Macrobenthic invertebrate energy densities and ecological status in freshwater watercourses (Friuli Venezia-Giulia,Northeast Italy)

The present study provides energy density (ED) data and models for four macrobenthic invertebrate genera inhabiting freshwater lotic environments (Baetis, Hydropsyche, Rhyacophila, and Onychogomphus). Samples were collected in the hydrological freshwater network of the Region Friuli Venezia Giulia within different watercourse types (creeks, streams, rivers channels, and ditches), and energy density was directly measured using an adiabatic bomb calorimeter. Measured ED expressed in Joule g^?1 wet weight was strongly and positively correlated with percentage of dry weight (DW%) for all genera investigated (r²?>?0.9504), allowing to obtain genus-specific predictive models based on the relationship between ED and DW%. Models were validated and showed good predictive power, as 90th percentile of observed percentage errors ranged between 4.23% and 5.18% while medians ranged between 1.32% and 2.83%. ANCOVA disclosed significant differences between the models, as those for Rhyacophila and Onychogomphus differed significantly from the others. The empirical models were used to build a dataset of estimated energy density, to assess the relationship between energy density and ecological status of the monitored riverine systems, assessed in compliance with European and Italian law by the application of four different ecological indices (ICMi, RQE_IBMR, STAR_ICMi, and LIMeco). Information regarding ED levels for freshwater macrobenthic invertebrates is still neglected in biomonitoring programs, but it could be useful to interpret some ecological situations in the context of ecological status assessment, especially in relation to the trophic condition of the investigated riverine systems.

     

Mitochondrial DNA backgrounds might modulate diabetes complications rather than T2DM as a whole

Mitochondrial dysfunction has been implicated in rare and common forms of type 2 diabetes (T2DM). Additionally, rare mitochondrial DNA (mtDNA) mutations have been shown to be causal for T2DM pathogenesis. So far, many studies have investigated the possibility that mtDNA variation might affect the risk of T2DM, however, when found, haplogroup association has been rarely replicated, even in related populations, possibly due to an inadequate level of haplogroup resolution. Effects of mtDNA variation on diabetes complications have also been proposed. However, additional studies evaluating the mitochondrial role on both T2DM and related complications are badly needed. To test the hypothesis of a mitochondrial genome effect on diabetes and its complications, we genotyped the mtDNAs of 466 T2DM patients and 438 controls from a regional population of central Italy (Marche). Based on the most updated mtDNA phylogeny, all 904 samples were classified into 57 different mitochondrial sub-haplogroups, thus reaching an unprecedented level of resolution. We then evaluated whether the susceptibility of developing T2DM or its complications differed among the identified haplogroups, considering also the potential effects of phenotypical and clinical variables. MtDNA backgrounds, even when based on a refined haplogroup classification, do not appear to play a role in developing T2DM despite a possible protective effect for the common European haplogroup H1, which harbors the G3010A transition in the MTRNR2 gene. In contrast, our data indicate that different mitochondrial haplogroups are significantly associated with an increased risk of specific diabetes complications: H (the most frequent European haplogroup) with retinopathy, H3 with neuropathy, U3 with nephropathy, and V with renal failure.     

Physiological roles of mitogen-activated-protein-kinase-activated p38-regulated/activated protein kinase

Mitogen-activated protein kinases (MAPKs) are a family of proteins that constitute signaling pathways involved in processes that control gene expression, cell division, cell survival, apoptosis, metabolism, differentiation and motility. The MAPK pathways can be divided into conventional and atypical MAPK pathways. The first group converts a signal into a cellular response through a relay of three consecutive phosphorylation events exerted by MAPK kinase kinases, MAPK kinase, and MAPK. Atypical MAPK pathways are not organized into this three-tiered cascade. MAPK that belongs to both conventional and atypical MAPK pathways can phosphorylate both non-protein kinase substrates and other protein kinases. The latter are referred to as MAPK-activated protein kinases. This review focuses on one such MAPK-activated protein kinase, MAPK-activated protein kinase 5 (MK5) or p38-regulated/activated protein kinase (PRAK). This protein is highly conserved throughout the animal kingdom and seems to be the target of both conventional and atypical MAPK pathways. Recent findings on the regulation of the activity and subcellular localization, bona fide interaction partners and physiological roles of MK5/PRAK are discussed.     

Single-domain antibodies that compete with the natural ligand fibroblast growth factor block the internalization of the fibroblast growth factor receptor 1

Single-domain antibodies in VHH format specific for fibroblast growth factor receptor 1 (FGFR1) were isolated from a phage-display llama naïve library. In particular, phage elution in the presence of the natural receptor ligand fibroblast growth factor (FGF) allowed for the identification of recombinant antibodies that compete with FGF for the same region on the receptor surface. These antibodies posses a relatively low affinity for FGFR1 and were never identified when unspecific elution conditions favoring highly affine binders were applied to panning procedures. Two populations of competitive antibodies were identified that labeled specifically the receptor-expressing cells in immunofluorescence and recognize distinct epitopes. Antibodies from both populations effectively prevented FGF-dependent internalization and nuclear accumulation of the receptor in cultured cells. This achievement indicates that these antibodies have a capacity to modulate the receptor physiology and, therefore, constitute powerful reagents for basic research and a potential lead for therapeutic applications.     

Identification of a Novel Human Polyomavirus in Organs of the Gastrointestinal Tract

Polyomaviruses are small, non-enveloped viruses with a circular double-stranded DNA genome. Using a generic polyomavirus PCR targeting the VP1 major structural protein gene, a novel polyomavirus was initially identified in resected human liver tissue and provisionally named Human Polyomavirus 12 (HPyV12). Its 5033 bp genome is predicted to encode large and small T antigens and the 3 structural proteins VP1, VP2 and VP3. Phylogenetic analyses did not reveal a close relationship to any known human or animal polyomavirus. Investigation of organs, body fluids and excretions of diseased individuals and healthy subjects with both HPyV12-specific nested PCR and quantitative real-time PCR revealed additional virus-positive samples of resected liver, cecum and rectum tissues and a positive fecal sample. A capsomer-based IgG ELISA was established using the major capsid protein VP1 of HPyV12. Seroprevalences of 23% and 17%, respectively, were determined in sera from healthy adults and adolescents and a pediatric group of children. These data indicate that the virus naturally infects humans and that primary infection may already occur in childhood.     

Torsadogenic Risk of Antipsychotics: Combining Adverse Event Reports with Drug Utilization Data across Europe

Background

Antipsychotics (APs) have been associated with risk of torsade de Pointes (TdP). This has important public health implications. Therefore, (a) we exploited the public FDA Adverse Event Reporting System (FAERS) to characterize their torsadogenic profile; (b) we collected drug utilization data from 12 European Countries to assess the population exposure over the 2005-2010 period.

Methods

FAERS data (2004-2010) were analyzed based on the following criteria: (1) ≥4 cases of TdP/QT abnormalities; (2) Significant Reporting Odds Ratio, ROR [Lower Limit of the 95% confidence interval>1], for TdP/QT abnormalities, adjusted and stratified (Arizona CERT drugs as effect modifiers); (3) ≥4 cases of ventricular arrhythmia/sudden cardiac death (VA/SCD); (4) Significant ROR for VA/SCD; (5) Significant ROR, combined by aggregating TdP/QT abnormalities with VA and SCD. Torsadogenic signals were characterized in terms of signal strength: from Group A (very strong torsadogenic signal: all criteria fulfilled) to group E (unclear/uncertain signal: only 2/5 criteria). Consumption data were retrieved from 12 European Countries and expressed as defined daily doses per 1,000 inhabitants per day (DID).

Results

Thirty-five antipsychotics met at least one criterium: 9 agents were classified in Group A (amisulpride, chlorpromazine, clozapine, cyamemazine, haloperidol, olanzapine, quetiapine, risperidone, ziprasidone). In 2010, the overall exposure to antipsychotics varied from 5.94 DID (Estonia) to 13.99 (France, 2009). Considerable increment of Group A agents was found in several Countries (+3.47 in France): the exposure to olanzapine increased across all Countries (+1.84 in France) and peaked 2.96 in Norway; cyamemazine was typically used only in France (2.81 in 2009). Among Group B drugs, levomepromazine peaked 3.78 (Serbia); fluphenazine 1.61 (Slovenia).

Conclusions

This parallel approach through spontaneous reporting and drug utilization analyses highlighted drug- and Country-specific scenarios requiring potential regulatory consideration: levomepromazine (Serbia), fluphenazine (Slovenia), olanzapine (across Europe), cyamemazine (France). This synergy should be encouraged to support future pharmacovigilance activities.     

Ubiquitination site preferences in anaphase promoting complex/cyclosome (APC/C) substrates

Ordered progression of mitosis requires precise control in abundance of mitotic regulators. The anaphase promoting complex/cyclosome (APC/C) ubiquitin ligase plays a key role by directing ubiquitin-mediated destruction of targets in a temporally and spatially defined manner. Specificity in APC/C targeting is conferred through recognition of substrate D-box and KEN degrons, while the specificity of ubiquitination sites, as another possible regulated dimension, has not yet been explored. Here, we present the first analysis of ubiquitination sites in the APC/C substrate ubiquitome. We show that KEN is a preferred ubiquitin acceptor in APC/C substrates and that acceptor sites are enriched in predicted disordered regions and flanked by serine residues. Our experimental data confirm a role for the KEN lysine as an ubiquitin acceptor contributing to substrate destruction during mitotic progression. Using Aurora A and Nek2 kinases as examples, we show that phosphorylation on the flanking serine residue could directly regulate ubiquitination and subsequent degradation of substrates. We propose a novel layer of regulation in substrate ubiquitination, via phosphorylation adjacent to the KEN motif, in APC/C-mediated targeting.     

Computed Tomography Measurement of Rib Cage Morphometry in Emphysema

Background

Factors determining the shape of the human rib cage are not completely understood. We aimed to quantify the contribution of anthropometric and COPD-related changes to rib cage variability in adult cigarette smokers.

Methods

Rib cage diameters and areas (calculated from the inner surface of the rib cage) in 816 smokers with or without COPD, were evaluated at three anatomical levels using computed tomography (CT). CTs were analyzed with software, which allows quantification of total emphysema (emphysema%). The relationship between rib cage measurements and anthropometric factors, lung function indices, and %emphysema were tested using linear regression models.

Results

A model that included gender, age, BMI, emphysema%, forced expiratory volume in one second (FEV₁)%, and forced vital capacity (FVC)% fit best with the rib cage measurements (R² = 64% for the rib cage area variation at the lower anatomical level). Gender had the biggest impact on rib cage diameter and area (105.3 cm²; 95% CI: 111.7 to 98.8 for male lower area). Emphysema% was responsible for an increase in size of upper and middle CT areas (up to 5.4 cm²; 95% CI: 3.0 to 7.8 for an emphysema increase of 5%). Lower rib cage areas decreased as FVC% decreased (5.1 cm²; 95% CI: 2.5 to 7.6 for 10 percentage points of FVC variation).

Conclusions

This study demonstrates that simple CT measurements can predict rib cage morphometric variability and also highlight relationships between rib cage morphometry and emphysema.     

Does the environment around the H-cluster allow coordination of the pendant amine to the catalytic iron center in [FeFe] hydrogenases? Answers from theory

[FeFe] hydrogenases are H₂-evolving enzymes that feature a diiron cluster in their active site (the [2Fe]_H cluster). One of the iron atoms has a vacant coordination site that directly interacts with H₂, thus favoring its splitting in cooperation with the secondary amine group of a neighboring, flexible azadithiolate ligand. The vacant site is also the primary target of the inhibitor O₂. The [2Fe]_H cluster can span various redox states. The active-ready form (H_ox) attains the Fe^IIFe^I state. States more oxidized than H_ox were shown to be inactive and/or resistant to O₂. In this work, we used density functional theory to evaluate whether azadithiolate-to-iron coordination is involved in oxidative inhibition and protection against O₂, a hypothesis supported by recent results on biomimetic compounds. Our study shows that Fe–N(azadithiolate) bond formation is favored for an Fe^IIFe^II active-site model which disregards explicit treatment of the surrounding protein matrix, in line with the case of the corresponding Fe^IIFe^II synthetic system. However, the study of density functional theory models with explicit inclusion of the amino acid environment around the [2Fe]_H cluster indicates that the protein matrix prevents the formation of such a bond. Our results suggest that mechanisms other than the binding of the azadithiolate nitrogen protect the active site from oxygen in the so-called H _ox ^inact state.     

Hemodynamics of the mouse abdominal aortic aneurysm

The abdominal aortic aneurysm (AAA) is a significant cause of death and disability in the Western world and is the subject of many clinical and pathological studies. One of the most commonly used surrogates of the human AAA is the angiotensin II (Ang II) induced model used in mice. Despite the widespread use of this model, there is a lack of knowledge concerning its hemodynamics; this study was motivated by the desire to understand the fluid dynamic environment of the mouse AAA. Numerical simulations were performed using three subject-specific mouse models in flow conditions typical of the mouse. The numerical results from one model showed a shed vortex that correlated with measurements observed in vivo by Doppler ultrasound. The other models had smaller aneurysmal volumes and did not show vortex shedding, although a recirculation zone was formed in the aneurysm, in which a vortex could be observed, that elongated and remained attached to the wall throughout the systolic portion of the cardiac cycle. To link the hemodynamics with aneurysm progression, the remodeling that occurred between week one and week two of the Ang II infusion was quantified and compared with the hemodynamic wall parameters. The strongest correlation was found between the remodeled distance and the oscillatory shear index, which had a correlation coefficient greater than 0.7 for all three models. These results demonstrate that the hemodynamics of the mouse AAA are driven by a strong shear layer, which causes the formation of a recirculation zone in the aneurysm cavity during the systolic portion of the cardiac waveform. The recirculation zone results in areas of quiescent flow, which are correlated with the locations of the aneurysm remodeling.