Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Mécanismes de dégradation de l'ARN chez l'hôte et interaction du virus de l'influenza de type A : identification d'un rôle central de l'exonucléase ERI1 cellulaire dans le cycle de vie du virus de l'influenza de type A

Les mécanismes de dégradation de l'ARN représentent un processus cellulaire central. En effet, ils contrôlent la stabilité et la qualité de l'ARN et, par conséquent, régulent l'expression des gènes. D’une part, la régulation de la stabilité des transcrits est un élément essentiel au maintien de l’homéostasie cellulaire mais aussi à l’établissement d’une réponse cellulaire adaptée en cas d’infection virale. D’autre part, le succès de l’infection virale dépend fortement de la capacité du virus à prendre le contrôle des machineries d’expression géniques cellulaires. De ce fait, les virus doivent interagir avec les machineries cellulaires de dégradation de l’ARN afin de contrôler à la fois, l’expression des gènes cellulaires, et celle des gènes viraux. De nombreuses études rapportent l’existence d’une interface majeure d’interaction entre les machineries eucaryotes de dégradation de l’ARN et les protéines virales. Les virus ont non seulement la capacité d’échapper aux voies cellulaires de dégradation, mais ils peuvent également manipuler ces mécanismes cellulaires de dégradation de l’ARN afin de promouvoir leur propre réplication.Les virus influenza de type A (IAV) sont des agents pathogènes majeurs responsables d'épidémies annuelles et de pandémies occasionnelles. Pour leur cycle de réplication, les IAV dépendent de nombreuses protéines cellulaires et établissent ainsi un vaste et complexe réseau d’interactions avec le protéome cellulaire. Par ailleurs, plusieurs études rapportent l’existence de liens étroits entre les IAV et les machineries de dégradation de l’ARN. Ainsi, identifier les interactions mises en jeu lors du cycle viral participe à une meilleure compréhension du cycle viral, nécessaire au développement de stratégies antivirales. Nous avons recherché des interactions entre les protéines virales impliquées dans la réplication des IAV et un ensemble de 75 protéines cellulaires portant des activités exoribonucléases et/ou associées aux mécanismes de dégradation de l'ARN. Au total, 18 protéines ont été identifiées comme interagissant avec au moins une des protéines virales testées. Par ailleurs, l'analyse du réseau d'interaction a mis en évidence un ciblage spécifique et préférentiel des voies de dégradation de l'ARN par les protéines des IAV. Enfin, parmi les interacteurs validés, un criblage par ARN interférence a identifié neuf facteurs comme étant nécessaires à la multiplication virale.Nous avons choisi de nous concentrer sur l’exoribonucléase 1 (ERI1), identifiée comme interacteur de plusieurs composants des RNPv (RiboNucleoProtéine virale) (PB2, PB1 et NP). ERI1, via ses différents rôles dans l’homéostasie des petits ARN régulateurs, dans la maturation des ARN ribosomiques ou dans la maturation et la dégradation des ARNm histones possède un rôle central dans le contrôle de l’expression génique. En explorant l’interaction entre ERI1 et les protéines virales au cours de l’infection, nous avons mis en évidence que i) ERI1 favorise la transcription virale et que, pour ce faire, ses deux activités - liaison à l’ARN et exonucléase - sont nécessaires, ii) ERI1 interagit avec les protéines virales de manière dépendante de l’ARN, iii) ERI1 interagit avec les RNPv, iv) les protéines virales interagissent avec une forme d'ERI1 associée aux ARNm histones. Ainsi, nos données tendent vers un modèle dans lequel ERI1 associée aux ARNm histones est cooptée par la polymérase virale en transcription, favorisant ainsi la multiplication des IAV par un mécanisme qui reste cependant encore à déterminer. Ainsi, le ciblage de ERI1 par les IAV représente un autre exemple du détournement des machineries de dégradation de l’ARN par les virus, visant à créer un environnement cellulaire favorable à la réplication virale.RNA decay is a central cellular process as it regulates RNA stability and quality and thereby gene expression, which is essential to ensure proper cellular physiology and establishment of adapted responses to viral infection. Global takeover of gene expression machineries and rewiring of the cellular environment is key to the success of viral infection. Cellular proteome and viral replication are tightly connected and cellular RNA processing, stability, quality and decay accordingly influence the fate of the viral cycle. Growing evidence points towards the existence of a large interplay between eukaryotic RNA turnover machineries and viral proteins. Viruses not only evolved mechanisms to evade those RNA degradation pathways, but they also manipulate them to promote viral replication.Influenza A viruses (IAV) are major pathogens responsible for yearly epidemics and occasional pandemics. To complete their viral cycle, IAVs rely on many cellular proteins and establish a complex and highly coordinated interplay with the host proteome. Growing evidence supports the existence of a complex interplay between IAV viral proteins and RNA decay machineries. Unraveling such interplay is therefore essential to gain a better understanding of the IAV life cycle, required for the development of antiviral strategies. This led us to systematically screen interactions between viral proteins involved in IAV replication and a selected set of 75 cellular proteins carrying exoribonucleases activities or associated with RNA decay machineries. A total of 18 proteins were identified as interactors of at least one viral protein tested. Analysis of the interaction network highlighted a specific and preferential targeting of RNA degradation pathways by IAV proteins. Among validated interactors, a targeted RNAi screen identified nine factors as required for viral multiplication. We chose to focus on the 3’-5’ exoribonuclease 1 (ERI1), found in our screen as an interactor of several components of the vRNPs (viral RiboNucleoProtein) (PB2, PB1 and NP). The ERI1 protein is a major player in the control of cellular gene expression as it is essential for the maturation and decay of histone mRNA, maturation of 5.8S rRNA and miRNA homeostasis in mammalian cells. Exploring the interplay between ERI1 and viral proteins during the course of IAV infection we found that i) ERI1 promotes viral transcription, and both of its activities – RNA binding and exonuclease – are required, ii) ERI1 interacts with viral proteins in an RNA dependent manner, iii) ERI1 interacts with the transcribing vRNPs, iv) viral proteins interact with a form of ERI1 that is associated to histone mRNA. Ultimately, our data point to a model where ERI1 associated to histone mRNA is co-opted by the transcribing viral polymerase, thereby promoting IAV multiplication, through a mechanism that remains to be precisely determined. Targeting of ERI1 by IAV is another example further supporting the intricate interplay between IAV and RNA decay machineries, used to rewire cellular gene expression in order to create a favorable environment for viral replication

Nonproteolytic K29-Linked Ubiquitination of the PB2 Replication Protein of Influenza A Viruses by Proviral Cullin 4-Based E3 Ligases

International audienceThe multifunctional nature of viral proteins is essentially driven by posttranslational modifications (PTMs) and is key for the successful outcome of infection. For influenza A viruses (IAVs), a composite pattern of PTMs regulates the activity of viral proteins. However, almost none are known that target the PB2 replication protein, except for inducing its degradation. We show here that PB2 undergoes a nonproteolytic ubiquitination during infection. We identified E3 ubiquitin ligases catalyzing this ubiquitination as two multicomponent RING-E3 ligases based on cullin 4 (CRL4s), which are both contributing to the levels of ubiquitinated forms of PB2 in infected cells. The CRL4 E3 ligase activity is required for the normal progression of the viral cycle and for maximal virion production, indicating that the CRL4s mediate a ubiquitin signaling that promotes infection. The CRL4s are recruiting PB2 through an unconventional bimodal interaction with both the DDB1 adaptor and DCAF substrate receptors. While able to bind to PB2 when engaged in the viral polymerase complex, the CRL4 factors do not alter transcription and replication of the viral segments during infection. CRL4 ligases catalyze different patterns of lysine ubiquitination on PB2. Recombinant viruses mutated in the targeted lysines showed attenuated viral production, suggesting that CRL4-mediated ubiquitination of PB2 contributes to IAV infection. We identified K29-linked ubiquitin chains as main components of the nonproteolytic PB2 ubiquitination mediated by the CRL4s, providing the first example of the role of this atypical ubiquitin linkage in the regulation of a viral infection.IMPORTANCE Successful infection by influenza A virus, a pathogen of major public health importance, involves fine regulation of the multiple functions of the viral proteins, which often relies on post-translational modifications (PTMs). The PB2 protein of influenza A viruses is essential for viral replication and a key determinant of host range. While PTMs of PB2 inducing its degradation have been identified, here we show that PB2 undergoes a regulating PTM signaling detected during infection, based on an atypical K29-linked ubiquitination and mediated by two multicomponent E3 ubiquitin ligases. Recombinant viruses impaired for CRL4-mediated ubiquitination are attenuated, indicating that ubiquitination of PB2 is necessary for an optimal influenza A virus infection. The CRL4 E3 ligases are required for normal viral cycle progression and for maximal virion production. Consequently, they represent potential candidate host factors for antiviral targets

Emergencies and somatization.

The article presents the clinical profile of 72 patients with somatization seen by a psychiatric team at the request of somaticians in a emergency service in St Luc hospital (Brussels-Belgium). These include 37.5% of mood disorders, 11% of psychotic disorders and 20% of serious anxiety disorders. The psychiatric antecedents of these patients are very poor. Only the combined intervention of the somatician and the psychiatrist can improve the compliance and the level of psychiatric care which is very low

Influenza A virus co-opts ERI1 exonuclease bound to histone mRNA to promote viral transcription

International audienceCellular exonucleases involved in the processes that regulate RNA stability and quality control have been shown to restrict or to promote the multiplication cycle of numerous RNA viruses. Influenza A viruses are major human pathogens that are responsible for seasonal epidemics, but the interplay between viral proteins and cellular exonucleases has never been specifically studied. Here, using a stringent interactomics screening strategy and an siRNA-silencing approach, we identified eight cellular factors among a set of 75 cellular proteins carrying exo(ribo)nuclease activities or involved in RNA decay processes that support influenza A virus multiplication. We show that the exoribonuclease ERI1 interacts with the PB2, PB1 and NP components of the viral ribonucleoproteins and is required for viral mRNA transcription. More specifically, we demonstrate that the protein-protein interaction is RNA dependent and that both the RNA binding and exonuclease activities of ERI1 are required to promote influenza A virus transcription. Finally, we provide evidence that during infection, the SLBP protein and histone mRNAs co-purify with vRNPs alongside ERI1, indicating that ERI1 is most probably recruited when it is present in the histone pre-mRNA processing complex in the nucleus

SKAP2 Modular Organization Differently Recognizes SRC Kinases Depending on Their Activation Status and Localization

A preprint version has been deposited to Research Square at https://doi.org/10.21203/rs.3.rs-1430558/v1International audienceDimerization of SRC kinase adaptor phosphoprotein 2 (SKAP2) induces an increase of binding for most SRC kinases suggesting a fine-tuning with transphosphorylation for kinase activation. This work addresses the molecular basis of SKAP2-mediated SRC kinase regulation through the lens of their interaction capacities. By combining a luciferase complementation assay and extensive site-directed mutagenesis, we demonstrated that SKAP2 interacts with SRC kinases through a modular organization depending both on their phosphorylation-dependent activation and subcellular localization. SKAP2 contains three interacting modules consisting in the dimerization domain, the SRC homology 3 (SH3) domain, and the second interdomain located between the Pleckstrin homology and the SH3 domains. Functionally, the dimerization domain is necessary and sufficient to bind to most activated and myristyl SRC kinases. In contrast, the three modules are necessary to bind SRC kinases at their steady state. The Pleckstrin homology and SH3 domains of SKAP2 as well as tyrosines located in the interdomains modulate these interactions. Analysis of mutants of the SRC kinase family member hematopoietic cell kinase supports this model and shows the role of two residues, Y390 and K7, on its degradation following activation. In this article, we show that a modular architecture of SKAP2 drives its interaction with SRC kinases, with the binding capacity of each module depending on both their localization and phosphorylation state activation. This work opens new perspectives on the molecular mechanisms of SRC kinases activation, which could have significant therapeutic impact

Severe serotonin syndrome caused by an interaction between an antidepressant and a cough syrup

International audienc