Biostructural studies on PPAR nuclear receptors

The peroxisome proliferator-activated receptors (PPARs) represent a family of nuclear receptors that function as ligand-activated transcription factors, regulating genes involved in cell differentiation and various metabolic processes, especially lipid and glucose homeostasis. The PPAR family comprises three isoforms: PPARα, PPARβ/δ and PPARγ, with different tissue distribution, ligand specificitiy and physiological role. Because of their wide range of actions on glucose homeostasis, lipid metabolism and vascular inflammation, PPARs represent promising targets for the development of new drugs for the treatment of metabolic disorders such as type 2 diabetes mellitus (T2DM), dyslipidemia and atherosclerosis. Among all the subtypes, despite the undesiderable side effects associated to the drug treatment, PPARγ is still the most widely studied for its crucial role in the complex cross-talk between metabolically active tissues essential for energy balance. Then, new combination strategies using dual or pan agonists, as well as selective modulators, are currently in development. This study is aimed to understand in deep the dynamic personality of the nuclear receptors PPAR in complex with both natural and synthetic ligands that, interacting with different regions of the LBD, confer a differentiated biological response in cellular and animal models. PPARs could be then described as a ‘functionally pluripotent’ proteins being their activity mediated by ligands that, causing the functional site to adopt an active/inactive conformations, activate different structural and biological pathways depending on the co-activator/co-repressor recruited. Through a structural approach we propose to get more insights on how the biological response is variably affected by ligands depending on their binding mode and even the mutation of a single residue responsible for a structural destabilization of the LBD could be associated to rare genetic disorder. The understanding of such a mechanism required the use of more than one biophysical technology. X-ray diffraction was used as the main approach to investigate the binding mode of the selected ligands. In addition, the binding has been also characterized using other biophysical techniques such as Isotermal Titration Calorimetry (ITC) and Surface Plasmon Resonance (SPR) to obtain thermodynamic and kinetic parameters of the binding

Development of a Methodology for Condition-Based Maintenance in a Large-Scale Application Field

This paper describes a methodology, developed by the authors, for condition monitoring and diagnostics of several critical components in the large-scale applications with machines. For industry, the main target of condition monitoring is to prevent the machine stopping suddenly and thus avoid economic losses due to lack of production. Once the target is reached at a local level, usually through an R&D project, the extension to a large-scale market gives rise to new goals, such as low computational costs for analysis, easily interpretable results by local technicians, collection of data from worldwide machine installations, and the development of historical datasets to improve methodology, etc. This paper details an approach to condition monitoring, developed together with a multinational corporation, that covers all the critical points mentioned above

A bearing fault model for Independent Cart Conveyor System and its validation

Independent Cart Conveyor System is one of the most promising technology in automation industries. It combines the benefits of servo motors with the advantages of linear motors. It consists of a close path made up of modular linear motors having a curved or a straight shape that control a fleet of carts independently. Each cart is placed along the motors and it is connected, through rolling bearings, to a rail set on the motors themselves. The bearings are subject to wear and the condition monitoring of these elements is challenging for the non-stationary working conditions of variable load and variable speed profiles. This paper provides a bearing fault vibration model that takes into account the mechanical design of the cart, its motion profile, the shape of the conveyor path, the load variation and the type of fault on the rolling bearing

Growth Dynamics of Ultrathin Films of Benzo[1,2-b:4,5-b']dithiophene Derivatives on Au(111): A Photoelectron Spectroscopy Investigation

: Ultrathin films of a stereoisomeric mixture of benzo[1,2-b:4,5-b']dithiophene derivatives were grown by thermal evaporation in vacuum on Au(111), and they were studied in situ by photoelectron spectroscopy. X-ray photons from a non-monochromatic Mg Kα conventional X-ray source and UV photons from a He I discharge lamp equipped with a linear polarizer were used. He I photoemission results were compared with density functional theory (DFT) calculations: density of states (DOS) and 3D molecular orbital density distribution. Au 4f, C 1s, O 1s, and S 2p core-level components suggest a surface rearrangement as a function of film nominal thickness, with the variation of the molecular orientation, from flat-laying at the initial deposition to tilted toward the surface normal at coverages exceeding 2 nm. Eventually, the DFT results were exploited in assigning of the valence band experimental structures. Moreover, polarization-dependent photoemission confirmed the tilted arrangement of the molecules, starting at 2 nm. A variation of the work function of 1.4 eV with respect to the clean substrate was measured, together with a valence band offset of 1.3 eV between the organic layer and gold

Bio adipic acid production from sodium muconate and muconic acid: a comparison of two systems

sodium muconate and trans,trans‐muconic acid were heterogeneously hydrogenated to adipic acid, a strategic intermediate for the industry of polyamides and high performance polymers. Hydrogen pressure, metal to substrate ratio, substrate concentration and reaction temperature were varied to study the effect of these parameters on the reaction products. Commercial Pd/AC 5 % was used as catalyst and characterized by TEM, BET and XPS analyses. The results revealed that temperature is the parameter which mainly affect the reaction. Moreover, hydrogenation of trans,trans‐muconic acid is faster than sodium muconate reduction. Full conversion and full yield toward adipic acid was obtained using trans,trans‐muconic acid as substrate after 60 min at the following operating conditions: temperature=70 °C, metal/substrate=1/200 (molPd/molsub), trans,trans‐muconic acid concentration=1.42E‐02M and hydrogen pressure=1 bar. In all reactions (2E)hexenedioic acid was detected as main intermediate

Structural basis for PPAR partial or full activation revealed by a novel ligand binding mode

The peroxisome proliferator-activated receptors (PPARs) are nuclear receptors involved in the regulation of the metabolic homeostasis and therefore represent valuable therapeutic targets for the treatment of metabolic diseases. The development of more balanced drugs interacting with PPARs, devoid of the side-effects showed by the currently marketed PPARλ 3 full agonists, is considered the major challenge for the pharmaceutical companies. Here we present a structure-based virtual screening approach that let us identify a novel PPAR pan-agonist with a very attractive activity profile and its crystal structure in the complex with PPARα and PPARλ 3, respectively. In PPARα this ligand occupies a new pocket whose filling is allowed by the ligand-induced switching of the F273 side chain from a closed to an open conformation. The comparison between this pocket and the corresponding cavity in PPARλ 3 provides a rationale for the different activation of the ligand towards PPARα and PPARλ 3, suggesting a novel basis for ligand design

Electrochemical and Structural Characterization of Lanthanum-Doped Hydroxyapatite: A Promising Material for Sensing Applications

In the quest to find powerful modifiers of screen-printed electrodes for sensing applications, a set of rare earth-doped Ca10-xREx(PO4)(6)(OH)(2) (RE = La, Nd, Sm, Eu, Dy, and Tm and x = 0.01, 0.02, 0.10, and 0.20) hydroxyapatite (HAp) samples were subjected to an in-depth electrochemical characterization using electrochemical impedance spectroscopy and cyclic and square wave voltammetry. Among all of these, the inorganic phosphates doped with lanthanum proved to be the most reliable, revealing robust analytical performances in terms of sensitivity, repeatability, reproducibility, and reusability, hence paving the way for their exploitation in sensing applications. Structural data on La-doped HAp samples were also provided by using different techniques, including optical microscopy, X-ray diffraction, Rietveld refinement from X-ray data, Fourier transform infrared, and Raman vibrational spectroscopies, to complement the electrochemical characterization

Reconstructing the recent West Nile virus lineage 2 epidemic in Europe and Italy using discrete and continuous phylogeography

West Nile virus lineage 2 (WNV-2) was mainly confined to sub-Saharan Africa until the early 2000s, when it was identified for the first time in Central Europe causing outbreaks of human and animal infection. The aim of this study was to reconstruct the origin and dispersion of WNV-2 in Central Europe and Italy on a phylodynamic and phylogeographical basis. To this aim, discrete and continuous space phylogeographical models were applied to a total of 33 newly characterised full-length viral genomes obtained from mosquitoes, birds and humans in Northern Italy in the years 2013-2015 aligned with 64 complete sequences isolated mainly in Europe. The European isolates segregated into two highly significant clades: a small one including three sequences and a large clade including the majority of isolates obtained in Central Europe since 2004. Discrete phylogeographical analysis showed that the most probable location of the root of the largest European clade was in Hungary a mean 12.78 years ago. The European clade bifurcated into two highly supported subclades: one including most of the Central/East European isolates and the other encompassing all of the isolates obtained in Greece. The continuous space phylogeographical analysis of the Italian clade showed that WNV-2 entered Italy in about 2008, probably by crossing the Adriatic sea and reaching a central area of the Po Valley. The epidemic then spread simultaneously eastward, to reach the region of the Po delta in 2013, and westward to the border area between Lombardy and Piedmont in 2014; later, the western strain changed direction southward, and reached the central area of the Po valley once again in 2015. Over a period of about seven years, the virus spread all over an area of northern Italy by following the Po river and its main tributaries

Longitudinal tracking of triple labeled umbilical cord derived mesenchymal stromal cells in a mouse model of Amyotrophic Lateral Sclerosis

The translational potential of cell therapy to humans requires a deep knowledge of the interaction between transplanted cells and host tissues. In this study, we evaluate the behavior of umbilical cord mesenchymal stromal cells (UC-MSCs), labeled with fluorescent nanoparticles, transplanted in healthy or early symptomatic transgenic SOD1G93A mice (a murine model of Amyotrophic Lateral Sclerosis). The double labeling of cells with nanoparticles and Hoechst-33258 enabled their tracking for a long time in both cells and tissues. Whole-body distribution of UC-MSCs was performed by in-vivo and ex-vivo analyses 1, 7, 21 days after single intravenous or intracerebroventricular administration. By intravenous administration cells were sequestered by the lungs and rapidly cleared by the liver. No difference in biodistribution was found among the two groups. On the other hand, UC-MSCs transplanted in lateral ventricles remained on the choroid plexus for the whole duration of the study even if decreasing in number. Few cells were found in the spinal cord of SOD1G93A mice exclusively. No migration in brain parenchyma was observed. These results suggest that the direct implantation in brain ventricles allows a prolonged permanence of cells close to the damaged areas and makes this method of tracking reliable for future studies of efficacy