production due to high costs involved and a high energy demand. Therefore, there is a considerable necessity to develop an extraction method which meets the essential requirements of being safe, cost‐effective, robust, efficient, selective, environmentally friendly, feasible for large‐scale production and free of product contamination. The use of wet concentrated algal biomass as a feedstock for oil extraction is especially desirable as it would avoid the requirement for further concentration and/or drying. This would save considerable costs and circumvent at least two lengthy processes during algae‐based oil production. This article provides an overview on recent progress that has been made on the extraction of lipids from wet algal biomass. The biggest contributing factors appear to be the composition of algal cell walls, pre‐treatments of biomass and the use of solvents (e.g. a solvent mixture or solvent‐free lipid extraction). We compare recently developed wet extraction processes for oleaginous microalgae and make recommendations towards future research to improve lipid extraction from wet algal biomass.     

Collophora hispanica,a New Pathogen and Potential Threat to the Almond Industry in Iran

Trunk diseases are potential threats for almond productivity and longevity worldwide, including Iran. In a recent survey on fungal species associated with trunk diseases of almonds in north‐western Iran, Collophora isolates (tentatively identified as Collophora hispanica) were recovered with high frequency from wood samples with internal necrosis and brown to black vascular streaking of almond trees showing symptoms of decline. However, the pathogenic potential of Collophora isolates on almond trees in Iran remains unproven. In this study, the identity of the isolates was further confirmed as C. hispanica based on a combination of morphological data and sequence data of ITS‐rDNA region, and pathogenicity of C. hispanica isolates on almond was evaluated using excised shoot method and in greenhouse experiments. Collophora hispanica isolates induced lesions statistically different from the control, in both excised shoot method and greenhouse assays. Significant differences were observed among the isolates in the length of the lesion induced on wood. Collophora hispanica should be considered as the main trunk pathogens of almond trees in north‐western region of Iran. The distribution and host range of this new pathogen on almond remains to be studied.     

Improvement in infected wound healing in type 1 diabetic rat by the synergistic effect of photobiomodulation therapy and conditioned medium

We investigated the effects of photobiomodulation therapy (PBMT) and conditioned medium (CM) of human bone marrow mesenchymal stem cells (hBM-MSC) individually and/or in combination on the stereological parameters and the expression of basic fibroblast growth factor (bFGF), hypoxia-inducible factor (HIF-1α), and stromal cell–derived factor-1α (SDF-1α) in a wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) in diabetic rats. CM was provided by culturing hBM-MSCs. Type 1 diabetes mellitus (T1DM) was induced in 72 rats, divided into four groups, harboring 18 rats each: group 1 served as a control group, group 2 received PBMT, group 3 received CM, and group 4 received CM + PBMT. On days 4, 7, and 15, six animals from each group were euthanized and the skin samples were separated for stereology examination and gene expression analysis by real-time polymerase chain reaction. In the CM + PBMT, CM, and PBMT groups, significant decreases were induced in the number of neutrophils (1460 ± 93, 1854 ± 138, 1719 ± 248) and macrophages (539 ± 69, 804 ± 63, 912 ± 41), and significant increases in the number of fibroblasts (1073 ± 116, 836 ± 75, 912 ± 41) and angiogenesis (15 230 ± 516, 13 318 ± 1116, 14 041 ± 867), compared with those of the control group (2690 ± 371, 1139 ± 145, 566 ± 90, 12 585 ± 1219). Interestingly, the findings of the stereological examination in the CM + PBMT group were statistically more significant than those in the other groups. In the PBMT group, in most cases, the expression of bFGF, HIF-1α, and SDF-1α, on day 4 (27.7 ± 0.14, 28.8 ± 0.52, 27.5 ± 0.54) and day 7 (26.8 ± 1.4, 29.6 ± 1.4, 28.3 ± 1.2) were more significant than those in the control (day 4, 19.3 ± 0.42, 25.5 ± 0.08, 22.6 ± 0.04; day 7, 22.3 ± 0.22, 28.3 ± 0.59, 24.3 ± 0.19) and other treatment groups. The application of PBMT + CM induced anti-inflammatory and angiogenic activities, and hastened wound healing process in a T1 DM model of MRSA infected wound.     

Structure–activity relationship studies of 3-dodecanoylindole-2-carboxylic acid inhibitors of cytosolic phospholipase A2α-mediated arachidonic acid release in intact platelets: variation of the keto moiety

Recently we found that 1-methyldodecanoylindole-2-carboxylic acid (1) and 1-[2-(4-carboxyphenoxy)ethyl]-3-dodecanoylindole-2-carboxylic acid (4) were inhibitors of the cytosolic phospholipase A₂α (cPLA₂α)-mediated arachidonic acid release in calcium ionophore A23187-stimulated human platelets with IC₅₀-values of 4.8 μM (1) and 0.86 μM (4). We have now replaced the 3-acyl residue of these compounds by alkylated sulfinyl-, sulfony-, sulfinamoyl-, sulfamoyl-, carbonylamino-, or carbonylaminomethyl-substituents. Structure–activity relationship studies revealed that the pronounced cellular activity of 4 strongly depends on the presence of the 3-acyl moiety. Surprisingly, when testing 4 and its derivatives in an assay with the isolated cPLA₂, none of these compounds showed an inhibitory potency at 10 μM indicating that they do not inhibit cPLA₂α in the cells by a direct interaction with the active site of the enzyme.     

Pierce into the Native Structure of Ata,a Trimeric Autotransporter of Acinetobacter baumannii ATCC 17978

International Journal of Peptide Research and Therapeutics - Acinetobacter baumannii is an important pathogen responsible for nosocomial infections worldwide. Trimeric autotransporters, the...     

Migration of periodontal ligament fibroblasts on nanometric topographical patterns: influence of filopodia and focal adhesions on contact guidance

Considered to be the "holy grail" of dentistry, regeneration of the periodontal ligament in humans remains a major clinical problem. Removal of bacterial biofilms is commonly achieved using EDTA gels or lasers. One side effect of these treatment regimens is the etching of nanotopographies on the surface of the tooth. However, the response of periodontal ligament fibroblasts to such features has received very little attention. Using laser interference lithography, we fabricated precisely defined topographies with continuous or discontinuous nanogrooves to assess the adhesion, spreading and migration of PDL fibroblasts. PDL fibroblasts adhered to and spread on all tested surfaces, with initial spreading and focal adhesion formation slower on discontinuous nanogrooves. Cells had a significantly smaller planar area on both continuous and discontinuous nanogrooves in comparison with cells on non-patterned controls. At 24 h post seeding, cells on both types of nanogrooves were highly elongated parallel to the groove long axis. Time-lapse video microscopy revealed that PDL fibroblast movement was guided on both types of grooves, but migration velocity was not significantly different from cells cultured on non-patterned controls. Analysis of filopodia formation using time-lapse video microscopy and labeling of vinculin and F-actin revealed that on nanogrooves, filopodia were highly aligned at both ends of the cell, but with increasing time filopodia and membrane protrusions developed at the side of the cell perpendicular to the cell long axis. We conclude that periodontal ligament fibroblasts are sensitive to nanotopographical depths of 85-100 μm, which could be utilized in regeneration of the periodontal ligament.     

3D QSAR studies,pharmacophore modeling,and virtual screening of diarylpyrazole–benzenesulfonamide derivatives as a template to obtain new inhibitors,using human carbonic anhydrase II as a model protein

A 3D-QSAR modeling was performed on a series of diarylpyrazole-benzenesulfonamide derivatives acting as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The compounds were collected from two datasets with the same scaffold, and utilized as a template for a new pharmacophore model to screen the ZINC database of commercially available derivatives. The datasets were divided into training, test, and validation sets. As the first step, comparative molecular field analysis (CoMFA), CoMFA region focusing and comparative molecular similarity indices analysis (CoMSIA) in parallel with docking studies were applied to a set of 41 human (h) CA II inhibitors. The validity and the prediction capacity of the resulting models were evaluated by leave-one-out (LOO) cross-validation approach. The reliability of the model for the prediction of possibly new CA inhibitors was also tested.     

Analysis of beta-hemolysis in human blood agars by Streptococcus pyogenes

The aim of the study was to assess the reliability of human blood agar media (HuBA) in identifying Streptococcus pyogenes by hemolysis analysis. We analyze several factors that might affect the accuracy of HuBA media for microbial analysis, including incubation time, blood group, Rh factor and presence of antistreptolysin-o.     

Lectins influence chondrogenesis and osteogenesis in limb bud mesenchymal cells

The role of cell surface glycoproteins in cell behavior can be characterized by their interactions with plant lectins. This study was designed to identify the effects of lectins on chondrogenesis and osteogenesis in limb bud mesenchymal cells in vitro. Limb bud mesenchymal cells from mouse embryos were cultured in high-density micromass culture. Wheat germ agglutinin (WGA), concanavalin A (ConA), peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA) and Ricinus communis agglutinin (RCA) were added separately to the culture media. Cells were cultured for 5 or 9 days, and cell viability was assayed by neutral red on day 5. The micromasses were stained with alcian blue, alizarin red S and Von Kossa stains, and alkaline phosphatase assays were also done. Dolichos biflorus agglutinin induced an increase in chondrogenesis, calcium precipitation and proteoglycan production. ConA and PNA did not affect chondrocyte differentiation but induced chondrocytes to produce more proteoglycan. Wheat germ agglutinin reduced chondrification and ossification but induced mesenchymal cells to store lipid droplets. Ricinus communis agglutinin 1 was toxic and significantly reduced cell survival. In conclusion, DBA was the most effective inducer of ossification and chondrification. Wheat germ agglutinin induced adipogenesis instead. These assays showed that lectins play important roles in limb bud development.