Effect of the concentration of protein and nanoparticles on the structure of biohybrid nanocomposites

We present colloidal nanocomposites formed by incorporating magnetite Fe₃O₄ nanoparticles (MNPs) with lysozyme amyloid fibrils (LAFs). Preparation of two types of solutions, with and without addition of salt, was carried out to elucidate the structure of MNPs-incorporated fibrillary nanocomposites and to study the effect of the presence of salt on the stability of the nanocomposites. The structural morphology of the LAFs and their interaction with MNPs were analyzed by atomic force microscopy and small-angle x-ray scattering measurements. The results indicate that conformational properties of the fibrils are dependent on the concentration of protein, and the precise ratio of the concentration of the protein and MNPs is crucially important for the stability of the fibrillary nanocomposites. Our results confirm that despite the change in fibrillary morphology induced by the varying concentration of the protein, the adsorption of MNPs on the surface of LAF is morphologically independent. Moreover, most importantly, the samples containing salt have excellent stability for up to 1 year of shelf-life.     

Therapeutic angiogenesis for revascularization in peripheral artery disease

Therapeutic angiogenesis for peripheral artery disease (PAD), achieved by gene and cell therapy, has recently raised a great deal of hope for patients who cannot undergo standard revascularizing treatment. Although pre-clinical studies gave very promising data, still clinical trials of gene therapy have not provided satisfactory results. On the other hand, cell therapy approach, despite several limitations, demonstrated more beneficial effects but initial clinical studies must be constantly validated by larger randomized, multi-center, double-blinded, placebo-controlled trials. This review focuses on previous and recent gene and cell therapy studies for limb ischemia, including both experimental and clinical research, and summarizes some important papers published in this field. Moreover, it provides a short comment on combined gene and cell therapy approach on the example of heme oxygenase-1 overexpressing cells with therapeutic properties.     

Monte Carlo Simulation of Hydration of the Guanine-Uracil Pairs with Guanine in Two Tautomeric Forms: Contribution of Water Bridging to Relative Stability of Mispairs

Abstract

Results are presented from Monte Carlo simulation of hydration of guanine-uracil mispairs by 25 and 50 water molecules. The hydration shells of three mispairs formed between “normal” dioxo form of uracil (U) and three forms of guanine (“normal” amino-oxo tautomer G and two rotamers of the “rare” amino-hydroxy tautomer G*) depend on the tautomeric forms of the guanine molecule. The simulation shows the important role of hydration effects on the relative stability of the mispairs.     

Metabolic impact assessment for heterologous protein production in Streptomyces lividans based on genome-scale metabolic network modeling

The metabolic impact exerted on a microorganism due to heterologous protein production is still poorly understood in Streptomyces lividans. In this present paper, based on exometabolomic data, a proposed genome-scale metabolic network model is used to assess this metabolic impact in S. lividans. Constraint-based modeling results obtained in this work revealed that the metabolic impact due to heterologous protein production is widely distributed in the genome of S. lividans, causing both slow substrate assimilation and a shift in active pathways. Exchange fluxes that are critical for model performance have been identified for metabolites of mouse tumor necrosis factor, histidine, valine and lysine, as well as biomass. Our results unravel the interaction of heterologous protein production with intracellular metabolism of S. lividans, thus, a possible basis for further studies in relieving the metabolic burden via metabolic or bioprocess engineering.     

Delayed post-conditioning reduces post-ischemic glutamate level and improves protein synthesis in brain

In the clinic delayed post-conditioning would represent an attractive strategy for the survival of vulnerable neurons after an ischemic event. In this paper we studied the impact of ischemia and delayed post-conditioning on blood and brain tissue concentrations of glutamate and protein synthesis. We designed two groups of animals for analysis of brain tissues and blood after global ischemia and post-conditioning, and one for analysis of blood glutamate after transient focal ischemia.     

Development of a pattern in biochemical parameters in the core and penumbra during infarct evolution after transient MCAO in rats

The period from stroke initiation to the cessation of penumbra damage spread represents a therapeutic window when expansion can be alleviated. In the present work, we studied some biochemical parameters helpful for the estimation of infarct progression and thus for the application of interventions.     

Development of a triclosan scaffold which allows for adaptations on both the A- and B-ring for transport peptides

The enoyl acyl-carrier protein reductase (ENR) enzyme is harbored within the apicoplast of apicomplexan parasites providing a significant challenge for drug delivery, which may be overcome through the addition of transductive peptides, which facilitates crossing the apicoplast membranes. The binding site of triclosan, a potent ENR inhibitor, is occluded from the solvent making the attachment of these linkers challenging. Herein, we have produced 3 new triclosan analogs with bulky A- and B-ring motifs, which protrude into the solvent allowing for the future attachment of molecular transporters for delivery.     

Dynamics of exocyclic groups in the Escherichia coli O91 O-antigen polysaccharide in solution studied by carbon-13 NMR relaxation

Carbon-13 relaxation data are reported for exocyclic groups of hexopyranosyl sugar residues in the repeating unit within the Escherichia coli O91 O-antigen polysaccharide in a dilute D₂O solution. The measurements of T ₁, T ₂ and heteronuclear nuclear Overhauser enhancements were carried out at 310 K at two magnetic fields (16.4 T, 21.1 T). The data were analyzed using the standard and extended Lipari–Szabo models, as well as a conformational jump model. The extended version of the Lipari–Szabo and the two-site jump models were most successful for the hydroxymethyl groups of Gal and GlcNAc sugar residues. Different dynamics was found for the hydroxymethyl groups associated with different configurations (d-gluco, d-galacto) of the sugar residues, the latter being faster than the former.     

Increased Cardiac Myocyte PDE5 Levels in Human and Murine Pressure Overload Hypertrophy Contribute to Adverse LV Remodeling

Background

The intracellular second messenger cGMP protects the heart under pathological conditions. We examined expression of phosphodiesterase 5 (PDE5), an enzyme that hydrolyzes cGMP, in human and mouse hearts subjected to sustained left ventricular (LV) pressure overload. We also determined the role of cardiac myocyte-specific PDE5 expression in adverse LV remodeling in mice after transverse aortic constriction (TAC).

Methodology/Principal Findings

In patients with severe aortic stenosis (AS) undergoing valve replacement, we detected greater myocardial PDE5 expression than in control hearts. We observed robust expression in scattered cardiac myocytes of those AS patients with higher LV filling pressures and BNP serum levels. Following TAC, we detected similar, focal PDE5 expression in cardiac myocytes of C57BL/6NTac mice exhibiting the most pronounced LV remodeling. To examine the effect of cell-specific PDE5 expression, we subjected transgenic mice with cardiac myocyte-specific PDE5 overexpression (PDE5-TG) to TAC. LV hypertrophy and fibrosis were similar as in WT, but PDE5-TG had increased cardiac dimensions, and decreased dP/dt_max and dP/dt_min with prolonged tau (P<0.05 for all). Greater cardiac dysfunction in PDE5-TG was associated with reduced myocardial cGMP and SERCA2 levels, and higher passive force in cardiac myocytes in vitro.

Conclusions/Significance

Myocardial PDE5 expression is increased in the hearts of humans and mice with chronic pressure overload. Increased cardiac myocyte-specific PDE5 expression is a molecular hallmark in hypertrophic hearts with contractile failure, and represents an important therapeutic target.     

A Combination of CD28 (rs1980422) and IRF5 (rs10488631) Polymorphisms Is Associated with Seropositivity in Rheumatoid Arthritis: A Case Control Study

IntroductionThe aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA).MethodsA total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti–citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA.ResultsHLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA.ConclusionsThe association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA.