1-N6-Etheno-ADP-ribosylation of elongation factor-2 by diphtheria toxin

AbstractDiphtheria toxin fragment A is able to inhibit protein synthesis in the eukaryotic cell by ADP-ribosylating the diphthamide residue of elongation factor-2 (EF-2) [(1980) J. Biol. Chem. 255, 10710-10720]. The reaction requires NAD as ADP-ribose donor. This work reports on the capacity of an NAD analog, the nicotinamide 1-N6-ethenoadenine dinucleotide (ϵNAD), to be a substrate of diphtheria toxin fragment A in the transferring reaction of the fluorescent moiety, the ϵADP-ribose, to the EF-2. As a consequence of the transfer of the ϵADP-ribosyl moiety to the EF-2, there is an increase in the emission intensity of the fluorophore and a blue shift in its emission maximum. The ϵADP-ribosylated EF-2, like ADP-ribosylated EF-2, retains the capacity to bind GTP and ribosome. The utility of introducing a fluorescent probe in a well defined point of the EF-2 molecule for conformational or binding studies is discussed

SIRT3 Modulates Endothelial Mitochondrial Redox State during Insulin Resistance

Emerging evidence indicates that defects in sirtuin signaling contribute to impaired glucose and lipid metabolism, resulting in insulin resistance (IR) and endothelial dysfunction. Here, we examined the effects of palmitic acid (PA) treatment on mitochondrial sirtuins (SIRT2, SIRT3, SIRT4, and SIRT5) and oxidative homeostasis in human endothelial cells (TeloHAEC). Results showed that treatment for 48 h with PA (0.5 mM) impaired cell viability, induced loss of insulin signaling, imbalanced the oxidative status (p < 0.001), and caused negative modulation of sirtuin protein and mRNA expression, with a predominant effect on SIRT3 (p < 0.001). Restoration of SIRT3 levels by mimic transfection (SIRT3+) suppressed the PA-induced autophagy (mimic NC+PA) (p < 0.01), inflammation, and pyroptosis (p < 0.01) mediated by the NLRP3/caspase-1 axis. Moreover, the unbalanced endothelial redox state induced by PA was counteracted by the antioxidant δ-valerobetaine (δVB), which was able to upregulate protein and mRNA expression of sirtuins, reduce reactive oxygen species (ROS) accumulation, and decrease cell death. Overall, results support the central role of SIRT3 in maintaining the endothelial redox homeostasis under IR and unveil the potential of the antioxidant δVB in enhancing the defense against IR-related injuries

Validation of the Italian version of the Revised Prenatal Coping Inventory (NuPCI) and its correlations with pregnancy-specific stress

Background: Pregnancy is a period of happiness but also of physical and psychological changes that can lead to distress. Functional coping strategies can reduce the pregnancy specific-stress. This study aimed to assess the psychometric properties of the Revised Prenatal Coping Inventory (NuPCI) in an Italian sample and to investigate how coping strategies were associated with pregnancy-specific stress. Methods: In this cross-sectional study, low-risk pregnant women (N = 211) were assessed with NuPCI, NuPDQ (Revised-Prenatal Distress Questionnaire), Brief-COPE (Coping Orientation to the Problems Experienced), and STAI (State-Trait Anxiety Inventory). The reliability of NuPCI was evaluated by assessing its internal consistency and factor structure (with a Confirmatory Factor Analysis, CFA). The concurrent validity between NuPCI and Brief-COPE and NuPDQ and STAI was investigated. Lastly, the relationship between NuPCI and NuPDQ was analyzed, as well as the ability of these scales to predict Apgar score at birth. Results: Internal consistency of NuPCI scales was good for Planning-Preparation (\u251C=0.84) and Spiritual-Positive Coping (\u251C=0.81) scales, acceptable for Avoidance (\u251C=0.76) scale. Moreover, the original three-factor structure was confirmed using a CFA with 29 of the 32 items (\u3c72374 = 618.06; RMSEA = 0.056, 95% confidence interval: [0.048, 0.063]); CFI = 0.920; and TLI = 0.913). Statistically significant correlations between NuPCI scales and Brief-COPE subscales ranged between r = + 0.217 and r = + 0.624; also, NuPDQ score was positively correlated with STAI scales (State scale: r = + 0.539; Trait scale: r = + 0.462). Concurrent validity was confirmed reporting that NuPDQ score was predicted by NuPCI scores (R2 = 0.423, p < 0.001), positively by Avoidance (\u3b2=+0.572) and Planning-Preparation (\u3b2=+0.215) and negatively by Spiritual-Positive Coping (\u3b2=-0.132). Finally, considering the stress, the effect of the Avoidance and Spiritual-Positive Coping scores respectively in decreasing (+ 155%) and increasing (+ 16%) the Apgar score became stronger. Conclusions: Italian NuPCI has sound psychometric properties and it is a useful coping measure. NuPDQ showed also a good validity. Our results may suggest a significant role for coping strategies, particularly in modulating the condition of the newborn at birth

Stochastic finite element analysis of portuguese adobe masonry

Earth is a construction material which has been used since ancient times in many parts of the world according to its local availability, low manufacturing cost, and its need for simple construction techniques. Even though earthen constructions have good thermo-acoustic properties, they typically show a very poor performance under earthquake ground motion. Rammed earth and adobe masonry are the main types of earthen construction. Nowadays, it is estimated that approximately 30% of the world population lives in earthen buildings and this percentage increases up to around 50% in developing countries. Such an information highlights the need for a seismic assessment and strengthening of existing earthen structures. The present study is focused on the mechanical behavior of the traditional adobe masonry (AM) of the Aveiro district, Portugal, where approximately 40% of existing buildings are made of adobe and many of them have a socio-cultural value. Extensive surveys have shown a poor state of conservation of AM buildings, the strengthening of which should be based on a comprehensive knowledge of mechanical properties and behavior. To that aim, a nonlinear finite element (FE) modelling approach is used to simulate the experimental behavior of AM in different boundary and loading conditions associated with axial and diagonal compression tests. The latter are amongst the most common experimental tests used for mechanical characterization of masonry assemblages, particularly to define their macroscopic response to uniaxial compression and shear. Based on statistics for mechanical properties of adobe bricks and mud mortar provided by past experimental tests, a macromechanical model of AM was developed within LS-DYNA software and validated against experimental data. The FE models of two types of specimens subjected to axial compression and diagonal compression, separately, were generated. A comparative analysis between numerical and experimental results, both in terms of force–displacement curves and crack patterns, showed that the FE model was able to reproduce the real behavior of AM in different boundary and loading conditions. Afterwards, a single-parameter sensitivity analysis was performed on each AM model to assess whether and how the AM behavior changes under varying material properties. That analysis was the basis for a probabilistic assessment in which a stochastic FE analysis was carried out. Each material property was assumed to be a spatially-distributed random variable in order to reproduce the high level of inhomogeneity provided by material tests on AM constituents, that is adobe bricks and mortar. A small number of model realizations subjected to axial compression was randomly generated through Monte Carlo simulation technique. Two alternative types of stochastic representation were adopted. The former was a simplified stochastic FE modeling (SFEM) in which the spatial variability of material properties was lumped into single brick units, each of them fictitiously extended to the middle of mortar joints. In the second case, an advanced stochastic FE modeling (ASFEM) strategy was used and consisted in a random generation of material properties for all finite elements. It was found that even a limited number of ASFEM simulations allowed the experimental force–displacement response to be captured

Insight from imaging on plaque vulnerability: similarities and differences between coronary and carotid arteries—implications for systemic therapies

Nowadays it is widely accepted that the rupture of the atherosclerotic plaque in coronary and carotid arteries plays a fundamental role in the development of acute myocardial infarctions or cerebrovascular events. In recent years, imaging techniques have explored, with a new level of detail, the atherosclerotic disease generating new evidences that some plaque characteristics are significantly associated to the risk of rupture and subsequent thrombosis or embolization. Moreover, the recent evidence of the anti-atherosclerotic effects determined by lipid-lowering and anti-inflammatory therapies poses a challenge for the choice of therapeutic approaches (best/optimal medical therapy vs. revascularization), maximized by the evidence that coronary and carotid atherosclerosis share common patterns but also differ regarding some important features. In this Review, we discuss the similarities and differences between coronary and carotid artery vulnerable plaque from the imaging point of view and the potential implications for systemic therapies according to the emerging evidence