Local structural preferences in shaping tau amyloid polymorphism.

Tauopathies encompass a group of neurodegenerative disorders characterised by diverse tau amyloid fibril structures. The persistence of polymorphism across tauopathies suggests that distinct pathological conditions dictate the adopted polymorph for each disease. However, the extent to which intrinsic structural tendencies of tau amyloid cores contribute to fibril polymorphism remains uncertain.

Exploiting the aggregation propensity of beta-lactamases to design inhibitors that induce enzyme misfolding.

There is an arms race between beta-lactam antibiotics development and co-evolving beta-lactamases, which provide resistance by breaking down beta-lactam rings. We have observed that certain beta-lactamases tend to aggregate, which persists throughout their evolution under the selective pressure of antibiotics on their active sites. Interestingly, we find that existing beta-lactamase active site inhibitors can act as molecular chaperones, promoting the proper folding of these resistance factors.

Exploiting the intrinsic misfolding propensity of the KRAS oncoprotein.

Mutant KRAS is a major driver of oncogenesis in a multitude of cancers but remains a challenging target for classical small molecule drugs, motivating the exploration of alternative approaches. Here, we show that aggregation-prone regions (APRs) in the primary sequence of the oncoprotein constitute intrinsic vulnerabilities that can be exploited to misfold KRAS into protein aggregates. Conveniently, this propensity that is present in wild-type KRAS is increased in the common oncogenic mutations at positions 12 and 13.

Seeding, maturation and propagation of amyloid β-peptide aggregates in Alzheimer's disease.

Alzheimer's disease is neuropathologically characterized by the deposition of the amyloid β-peptide (Aβ) as amyloid plaques. Aβ plaque pathology starts in the neocortex before it propagates into further brain regions. Moreover, Aβ aggregates undergo maturation indicated by the occurrence of post-translational modifications.

Mapping the sequence specificity of heterotypic amyloid interactions enables the identification of aggregation modifiers.

Heterotypic amyloid interactions between related protein sequences have been observed in functional and disease amyloids. While sequence homology seems to favour heterotypic amyloid interactions, we have no systematic understanding of the structural rules determining such interactions nor whether they inhibit or facilitate amyloid assembly. Using structure-based thermodynamic calculations and extensive experimental validation, we performed a comprehensive exploration of the defining role of sequence promiscuity in amyloid interactions.

A three-step support strategy for relatives of patients dying in the intensive care unit: a cluster randomised trial.

Background: In relatives of patients dying in intensive care units (ICUs), inadequate team support can increase the prevalence of prolonged grief and other psychological harm. We aimed to evaluate whether a proactive communication and support intervention would improve relatives' outcomes.

Methods: We undertook a prospective, multicentre, cluster randomised controlled trial in 34 ICUs in France, to compare standard care with a physician-driven, nurse-aided, three-step support strategy for families throughout the dying process, following a decision to withdraw or withhold life support.

Heterotypic Amyloid β interactions facilitate amyloid assembly and modify amyloid structure.

It is still unclear why pathological amyloid deposition initiates in specific brain regions or why some cells or tissues are more susceptible than others. Amyloid deposition is determined by the self-assembly of short protein segments called aggregation-prone regions (APRs) that favour cross-β structure. Here, we investigated whether Aβ amyloid assembly can be modified by heterotypic interactions between Aβ APRs and short homologous segments in otherwise unrelated human proteins.

Synthetic Pept-Ins as a Generic Amyloid-Like Aggregation-Based Platform for PET Imaging of Intracellular Targets.

Amyloid-like aggregation of proteins is induced by short amyloidogenic sequence segments within a specific protein sequence resulting in self-assembly into β-sheets. We recently validated a technology platform in which synthetic amyloid peptides ("Pept-ins") containing a specific aggregation-prone region (APR) are used to induce specific functional knockdown of the target protein from which the APR was derived, including bacterial, viral, and mammalian cell proteins. In this work, we investigated if Pept-ins can be used as vector probes for Positron Emission Tomography (PET) imaging of intracellular targets.

Subcostal versus transhepatic view to assess the inferior vena cava in critically ill patients.

Background: Evaluation of the inferior vena cava (IVC) is not always possible through the subcostal (SC) window.

Methods: Inferior vena cava diameters measured by transhepatic (TH) and SC views were compared by Bland and Altman analysis.

Results: 131 patients were enrolled, including 88 (67%) under mechanical ventilation.

Reverse engineering synthetic antiviral amyloids.

Human amyloids have been shown to interact with viruses and interfere with viral replication. Based on this observation, we employed a synthetic biology approach in which we engineered virus-specific amyloids against influenza A and Zika proteins. Each amyloid shares a homologous aggregation-prone fragment with a specific viral target protein.

Exposure of a cryptic Hsp70 binding site determines the cytotoxicity of the ALS-associated SOD1-mutant A4V.

The accumulation of toxic protein aggregates is thought to play a key role in a range of degenerative pathologies, but it remains unclear why aggregation of polypeptides into non-native assemblies is toxic and why cellular clearance pathways offer ineffective protection. We here study the A4V mutant of SOD1, which forms toxic aggregates in motor neurons of patients with familial amyotrophic lateral sclerosis (ALS). A comparison of the location of aggregation prone regions (APRs) and Hsp70 binding sites in the denatured state of SOD1 reveals that ALS-associated mutations promote exposure of the APRs more than the strongest Hsc/Hsp70 binding site that we could detect.

High incidence of venous thromboembolic events in anticoagulated severe COVID-19 patients.

Background: Coagulopathy is a common abnormality in patients with COVID-19. However, the exact incidence of venous thromboembolic event is unknown in anticoagulated, severe COVID-19 patients.

Objectives: Systematic assessment of venous thromboembolism (VTE) using complete duplex ultrasound (CDU) in anticoagulated COVID-19 patients.

Autonomous aggregation suppression by acidic residues explains why chaperones favour basic residues.

Many chaperones favour binding to hydrophobic sequences that are flanked by basic residues while disfavouring acidic residues. However, the origin of this bias in protein quality control remains poorly understood. Here, we show that while acidic residues are the most efficient aggregation inhibitors, they are also less compatible with globular protein structure than basic amino acids.

The CAHP (cardiac arrest hospital prognosis) score: A tool for risk stratification after out-of-hospital cardiac arrest in elderly patients.

Background: Older age is associated with worse outcome after out-of-hospital cardiac arrest (OHCA). Therefore, we tested the performance of CAHP score, to predict neurological outcome in elderly OHCA patients and to select patients most likely to benefit from coronary angiogram (CAG).

Materials And Methods: The present study was a retrospective multicentre observational study at 3 non-university hospitals and 1 university hospital.

WALTZ-DB 2.0: an updated database containing structural information of experimentally determined amyloid-forming peptides.

Transition of soluble proteins into insoluble amyloid fibrils is driven by self-propagating short sequence stretches. However, accurate prediction of aggregation determinants remains challenging. Here, we describe WALTZ-DB 2.

Aggregating sequences that occur in many proteins constitute weak spots of bacterial proteostasis.

Aggregation is a sequence-specific process, nucleated by short aggregation-prone regions (APRs) that can be exploited to induce aggregation of proteins containing the same APR. Here, we find that most APRs are unique within a proteome, but that a small minority of APRs occur in many proteins. When aggregation is nucleated in bacteria by such frequently occurring APRs, it leads to massive and lethal inclusion body formation containing a large number of proteins.

Dry Reforming of Methane in a Gliding Arc Plasmatron: Towards a Better Understanding of the Plasma Chemistry.

Dry reforming of methane (DRM) in a gliding arc plasmatron is studied for different CH fractions in the mixture. The CO and CH conversions reach their highest values of approximately 18 and 10 %, respectively, at 25 % CH in the gas mixture, corresponding to an overall energy cost of 10 kJ L (or 2.5 eV per molecule) and an energy efficiency of 66 %.