Design of Functional Globular β-Sheet Miniproteins

The design of discrete β-sheet peptides is far less advanced than e. g. the design of α-helical peptides. The reputation of β-sheet peptides as being poorly soluble and aggregation-prone often hinders active design efforts. Here, we show that this reputation is unfounded. We demonstrate this by looking at the β-hairpin and WW domain. Their structure and folding have been extensively studied and they have long served as model systems to investigate protein folding and folding kinetics. The resulting fundamental understanding has led to the development of hyperstable β-sheet scaffolds that fold at temperatures of 100 °C or high concentrations of denaturants. These have been used to design functional miniproteins with protein or nucleic acid binding properties, in some cases with such success that medical applications are conceivable. The β-sheet scaffolds are not always completely rigid, but can be specifically designed to respond to changes in pH, redox potential or presence of metal ions. Some engineered β-sheet peptides also exhibit catalytic properties, although not comparable to those of natural proteins. Previous reviews have focused on the design of stably folded and non-aggregating β-sheet sequences. In our review, we now also address design strategies to obtain functional miniproteins from β-sheet folding motifs.

Marine transmissible cancer navigates urbanized waters, threatening spillover

Inter-individual transmission of cancer cells represents a unique form of microparasites increasingly reported in marine bivalves. In this study, we sought to understand the ecology of the propagation of Mytilus trossulus Bivalve Transmissible Neoplasia 2 (MtrBTN2), a transmissible cancer affecting four Mytilus mussel species worldwide. We investigated the prevalence of MtrBTN2 in the mosaic hybrid zone of M. edulis and M. galloprovincialis along the French Atlantic coast, sampling contrasting natural and anthropogenic habitats. We observed a similar prevalence in both species, probably due to the spatial proximity of the two species in this region. Our results showed that ports had higher prevalence of MtrBTN2, with a possible hotspot observed at a shuttle landing dock. No cancer was found in natural beds except for two sites close to the hotspot, suggesting spillover. Ports may provide favourable conditions for the transmission of MtrBTN2, such as high mussel density, stressful conditions, sheltered and confined shores or buffered temperatures. Ships may also spread the disease through biofouling. Our results suggest ports may serve as epidemiological hubs, with maritime routes providing artificial gateways for MtrBTN2 propagation. This highlights the importance of preventing biofouling on docks and ship hulls to limit the spread of marine pathogens hosted by fouling species.

Relationship of Thermostability and Binding Affinity in Metal-binding WW-Domain Minireceptors

The design of metallo-miniproteins advances our understanding of the structural and functional roles of metals in proteins. We recently designed a metal-binding WW domain, WW-CA-Nle, which displays three histidine residues on its surface for coordination of divalent metals Ni(II), Zn(II) and Cu(II). However, WW-CA-Nle is a molten globule in the apo state and thus showed only moderate binding affinities with Kd values in the μM regime. In this report, we hypothesize that improved thermal stability of the apo state of the metal binding WW-domain scaffold should lead to improved preorganization of the metal-binding site and consequently to higher metal-binding affinities. By redesigning WW-CA-Nle, we obtained WW-CA variants, WW-CA-min and WW-CA-ANG, which were fully folded in the apo states and displayed moderate to excellent thermostabilities in the apo and holo states. We were able to show that the improved thermal stabilities led to improved metal binding, which was reflected in Kd values that were at least one order of magnitude lower compared to WW-CA-Nle. EPR spectroscopy and ITC measurements revealed a better defined and predisposed metal binding site in WW-CA-ANG.

Rapid On-Resin N-Formylation of Peptides as One-Pot Reaction

N-formylation is a common pre- and post-translational modification of the N-terminus or the lysine side chain of peptides and proteins that plays a role in the initiation of immune responses, gene expression, or epigenetics. Despite its high biological relevance, protocols for the chemical N-formylation of synthetic peptides are scarce. The few available methods are elaborate in their execution and the yields are highly sequence-dependent. We present a rapid, easy-to-use one-pot procedure that runs at room temperature and can be used to formylate protected peptides at both the N-terminus and the lysine side chain on the resin in near-quantitative yields. Only insensitive, storage-stable standard chemicals - formic acid, acetic anhydride, pyridine and DMF - are used. Formylation works for both short and long peptides of up to 34 amino acids and over the spectrum of canonical amino acids.

Transcriptomics of mussel transmissible cancer MtrBTN2 suggests accumulation of multiple cancer traits and oncogenic pathways shared among bilaterians

Transmissible cancer cell lines are rare biological entities giving rise to diseases at the crossroads of cancer and parasitic diseases. These malignant cells have acquired the amazing capacity to spread from host to host. They have been described only in dogs, Tasmanian devils and marine bivalves. The Mytilus trossulus bivalve transmissible neoplasia 2 (MtrBTN2) lineage has even acquired the capacity to spread inter-specifically between marine mussels of the Mytilus edulis complex worldwide. To identify the oncogenic processes underpinning the biology of these atypical cancers we performed transcriptomics of MtrBTN2 cells. Differential expression, enrichment, protein-protein interaction network, and targeted analyses were used. Overall, our results suggest the accumulation of multiple cancerous traits that may be linked to the long-term evolution of MtrBTN2. We also highlight that vertebrate and lophotrochozoan cancers could share a large panel of common drivers, which supports the hypothesis of an ancient origin of oncogenic processes in bilaterians.

Tritium Beta Spectrum Measurement and Neutrino Mass Limit from Cyclotron Radiation Emission Spectroscopy

The absolute scale of the neutrino mass plays a critical role in physics at every scale, from the subatomic to the cosmological. Measurements of the tritium end-point spectrum have provided the most precise direct limit on the neutrino mass scale. In this Letter, we present advances by Project 8 to the cyclotron radiation emission spectroscopy (CRES) technique culminating in the first frequency-based neutrino mass limit. With only a cm^{3}-scale physical detection volume, a limit of m_{β}<155  eV/c^{2} (152  eV/c^{2}) is extracted from the background-free measurement of the continuous tritium beta spectrum in a Bayesian (frequentist) analysis. Using ^{83m}Kr calibration data, a resolution of 1.66±0.19  eV (FWHM) is measured, the detector response model is validated, and the efficiency is characterized over the multi-keV tritium analysis window. These measurements establish the potential of CRES for a high-sensitivity next-generation direct neutrino mass experiment featuring low background and high resolution.

Impact of renal impairment on dihydropyrimidine dehydrogenase (DPD) phenotyping

BACKGROUND

The chemotherapeutic agent 5-fluorouracil (5-FU) is catabolized by dihydropyrimidine dehydrogenase (DPD), the deficiency of which may lead to severe toxicity or death. Since 2019, DPD deficiency testing, based on uracilemia, is mandatory in France and recommended in Europe before initiating fluoropyrimidine-based regimens. However, it has been recently shown that renal impairment may impact uracil concentration and thus DPD phenotyping.

PATIENTS AND METHODS

The impact of renal function on uracilemia and DPD phenotype was studied on 3039 samples obtained from three French centers. We also explored the influence of dialysis and measured glomerular filtration rate (mGFR) on both parameters. Finally, using patients as their own controls, we assessed as to what extent modifications in renal function impacted uracilemia and DPD phenotyping.

RESULTS

We observed that uracilemia and DPD-deficient phenotypes increased concomitantly to the severity of renal impairment based on the estimated GFR, independently and more critically than hepatic function. This observation was confirmed with the mGFR. The risk of being classified 'DPD deficient' based on uracilemia was statistically higher in patients with renal impairment or dialyzed if uracilemia was measured before dialysis but not after. Indeed, the rate of DPD deficiency decreased from 86.4% before dialysis to 13.7% after. Moreover, for patients with transient renal impairment, the rate of DPD deficiency dropped dramatically from 83.3% to 16.7% when patients restored their renal function, especially in patients with an uracilemia close to 16 ng/ml.

CONCLUSIONS

DPD deficiency testing using uracilemia could be misleading in patients with renal impairment. When possible, uracilemia should be reassessed in case of transient renal impairment. For patients under dialysis, testing of DPD deficiency should be carried out on samples taken after dialysis. Hence, 5-FU therapeutic drug monitoring would be particularly helpful to guide dose adjustments in patients with elevated uracil and renal impairment.

Implementation of dihydropyrimidine dehydrogenase deficiency testing in Europe

BACKGROUND

The main cause for fluoropyrimidine-related toxicity is deficiency of the metabolizing enzyme dihydropyrimidine dehydrogenase (DPD). In 2020, the European Medicines Agency (EMA) recommended two methods for pre-treatment DPD deficiency testing in clinical practice: phenotyping using endogenous uracil concentration or genotyping for DPYD risk variant alleles. This study assessed the DPD testing implementation status in Europe before (2019) and after (2021) the release of the EMA recommendations.

METHODS

The survey was conducted from 16 March 2022 to 31 July 2022. An electronic form with seven closed and three open questions was e-mailed to 251 professionals with DPD testing expertise of 34 European countries. A descriptive analysis was conducted.

RESULTS

We received 79 responses (31%) from 23 countries. Following publication of the EMA recommendations, 87% and 75% of the countries reported an increase in the amount of genotype and phenotype testing, respectively. Implementation of novel local guidelines was reported by 21 responders (27%). Countries reporting reimbursement of both tests increased in 2021, and only four (18%) countries reported no coverage for any testing type. In 2019, major implementation drivers were 'retrospective assessment of fluoropyrimidine-related toxicity' (39%), and in 2021, testing was driven by 'publication of guidelines' (40%). Although the major hurdles remained the same after EMA recommendations-'lack of reimbursement' (26%; 2019 versus 15%; 2021) and 'lack of recognizing the clinical relevance by medical oncologists' (25%; 2019 versus 8%; 2021)-the percentage of specialists citing these decreased. Following EMA recommendations, 25% of responders reported no hurdles at all in the adoption of the new testing practice in the clinics.

CONCLUSIONS

The EMA recommendations have supported the implementation of DPD deficiency testing in Europe. Key factors for successful implementation were test reimbursement and clear clinical guidelines. Further efforts to improve the oncologists' awareness of the clinical relevance of DPD testing in clinical practice are needed.

HAV-peptides attached to colloidal probes faithfully detect E-cadherins displayed on living cells

Cell adhesion molecules are crucial for a variety of biological processes, including wound healing, barrier formationand tissue homeostasis. One of them is E-cadherin which is generally found at adherent junctions between epithelialcells. To identify this molecule on the surface of cells, E-cadherin mimetic peptides with a critical aminoacid sequence of HAV (histidine-alanine-valine) were synthesized and attached to solid supported membranes coveringcolloidal probes. Two different functionalization strategies were established, one based on complexation of DOGSNTA(Ni) with a polyhistidine-tagged HAV-peptide and the other one relying on the formation of a HAV-lipopeptide usingin situ maleimide-thiol coupling. Binding studies were performed to verify the ability of the peptides to attachto the membrane surface. Compared to the non-covalent attachment via the His-tag, we achieved a higher yield bylipopeptide formation. Colloidal probes functionalized with HAV-peptides were employed to measure the presence of Ecadherinson living cells either using video particle tracking or force spectroscopy. Here, human HaCaT cells were examinedconfirming the specific interaction of the HAV-peptide with the E-cadherin of the cells. Statistical methods werealso used to determine the number of single-bond ruptures and the force of a single bond. These findings may be essentialfor the development of novel biosynthetic materials given their potential to become increasingly relevant in medicalapplications.

Discrepancies between Dihydropyrimidine dehydrogenase phenotyping and genotyping: what are the explanatory factors?

AIM

Dihydropyrimidine dehydrogenase (DPD) deficiency can be detected by phenotyping (measurement of plasma uracil (U), with U≥16μg/L defining a partial deficiency) and/or by genotyping (screening for the four most frequent DPYD variants). We aimed to determine the proportion of discrepancies between phenotypic and genotypic approaches and to identify possible explanatory factors.

METHODS

Data from patients who underwent both phenotyping and genotyping were retrospectively collected. Complementary genetic analyses (genotyping of the variant c.557A>G and DPYD sequencing) were performed for patients with U≥16μg/L without any common variants. The characteristics of patients classified according to the congruence of the phenotyping and genotyping approaches were compared (Kruskal-Wallis test) and determinants of U levels were studied in the whole cohort (linear model).

RESULTS

Among the 712 included patients, phenotyping and genotyping were discordant for 12.5%, with 63 (8.8%) having U≥16μg/L in the absence of a common variant. Complementary genetic investigations marginally reduced the percentage of discrepancies to 12.1%: among the nine additional identified variants, only the c.557A>G variant, carried by three patients, had been previously reported to be associated with DPD deficiency. Liver dysfunction could explain certain discordances, as ASAT, ALP, GGT, and bilirubin levels were significantly elevated, with more frequent liver metastases in patients with U≥16μg/L and the absence of a DPYD variant. The impact of cytolysis was confirmed, as ASAT levels were independently associated with increased U (p<0.001).

CONCLUSION

The frequent discordances between DPD phenotyping and genotyping approaches highlight the need to perform these two approaches to screen for all DPD deficiencies.

An Engineered β-Hairpin Peptide Forming Thermostable Complexes with ZnII , NiII , and CuII through a His3 Site

The three-dimensional structure of a peptide, which determines its function, can denature at elevated temperatures, in the presence of chaotropic reagents, or in organic solvents. These factors limit the applicability of peptides. Herein, we present an engineered β-hairpin peptide containing a His₃ site that forms complexes with Zn^II , Ni^II , and Cu^II . Circular dichroism spectroscopy shows that the peptide-metal complexes exhibit melting temperatures up to 80 °C and remain folded in 6 M guanidine hydrochloride as well as in organic solvents. Intrinsic fluorescence titration experiments were used to determine the dissociation constants of metal binding in the nano- to sub-nanomolar range. The coordination geometry of the peptide-Cu^II complex was studied by EPR spectroscopy, and a distorted square planar coordination geometry with weak interactions to axial ligands was revealed. Due to their impressive stability, the presented peptide-metal complexes open up interesting fields of application, such as the development of a new class of peptide-metal catalysts for stereoselective organic synthesis or the directed design of extremophilic β-sheet peptides.

Ultra-sensitive troponin-I and incident coronary heart disease, stroke, heart failure, cardiac arrhythmias, arterial aneurysms and venous thromboembolism hospitalizations

Background

Cardiac troponin I (cTnI) as measured by high-sensitive assays has been related to incident cardiovascular disease events (CVD) in the community. With the advent of ultra-sensitive assays, it is now possible to detect troponin I at very low concentration, far below the classical threshold of 1.9 pg/mL. However, the clinical relevance of these low concentrations for predicting CVD is largely unknown.

Purpose

To examine the association of cTnI as low as 0.013 pg/mL with incident cardiovascular disease events (CVDs) in the primary prevention setting.

Methods

cTnI was analyzed in the baseline plasma (2008–2012) of CVD free volunteers from the Paris Prospective Study III using for the first time a novel ultra-sensitive immunoassay (Simoa Troponin-I 2.0 Kit, Quanterix, Lexington) with a limit of detection (LOD) of 0.013 pg/mL. Incident CVD hospitalizations for coronary heart disease, stroke, arrhythmias, venous thromboembolism, arterial aneurysms and heart failure were validated by critical review of the hospital records. Hazard ratios were estimated per log-transformed standard deviation (SD) increase of cTnI in Cox models using age as the time scale. The added value (gain in discriminatory capacity) of cTnI for CVD risk prediction was examined by calculating the Harell's C-index boostraped difference of the SCORE 2 risk model with and without cTnI.

Results

There were 9503 CVD free participants (40% women) aged 59.6 (6.3) years at baseline. cTnI was detected in 99.6% of the participants (median value = 0.63 pg/mL, interquartile range [IQR] 0.39–1.09). After a median follow-up of 8.34 years (IQR, 8.0–10.07), 516 participants suffered 612 events. In fully-adjusted analysis, higher cTnI (per 1 SD increase of log cTnI) was significantly associated with CVD events combined (n=516, HR= 1.21; 1.06; 1.39). In univariate Cox analysis and compared to each single established risk factor, cTnI had the highest discrimination capacity for incident CVD events (C-index=0.6349) (Figure 1). Adding log cTnI to the SCORE 2 algorithm increased significantly albeit moderately discriminatory capacity (C-index 0.698 vs. 0.685; boostraped C index difference: 0.0135 (95% CI: 0.0131; 0.0138)).

Conclusion

cTnI concentrations as measured by a novel ultra-sensitive immunoassay is associated with a significant increased risk of incident CVD events in the primary prevention setting.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): ANR: French National Research AgencyEurope: Horizon 2020

Healthy sleep score and incident cardiovascular diseases: the Paris Prospective Study III (PPS3)

Background/Introduction

Most studies on the association between sleep habits and cardiovascular disease (CVD) have focused on one single sleep dimension, essentially sleep duration and sleep apnea.

Purpose

To examine the joint effect of several dimensions of sleep habits with incident CVD in a community-based prospective cohort.

Methods

Between 2008 and 2011, 10,157 men and women aged 50 to 75 years were recruited in a preventive medical center. They underwent a standard physical examination coupled with standard biological tests, and provided information related to lifestyle, personal and family medical history, current health status, and medication use on questionnaires. Sleep habits were self-reported on validated questionnaires that assess sleep duration and insomnia complaints (Pittsburg questionnaire), early chronotype, sleep apnea (Berlin questionnaire) and subjective daytime sleepiness (Epworth questionnaire). Each sleep dimension was assigned 1 point if optimal and 0 point otherwise. A healthy sleep score ranging from 0 to 5 (the higher the better) and reflecting the number of optimal sleep dimensions was computed: early chronotype, sleep duration of 7–8 h/day, never/rarely insomnia, no sleep apnea, and no frequent excessive daytime sleepiness. The occurrence of incident CVD events including coronary heart disease and stroke was followed every two years up to September 2020, and events were validated after review of the medical records. The multivariable association between higher healthy sleep score and CVD events was examined in proportional hazard Cox regression analysis. Population-attributable fractions were calculated to estimate the proportion of CVD cases that could be prevented by healthier sleep habits.

Results

This study included 7203 participants (62% of men, mean age: 59.7 years±6.2) who were free of CVD at baseline and had complete data on sleep habits and covariates. Among them, 6.9% had a poor sleep score (healthy sleep score of 0 or 1), and 10.4% had an optimal sleep score (score= 5). After a median follow-up of 8 years, 275 participants had incident CVD events. After adjustment for age, sex, total alcohol consumption, socioprofessional categories, smoking status, body mass index, physical activity, family history of heart diseases, LDL and HDL cholesterol, and diabetes status, the risk of CVD decreased by 22% (HR=0.78 [95% CI: 0.71–0.86]) per 1 point increment in the healthy sleep score, and there was a 74% risk reduction in CVD risk (HR=0.26 [0.13–0.51]) between participants with the highest (score of 5) and those with the lowest (score of 0–1) healthy sleep score (Table 1). Under the hypothesis that all the participants would achieve an optimal sleep score of 5, 70.8% of incident CVD could be potentially avoided each year.

Conclusion(s)

In this community-based prospective cohort, a higher healthy sleep score combining 5 sleep dimensions was associated with a lower risk of CHD or stroke.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The National Research Agency (ANR), The Region Ile de France (Domaine d'Intérêt Majeur)

Adapted educational health program among deprived subjects with prediabetes

AIMS

Assess the feasibility and benefit of a health educational program on global metabolic status in prediabetic deprived subjects.

DESIGN

Case control study.

METHODS

693 subjects (466 men, 227 women), aged 16 to 95 years with prediabetes and low socioeconomic status, consulting at the IPC Center were included between September 2015 and June 2016. Subjects were invited to participate in 4 workshops (2 nutrition, 2 physical activities). One year after their inclusion (visit 1), they were offered a second health check-up (visit 2). Participants were classified into 3 groups: 1) Intervention group (INTG, N=133): complete process 2) Control group (CG, N=415): Only a second health check-up, no workshop participation; 3) Abandoned group (AG, N=145). All groups were compared.

RESULTS

After considered confounding factors, fasting blood glucose and SBP levels variation between visit 1 and visit 2 differed significantly between the CG and INTG. In the INTG with higher diminution of fasting glucose, 90% reported eating healthy food since nutrition workshop and 51%. reached objectives (The same trend was observed for physical activity.

CONCLUSION

An educational program among deprived prediabetic tended to limit fasting glucose increment, improve metabolic status and encourage healthy lifestyle despite difficulties in convincing subjects to participate.

Late‐Stage Functionalisation of Peptides on the Solid Phase by an Iodination‐Substitution Approach

The functionalisation of peptides at a late synthesis stage holds great potential, for example, for the synthesis of peptide pharmaceuticals, fluorescent biosensors or peptidomimetics. Here we describe an on‐resin iodination‐substitution reaction sequence on homoserine that is also suitable for peptide modification in a combinatorial format. The reaction sequence is accessible to a wide range of sulfur nucleophiles with various functional groups including boronic acids, hydroxy groups or aromatic amines. In this way, methionine‐like thioethers or thioesters and thiosulfonates are accessible. Next to sulfur nucleophiles, selenols, pyridines and carboxylic acids were successfully used as nucleophiles, whereas phenols did not react. The late‐stage iodination‐substitution approach is not only applicable to short peptides but also to the more complex 34‐amino‐acid WW domains. We applied this strategy to introduce 7‐mercapto‐4‐methylcoumarin into a switchable Zn^II responsive WW domain to design an iFRET‐based Zn^II sensor.

Transmissible cancer influences immune gene expression in an endangered marsupial, the Tasmanian devil (Sarcophilus harrisii)

Understanding the effects of wildlife diseases on populations requires insight into local environmental conditions, host defence mechanisms, host life‐history trade‐offs, pathogen population dynamics, and their interactions. The survival of Tasmanian devils (Sarcophilus harrisii) is challenged by a novel, fitness limiting pathogen, Tasmanian devil facial tumour disease (DFTD), a clonally transmissible, contagious cancer. In order to understand the devils’ capacity to respond to DFTD, it is crucial to gain information on factors influencing the devils’ immune system. By using RT‐qPCR, we investigated how DFTD infection in association with intrinsic (sex and age) and environmental (season) factors influences the expression of 10 immune genes in Tasmanian devil blood. Our study showed that the expression of immune genes (both innate and adaptive) differed across seasons, a pattern that was altered when infected with DFTD. The expression of immunogbulins IgE and IgM:IgG showed downregulation in colder months in DFTD infected animals. We also observed strong positive association between the expression of an innate immune gene, CD16, and DFTD infection. Our results demonstrate that sampling across seasons, age groups and environmental conditions are beneficial when deciphering the complex ecoevolutionary interactions of not only conventional host‐parasite systems, but also of host and diseases with high mortality rates, such as transmissible cancers.

Switchable Zinc(II)-Responsive Globular β-Sheet Peptide

The natural function of many proteins depends on their ability to switch their conformation driven by environmental changes. In this work, we present a small, monomeric β-sheet peptide that switches between a molten globule and a folded state through Zn(II) binding. The solvent-exposed hydrophobic core on the β-sheet surface was substituted by a His₃-site, whereas the internal hydrophobic core was left intact. Zn(II) is specifically recognized by the peptide relative to other divalent metal ions, binds in the lower micromolar range, and can be removed and re-added without denaturation of the peptide. In addition, the peptide is fully pH-switchable, has a pK_a of about 6, and survives several cycles of acidification and neutralization. In-depth structural characterization of the switch was achieved by concerted application of circular dichroism (CD) and multinuclear NMR spectroscopy. Thus, this study represents a viable approach toward a globular β-sheet Zn(II) mini-receptor prototype.

The CSY-protecting group in the microwave-assisted synthesis of aggregation-prone peptides

This report describes the application of cyanosulfurylide (CSY)-protected aspartatic acid building blocks in microwave-assisted synthesis of aggregation-prone protein domains. We present a synthesis of Fmoc-Asp(CSY)-OH on a multigram scale, as...

Identification of novel functional mini-receptors by combinatorial screening of split-WW domains

A combinatorial approach toward novel functional WW domains based on coiled-coil-mediated reconstitution of split WW domains is presented. As such, an ATP-binding WW domain was found from a 4-by-6 library of N- and C-terminal WW domain fragments.

Traits of a mussel transmissible cancer are reminiscent of a parasitic life style

Some cancers have evolved the ability to spread from host to host by transmission of cancerous cells. These rare biological entities can be considered parasites with a host-related genome. Still, we know little about their specific adaptation to a parasitic lifestyle. MtrBTN2 is one of the few lineages of transmissible cancers known in the animal kingdom. Reported worldwide, MtrBTN2 infects marine mussels. We isolated MtrBTN2 cells circulating in the hemolymph of cancerous mussels and investigated their phenotypic traits. We found that MtrBTN2 cells had remarkable survival capacities in seawater, much higher than normal hemocytes. With almost 100% cell survival over three days, they increase significantly their chances to infect neighboring hosts. MtrBTN2 also triggered an aggressive cancerous process: proliferation in mussels was ~ 17 times higher than normal hemocytes (mean doubling time of ~ 3 days), thereby favoring a rapid increase of intra-host population size. MtrBTN2 appears to induce host castration, thereby favoring resources re-allocation to the parasites and increasing the host carrying capacity. Altogether, our results highlight a series of traits of MtrBTN2 consistent with a marine parasitic lifestyle that may have contributed to the success of its persistence and dissemination in different mussel populations across the globe.

Oral Condition and Incident Coronary Heart Disease: A Clustering Analysis

Poor oral health has been linked to coronary heart disease (CHD). Clustering clinical oral conditions routinely recorded in adults may identify their CHD risk profile. Participants from the Paris Prospective Study 3 received, between 2008 and 2012, a baseline routine full-mouth clinical examination and an extensive physical examination and were thereafter followed up every 2 y until September 2020. Three axes defined oral health conditions: 1) healthy, missing, filled, and decayed teeth; 2) masticatory capacity denoted by functional masticatory units; and 3) gingival inflammation and dental plaque. Hierarchical cluster analysis was performed with multivariate Cox proportional hazards regression models and adjusted for age, sex, smoking, body mass index, education, deprivation (EPICES score; Evaluation of Deprivation and Inequalities in Health Examination Centres), hypertension, type 2 diabetes, LDL and HDL serum cholesterol (low- and high-density lipoprotein), triglycerides, lipid-lowering medications, NT-proBNP and IL-6 serum level. A sample of 5,294 participants (age, 50 to 75 y; 37.10% women) were included in the study. Cluster analysis identified 3,688 (69.66%) participants with optimal oral health and preserved masticatory capacity (cluster 1), 1,356 (25.61%) with moderate oral health and moderately impaired masticatory capacity (cluster 2), and 250 (4.72%) with poor oral health and severely impaired masticatory capacity (cluster 3). After a median follow-up of 8.32 y (interquartile range, 8.00 to 10.05), 128 nonfatal incident CHD events occurred. As compared with cluster 1, the risk of CHD progressively increased from cluster 2 (hazard ratio, 1.45; 95% CI, 0.98 to 2.15) to cluster 3 (hazard ratio, 2.47; 95% CI, 1.34 to 4.57; P < 0.05 for trend). To conclude, middle-aged individuals with poor oral health and severely impaired masticatory capacity have more than twice the risk of incident CHD than those with optimal oral health and preserved masticatory capacity (ClinicalTrials.gov NCT00741728).

Lanthanide complexes of DOTA-nitroxide conjugates for redox imaging: spectroelectrochemistry, CEST, relaxivity, and cytotoxicity

The lanthanide(iii) complexes (Gd, Eu, Dy, and Yb) of DOTA tris(amide) and bis(amide) derivatives (L₁ and L₂) featuring one redox active TEMPO arm were prepared. Ligand L₂ harbours an alkyne fragment for further functionalization. The X-ray crystal structure of ligand L₂ in complexation with Na⁺ was solved. The complexes showed in their CV one oxidation wave (0.26-0. 34 V vs. Fc⁺/Fc) due to an oxoammonium/nitroxide redox couple and a broad reduction corresponding to the nitroxide/hydroxylamine system. The Eu complexes demonstrated the presence of one water molecule in their coordination sphere. The nitroxide complexes were characterized by EPR spectroscopy, showing the typical 3-line pattern in the high temperature regime, which is quenched upon the addition of ascorbate (reduction into hydroxylamine). In their nitroxide form, the complexes show essentially no CEST peak. Conversely, the reduced complexes demonstrate a 12% CEST peak at 51 ppm, corresponding to the metal bound water molecule. Fast exchange precluded the CEST activity for the amide protons. All the complexes proved to be essentially non-toxic for M21 cells at concentrations up to 50 μM.

Prediabetes and deprivation: A couple at high risk of diabetes

AIM

The higher prevalence of diabetes in deprived populations is well documented but little is known about the risk of diabetes associated with deprivation among pre-diabetic subjects. The aim of the study was to evaluate the risk of diabetes in a population of deprived pre-diabetic patients.

METHODS

2743 pre-diabetic subjects identified using the American Diabetes Association (ADA) criteria, 16 to 85 years old, 1656 non-deprived and 1087 deprived, had at least two health check-ups at an interval of 4.95 (2.04) vs 3.20 (1.71) years, P<0.0001, respectively. At the first visit, socioeconomic status was assessed using the EPICES score to differentiate deprived and non-deprived subjects.

RESULTS

At the second visit, the prevalence of overt diabetes was 9.5% among deprived vs 5.1% in the non-deprived group (P<0.001). After adjustment on confounding factors, deprivation was found independently associated with occurrence of diabetes [1.70 (1.15-2.51), P=0.01]. Beyond social deprivation, Fasting Plasma Glucose and waist circumference were the main independent predictors of new-onset diabetes.

CONCLUSION

After 4 years of follow-up, among subjects with prediabetes, prevalence of diabetes was twice as high among deprived compared with non-deprived subjects. Deprived populations with pre-diabetes may require specific public health approaches to avoid the occurrence of overt diabetes.

Effect of Methionine Sulfoxide on the Synthesis and Purification of Aggregation-Prone Peptides

A two-step synthesis for methionine-containing hydrophobic and/or aggregation-prone peptides is presented that takes advantage of the reversibility of methionine oxidation. The use of polar methionine sulfoxide as a building block in solid-phase peptide synthesis improves the synthesis quality and yields the crude peptide, with significantly improved solubility compared to the reduced species. This facilitates the otherwise often laborious peptide purification by high-performance liquid chromatography. The subsequent reduction proceeds quantitatively. This approach has been optimised with the methionine-rich Tar-DNA-binding protein 43 (307-347), but is also more generally applicable, as demonstrated by the syntheses of human calcitonin and two aggregation-prone peptides from the human prion protein.

Building resilience to early life trauma in belarus and Ukraine

Abstract Body

Early life trauma (ELT) refers to various types of adversity that occur during the early years (usually defined as the first 5 years) of a person’s life. It is a key determinant of mental health and well-being throughout the life course. A series of three workshops on early life trauma and mental health care were conducted in Belarus and Ukraine in 2018-2019 to support stakeholders and service providers to better understand and respond to ELT, and to support the development of a network of ELT specialists dedicated to finding common goals, pooling cross-disciplinary data and sharing experiences and good practice across countries. The workshops found that different attitudes, expectations and experiences amongst stakeholders and service providers could hinder the development of consistent, effective and empowering care in Belarus and Ukraine. However, opportunities for more protective and health-enhancing responses were also identified, including the need for: evidence-based education and training; clear roles and communication pathways across sectors; and inter-sectoral partnerships and networks to leverage resources, mitigate practitioner burnout, and build a continuum of support within communities. Findings have been disseminated through a directory of resources in Belarus, a project webpage (www.earlylifetrauma.info) and a report on ELT in Belarus and Ukraine published by WHO Europe.

Disclosure

No significant relationships.

• Impact of relative mental illness on caregivers

Introduction

Belarus is undergoing legislative shifts towards community-based mental health care. Responding effectively to support this process requires an understanding of the experiences and challenges facing families caring for a relative affected by mental illness.

Objectives

To identify how caring for a person with severe mental illness impacts on family carers, and what carers identify as their support needs.

Methods

Semi-structured interviews were undertaken with 17 caregivers of people affected by severe mental illness (diagnosis of F06.8, F20, F25, F7, and/or F 84) in Belarus between March - June 2019.

Results

Care-giving for a family member was usually undertaken on a full time basis with no option for respite. Whilst caring did, in cases, strengthen family solidarity, it also resulted in intensive stress and burnout, financial pressures, and high levels of family tension, exacerbated when the person living with mental illness was perceived as a potential safety risk. High levels of societal stigma meant that care-givers commonly felt unable to discuss their circumstances, travel in public spaces, or participate in community activities. Stigma also deterred carers from seeking professional support. Priorities for support amongst carers included better information, public awareness raising and sensitization, advocacy to support patient integration into social and economic life, peer support and respite for family carers, and an increase in mental health specialists.

Conclusions

Caregiving affected family carers on multiple levels with predominantly negative consequences. Priorities identified by carers need to be considered and acted upon if community-based care is to become an effective option.

Distorted copper(ii) radicals with sterically hindered salens: electronic structure and aerobic oxidation of alcohols

The sterically hindered salen ligands featuring biphenyl and tetramethyl putrescine linkers were synthesized and chelated to copper. The resulting complexes CuL^bp,tBu, CuL^bp,OMe, CuL^pu,tBu and CuL^pu,OMe were structurally characterized, showing a significanty tetrahedrally distorted metal center. The complexes show two reversible oxidation waves in the range 0.2 to 0.8 V vs. Fc⁺/Fc. A further reduction wave is detected in the range -1.4 to -1.7 V vs. Fc⁺/Fc. It is reversible for CuL^bp,tBu and CuL^bp,OMe and assigned to the Cu^II/Cu^I redox couple. One-electron oxidation of CuL^bp,OMe, CuL^pu,tBu and CuL^pu,OMe was performed chemically and electrochemically. It is accompanied by a quenching of the EPR resonances. Phenoxyl radical formation was established by X-Ray diffraction on the cations [CuL^bp,OMe]⁺ and [CuL^pu,OMe]⁺, whereby the coordination sphere is elongated upon oxidation with quinoidal distributions of bond distances. The cations exhibit a NIR band of moderate intensity in their optical spectrum, supporting their classification as class II mixed-valent radical species according to the Robin Day classification. The proposed electronic structures are supported by DFT calculations. The cations [CuL^bp,OMe]⁺, [CuL^pu,tBu]⁺ and [CuL^pu,OMe]⁺ were active towards aerobic oxidation of the unactivated alcohol 2-phenylethanol, with TON numbers up to 58 within 3 h.

Acute and Post-Traumatic Stress Disorders: A biased nervous system

Acute stress disorder and post-traumatic stress disorder are generally triggered by an exceptionally intense threat. The consequences of this traumatogenic situation are explored here in chronological order, from exposure to the threat to development of symptoms. Such a situation may disrupt the equilibrium between two fundamental brain circuits, referred to as the "defensive" and "cognitive". The defensive circuit triggers the stress response as well as the formation of implicit memory. The cognitive circuit triggers the voluntary response and the formation of explicit autobiographical memory. During a traumatogenic situation, the defensive circuit could be over-activated while cognitive circuit is under-activated. In the most severe cases, overactivation of the defensive circuit may cause its brutal deactivation, resulting in dissociation. Here, we address the underlying neurobiological mechanisms at every scale: from neurons to behaviors, providing a detailed explanatory model of trauma.

Neither Cathodal nor Anodal Transcranial Direct Current Stimulation on the Left Dorsolateral Prefrontal Cortex alone or Applied During Moderate Aerobic Exercise Modulates Executive Function

There is converging evidence that both aerobic exercise (AE) and transcranial direct current stimulation (tDCS) can acutely modulate executive functions (EF). In addition, recent studies have proposed the beneficial effects of applying tDCS during AE on physical performance. This study aimed to investigate whether tDCS applied during an AE session additionally or differently effects EF. Therefore, five experiments were conducted in a counterbalanced pre-post-retention crossover design to explore the acute effects of tDCS and AE on EF (inhibition and updating) once in isolation (i.e., either cathodal, anodal tDCS or AE alone as controls) and once in a combined application (i.e., anodal and cathodal tDCS during AE versus sham tDCS during AE). No differences were found in any experiment in the cognitive test parameters. However, in the case of anodal tDCS vs. sham during AE, heart rate was significantly affected. For cathodal tDCS vs. sham during AE, a significant Anova interaction indicated that cathodal tDCS during AE slightly reduced ratings of perceived exertion. The nonsignificant effects of tDCS on EFs are in contrast to previous studies, as no replication of existing observations could be achieved. Thus, the protocol applied in this study does not provide any strong evidence that a combination of AE and tDCS has any effects on EFs, but indicates effects on physiological parameters and subjective exhaustion ratings. Further research should consider changes in AE and tDCS parameters (e.g., intensity or exercise mode) and sequence of applications (online vs. offline).

Structural and spectroscopic investigations of nine-coordinate redox active lanthanide complexes with a pincer O,N,O ligand

The lanthanide complexes EuL3, GdL3, YbL3 and LuL3 of the N,N'-bis(2-hydroxy-di-3,5-tert-butylphenyl)amine were prepared. The X-Ray crystal structures of GdL3 and LuL3 demonstrated a nine-coordinate sphere with three ligand molecules under their anionic diamagnetic form (Cat-N-BQ)-. The complexes showed three oxidation events (Eox11/2 = 0.15-0.16 V, E1/22 = 0.51-55 V, and E1/23 = 0.75-0.78 V vs. Fc+/Fc) via cyclic voltammetry, corresponding to the successive oxidation of the aminophenolate moeities to iminosemiquinone species. The complexes GdL3 and YbL3 were characterized by EPR spectroscopy, allowing for the determination of the zero field splitting (ZFS) parameters in the first case. The monocations (LnL3)+ and monoanions (LnL3)- were electrochemically generated (Ln = Eu, Gd, Yb, Lu), as well as the dications YbL32+ and LuL32+. The spins are antiferromagnetically exchange coupled in the diradical species LuL32+ (|D| = 260 MHz, E = 0). All the complexes (incl. neutral) possess a strong absorption band in the NIR region (730-840 nm, ε > 19 mM-1 cm-1) corresponding to ligand-based transitions.

The influence of prompts on final year medical students' learning process and achievement in ECG interpretation

Objective: ECG interpretation is prone to errors that can lead to relevant misdiagnoses and incorrect treatment. Prompts are one way in lectures to encourage learning from one's own mistakes and to reduce error rates. Prompts are measures such as questions, hints, and suggestions of content-related or metacognitive nature, which can lead to self-explanation in the learner and thus to a deeper understanding of an issue. The aim of the study was therefore to investigate whether the use of prompts can reduce the error rate in ECG interpretation among students. Method: In a 2x2 experimental test and control group design, N=100 final year medical students carried out ECG interpretation tasks in the form of online case vignettes in CASUS^®. In these tasks, justification prompts (B) and error analysis prompts (F) were systematically varied in four groups and the learning success was measured using a knowledge test. In addition, prior knowledge in ECG interpretation, motivation, interest in the topic, subjective confidence in ECG interpretation, and cognitive load was collected. Results: Neither error analysis prompts nor justification prompts had a significant effect on the correct ECG interpretation by students, F(1,96)=1.03, p=.31. Justification prompts seemed to have a positive effect on the confidence of answering the questions, F(1,96)=10.15, p=.002, partial η² =.10; and a negative effect on student motivation, F(1,96)=8.13 , p=.005, partial η² =.08; but both with comparable diagnostic accuracy. Conclusion: The present study could not confirm the positive effects of prompts on the error rate in ECG interpretation reported in the literature but showed significant effects on subjective confidence and motivation which should be investigated in further studies.

Masticatory Capacity and Mortality: The Preventive and Clinical Investigation Center (IPC) Cohort Study

Poor oral health (OH) has been associated with mortality, but the association between OH components and mortality remains imprecise. The present observational study aimed to investigate if there is an association between oral masticatory efficiency and cardiovascular (CV) mortality in a large French subject cohort. The study was based on a cohort of 85,830 subjects aged between 16 and 94 y at recruitment. The follow-up extended from 2001 to 2014 and the mean follow-up was 8.06 ± 2.73 y. The number of deaths totaled 1,670. Full-mouth examinations were performed. Dental plaque, dental calculus, gingival inflammation, missing teeth, and masticatory units were recorded. Masticatory units represent the number of natural or prosthetic opposing premolars and molar pairs and can be considered an accurate indicator for masticatory efficiency. Causes of death were ascertained from death certificates. Cox regression analyses were used to calculate hazard ratios (HRs). In the fully adjusted model, the number of masticatory units <5 is associated with an HR of 1.72 (95% confidence interval [CI], 1.54 to 1.91) for all-cause mortality, HR of 1.41 (95% CI, 1.01 to 1.99) for CV mortality, HR of 1.76 (95% CI, 1.44 to 2.15) for cancer mortality, and HR of 1.85 (95% CI, 1.55 to 2.20) for non-CV and noncancer mortality. Significant statistical associations with the other oral variables were also found for all-cause mortality, cancer mortality, and non-CV and noncancer mortality in the adjusted models. Our study indicates that after full adjustment, all oral parameters are associated with all-cause, cancer, and non-CV and noncancer mortality. However, the low number of masticatory units is associated with an increased risk of CV mortality. We highlight the association of masticatory units and CV mortality.

Determination of Cry9C Protein in Corn-Based Foods by Enzyme-Linked Immunosorbent Assay: Interlaboratory Study

The performance of a commercially available enzyme-linked immunosorbent assay kit (Enviro-Logix) was assessed for the determination of Cry9C protein, which is produced by the genetically modified corn StarLink, in 8 types of corn-based foods (starch, refined oil, soft tortillas, tortilla chips, corn flakes, corn puffs, corn muffins, and corn bread) in an interlaboratory study involving 7 laboratories in the United States. The assay kit is a double antibody sandwich and is based on the specific interaction between antibody and antigen. The Cry9C protein analyte is sandwiched between 2 antibodies, one to capture the analyte and the other is conjugated to the enzyme, horseradish peroxidase. The enzyme uses tetramethylbenzidine/peroxide for color development. A strong acid stopping reagent is then used to change the color from blue to a stable yellow. The intensity of the color is proportional to the concentration of the Cry9C protein. In this study blind duplicates of control samples (blank material prepared from non- StarLink corn), spiked samples (blank material with the addition of Cry9C protein), and samples containing incurred analyte (products prepared with StarLink corn) were analyzed. Cry9C protein from 2 different sources was used to spike the food products. Cry9C protein produced and purified from a bacterial host was used to prepare spiked test samples at 2.72 and 6.8 ng/g. Cry9C protein from StarLink corn flour was used to prepare spiked samples at 1.97 ng/g. Average recoveries for samples spiked with corn flour Cry9C protein at 1.97 ng/g ranged from 73 to 122%, within-laboratory relative standard deviations (RSDr) ranged from 6 to 22%, and between-laboratories relative standard deviations (RSDR) ranged from 16 to 56%. Average recoveries for samples spiked with bacterial Cry9C protein at 2.72 and 6.8 ng/g ranged from 27 to 96% and from 32 to 113%, respectively; RSDr values ranged from 10 to 35%and from 7 to 38%, respectively; and the RSDR ranged from 28 to 84%and 15 to 75%, respectively. The incurred test samples were found to contain Cry9C protein at levels ranging from 0.8 to 3187 ng/g depending on the product, RSDr values ranged from 5 to 16% and RSDR values ranged from 11 to 71%. Results of the statistical analysis indicate that this method is applicable to the determination of Cry9C protein in the 8 types of collaboratively studied corn-based products containing Cry9C protein (from StarLink ) at levels of ≥2 ng/g.

Guiding Biomolecular Interactions in Cells Using de Novo Protein-Protein Interfaces

An improved ability to direct and control biomolecular interactions in living cells would have an impact on synthetic biology. A key issue is the need to introduce interacting components that act orthogonally to endogenous proteomes and interactomes. Here, we show that low-complexity, de novo designed protein-protein interaction (PPI) domains can substitute for natural PPIs and guide engineered protein-DNA interactions in Escherichia coli. Specifically, we use de novo homo- and heterodimeric coiled coils to reconstitute a cytoplasmic split adenylate cyclase, recruit RNA polymerase to a promoter and activate gene expression, and oligomerize both natural and designed DNA-binding domains to repress transcription. Moreover, the stabilities of the heterodimeric coiled coils can be modulated by rational design and, thus, adjust the levels of gene activation and repression in vivo. These experiments demonstrate the possibilities for using designed proteins and interactions to control biomolecular systems such as enzyme cascades and circuits in cells.

Body Silhouette Trajectories Over the Lifespan and Insomnia Symptoms: The Paris Prospective Study 3

Insomnia symptoms are highly prevalent and associated with several adverse medical conditions, but only few determinants, including non-modifiable ones, have been highlighted. We investigated associations between body silhouette trajectories over the lifespan and insomnia symptoms in adulthood. From a community-based study, 7 496 men and women aged 50–75 years recalled their body silhouette at age 8, 15, 25, 35 and 45, and rated the frequency of insomnia symptoms on a standardized sleep questionnaire. An Epworth Sleepiness Scale ≥11 defined excessive daytime sleepiness (EDS). Using a group-based trajectory modeling, we identified five body silhouette trajectories: a ‘lean-stable’ (32.7%), a ‘heavy-stable’ (8.1%), a ‘moderate-stable’ (32.5%), a ‘lean-increase’ (11%) and a ‘lean-marked increase’ (15.7%) trajectory. In multivariate logistic regression, compared to the ‘lean-stable’ trajectory, the ‘lean-marked increase’ and ‘heavy-stable’ trajectories were associated with a significant increased odd of having ≥1 insomnia symptoms as compared to none and of having a proxy for insomnia disorder (≥1 insomnia symptom and EDS). The association with the ‘lean-marked increase' trajectory’ was independent from body mass index measured at study recruitment. In conclusion, increasing body silhouette over the lifespan is associated with insomnia symptoms in adulthood, emphasizing the importance of weight gain prevention during the entire lifespan.

Decoration of Coiled-Coil Peptides with N-Cysteine Peptide Thioesters As Cyclic Peptide Precursors Using Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC) Click Reaction

The development of a copper-catalyzed azide-alkyne cycloaddition (CuAAC) protocol for the decoration of coiled coils with N-cysteine peptide thioesters as cyclic peptide precursors is presented. The reaction conditions include tert-butanol/PBS as the solvent and CuSO₄/THPTA/ascorbate as the catalytic system. During these studies, partial formylation of N-terminal cysteine peptides is observed. Mechanistic analysis leads to identification of the formyl source and, hence, to the development of reaction conditions, under which the undesired side reaction was suppressed.

Differences in health outcomes associated with initial adherence to oral antidiabetes medications among veterans with uncomplicated Type 2 diabetes: a 5-year survival analysis

AIM

To determine the association of adherence to oral antidiabetes medication with macrovascular and microvascular complications, time to insulin therapy, revascularization, admissions, and death among veterans with uncomplicated diabetes.

METHODS

This was a retrospective cohort study using the Veterans Affairs Corporate Data Warehouse to examine 159 032 veterans diagnosed with uncomplicated diabetes during 2002-2014 and starting oral antidiabetes therapy for the first time. The first uncomplicated diabetes diagnosis was identified and confirmed by subsequent oral antidiabetes therapy initiation. Adherence was calculated from outpatient pharmacy records using the proportion of days covered over the first year of therapy. Health outcomes were observed up to 5 years beyond the first oral antidiabetes agent fill, and compared according to adherence status using Cox proportional hazards models adjusted for baseline demographic and clinical characteristics.

RESULTS

During the first 5 years of oral antidiabetes treatment, people initially non-adherent to oral antidiabetes therapy were more likely to experience myocardial infarction (hazard ratio 1.14, 95% CI 1.03-1.27) and ischaemic stroke (hazard ratio 1.22, 95% CI 1.05-0.1.42), or to die (hazard ratio 1.21; 95% CI 1.15-1.28). Veterans with <20% adherence to oral antidiabetes therapy in the first year had particularly high hazards for ischaemic stroke (hazard ratio 1.78, 95% CI 1.27-2.49) and all-cause death (hazard ratio 1.33, 95% CI 1.17-151). Adherent people were more likely to be diagnosed with a microvascular complication or chronic kidney disease.

CONCLUSIONS

People who are non-adherent to treatment were more likely to experience detrimental health outcomes within the first 5 years of antidiabetes therapy. Adherence is paramount to disease management and this should be stressed from the time at which treatment is initiated.