Risultati per: Identificate le origini evolutive di SARS-CoV-2

Circulation, Volume 148, Issue Suppl_1, Page A12759-A12759, November 6, 2023. Introduction:Scattered studies suggest that SARS-CoV-2 spike protein (SP) promotes platelet activation, though the exact mechanism is unknown. Thymidine phosphorylase (TYMP), which facilitates platelet activation and thrombosis, is significantly increased in the plasma and lungs of COVID-19 patients, suggesting that TYMP may play a role in the COVID-19 milieu.Hypothesis:We hypothesize that TYMP enhances SP/platelet factor 4 (PF4) complex formation and inhibition of TYMP attenuates SP-induced thrombosis and/or inflammation.Methods:BEAS-2B cells were treated with SP- or its receptor binding domain (RBD)-containing COS-7 cell lysate, or control cell lysate (p3.1) and TYMP and STAT3 expression were determined by western blot. The effect of SP on thrombosis was examined in K18-hACE2 and K18-hACE2/Tymp-/-mice using the ferric chloride-induced carotid artery injury thrombosis model. SP-, TYMP-, or PF4-encoding plasmids were co-transfected into COS-7 and their protein interactions were assessed using co-IP, Blue Native-PAGE, and immunocytochemistry.Results:SP increased expression of TYMP and pY705-STAT3 in BEAS-2B. siRNA-mediated knockdown of TYMP reduced STAT3 activation. SP significantly enhanced thrombosis in the K18-hACE2 mice, which was inhibited by simultaneously treating mice with tipiracil, a selective TYMP inhibitor (Figure). K18-hACE2/Tymp-/-mice were resistant to SP-enhanced thrombosis. For the first time, we found that SP, PF4, and TYMP form a complex whose formation is dose-dependently enhanced by TYMP.Conclusions:Our studies suggest that SARS-CoV-2 SP enhances TYMP expression and is prothrombotic and proinflammatory. TYMP inhibition, either via genetic knockout or by its chemical inhibitor, attenuates SP-enhanced thrombosis. TYMP promotes the formation of a PF4/SP complex, which provides a novel insight into COVID-19-associated thrombosis. TYMP could be a novel therapeutic target for COVID-19-associated sequelae.

Circulation, Volume 148, Issue Suppl_1, Page A15709-A15709, November 6, 2023. Background:SARS-CoV-2 (COVID-19) transmits a multi-systemic disease that can lead to acute respiratory distress syndrome. Growth hormone-releasing hormone receptor (GHRH-R) and its splice variant are expressed in murine and human lung and heart. GHRH-R antagonist, MIA-602, has been shown to regulate inflammation in animal models and immune cell responses to bleomycin lung injury. Using a BSL2-compatible recombinant VSV-eGFP-SARS-CoV-2-S virus (rVSV-SARS-CoV-2-S) which mimics native SARS-CoV-2 infection in K18 hACE2tg mice, we tested our hypothesis that MIA-602 attenuates COVID-19-induced cardiopulmonary injury by reducing inflammation.Methods:Male and female K18-hACE2tg mice were infected with SARS-CoV-2/USA-WA1/2020, rVSV-SARS-CoV-2-S, or PBS and lung viral load, weight-loss and histopathology were compared (N=8). Mice infected with rVSV-SARS-CoV-2-S were subject to daily subcutaneous injections of 10 μg MIA-602 or vehicle (control) starting at 24h post-infection. Pulmonary function was measured via whole-body plethysmography on day 0, day 3, and day 5 (n=7). Five days after viral infection mice were sacrificed, and blood and tissues collected for histopathological analyses, H&E staining, RNA and protein work. Heart and lung tissues were used for RNASeq (n=3 per group). T-test or One-way ANOVA-test was used for statistical analysis.Results:SARS-CoV-2 and rVSV-SARS-CoV-2-S presented similar pathology for weight loss, infectivity (~60%) and histopathologic changes. Daily treatment with MIA-602 ameliorated weight loss, reduced lung inflammation, pneumonia and pulmonary dysfunction evidenced by rescued respiratory rate, expiratory parameters, and dysregulated airway parameters (p

Circulation, Volume 148, Issue Suppl_1, Page A15405-A15405, November 6, 2023. Introduction:Post-acute sequelae of SARS-CoV-2 infection consist of pulmonary and extrapulmonary conditions, including a higher incidence of type 2 diabetes, but it remains unknown whether other cardiometabolic pathways are impacted by infection.Research Question:Does SARS-CoV-2 infection predict worsening cardiometabolic risk factors?Methods:Using data from OneFlorida+ (a PCORnet CRN), we compared changes over time in body mass index (BMI), systolic blood pressure (SBP) and low-density lipoprotein (LDL). We compared an Exposed cohort with a positive SARS-CoV-2 test or COVID-19 diagnosis code between March 2020 – January 2022 (n = 75,217; age: 48.5 y, 64% female), relative to a contemporary Unexposed cohort of adult patients with negative SARS-CoV-2 tests (n = 240,575; age: 52.7 y, 61% female), and an age/sex-matched Historical control cohort (March 2018 – January 2020; n = 75,217; age: 48.5 y, 64% female). We used multiple imputation for missingness in demographic and clinical factors and inverse probability weighting for confounding and loss to follow-up. We used doubly robust marginal structural models to estimate baseline and longitudinal differences in cardiometabolic indicators by cohort.Results:At the start of the follow-up period, adjusted for covariates and relative to the Exposed, the Unexposed (BMI: -0.5 [-0.6,-0.4] kg/m2, SBP: -0.5 [-0.8,-0.2] mmHg, LDL: -7.7 [-14.5, -1.0] mg/dL) and Historical control (BMI: -0.4 [-0.5,-0.3] kg/m2, SBP: -1.0 [-1.5,-0.6] mmHg, LDL: 12.5 [-58.3, 83.3] mg/dL) cohorts had better cardiometabolic profiles (Figure). Relative to changes in the Exposed, control cohorts displayed faster decreases in BMI (Unexposed only), slower increases in SBP, and no changes in LDL during the follow-up period.Conclusions:SARS-CoV-2 infection was associated with weight retention and a rise in blood pressure. Longer follow-up can help identify stability and impacts of these cardio-metabolic indices on events and mortality.

Circulation, Volume 148, Issue Suppl_1, Page A17307-A17307, November 6, 2023. Introduction:It is well known that SARS-Co-V2 infection can induce ER stress-associated activation of unfolded protein response (UPR) in various host cells which may contribute to the pathogenesis of COVID-19. However, the interplay between SARS-Co-V2 infection and UPR signaling in pre-existing ER stress associated pathological conditions has not been well elucidated.Hypothesis:We hypothesizedthat modulation of a pre-existing ER stress in host cells could attenuate susceptibility to SARS-CoV-2 infection by activating a range of cellular defense.Methods:Increasing concentrations of Tunicamycin (Tm) and Thapsigargin (Tg) have been used to induce ER stress in Huh-7 cells. After 6h treatment, cells were infected with SARS-CoV-2 pseudotyped particles (SARS-CoV-2pp) for 48 p.i. SARS-Co-V2-2pp entry was measured using Bright GloTMluciferase assay. Cell viability was measured by cell titer Glo®luminescent cell viability assay. The mRNA and protein expression of UPR markers were evaluated using RT-qPCR and Western blot methods.Results:Tm (5 μg/ml) and Tg (1 μM) efficiently inhibited SARS-CoV-2pp entry into cells without any cytotoxic effect. Chemical ER stress-induced inhibition of SARS-CoV-2pp entry was associated with significant reduction of ACE2 expression in Tg-infected cells but not with Tm. Strikingly, Tm and Tg revealed differential effects in modulating the expression of ER stress genes in infected cells. Both Tm and Tg significantly reduced the expression of stress-inducible ER chaperone GRP78/BIP in infected cells. In contrast, the IRE1-XBP1s and PERK-eIF2α-ATF4-CHOP signaling pathways were downregulated in Tg-infected cells only. Additionally, insulin-mediated glucose uptake, phosphorylation of Ser307IRS-1 and downstream p-AKT were enhanced in Tg-infected cells without any change in ERK phosphorylation.Conclusions:These findings suggest that pre-existing ER stress could modulate a specific UPR response in infected cells capable of counteracting the stress-inducible elements signaling, thereby depriving SARS-Co-V2 of essential components for their entry and replication. Pharmacological manipulation of ER stress in host cells might provide new therapeutic strategies to alleviate SARS-CoV-2 infection.

Circulation, Volume 148, Issue Suppl_1, Page A15524-A15524, November 6, 2023. Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The emergence of this virus has led to millions of deaths and the long-term cardiovascular and respiratory consequences of COVID-19 continue to pose a massive threat to public health. While recent studies have demonstrated that SARS-CoV-2 may enter kidney epithelial cells via angiotensin converting enzyme 2 (ACE2)-independent mechanisms by inducing receptor-independent macropinocytosis, it is currently unknown whether this process also occurs in cell types directly relevant to SARS-CoV-2-associated cardiovascular disease or pneumonia. Here, we investigated the ability of SARS-CoV-2 spike protein subunits to stimulate macropinocytosis in alveolar epithelial cells and macrophages. Flow cytometry analysis of fluid-phase marker internalization demonstrated that SARS-CoV-2 spike protein subunits S1, the receptor binding domain (RBD) of S1, and S2 stimulate macropinocytosis in both human and murine macrophages, but not in human lung epithelial cells. Pharmacological and genetic inhibition of macropinocytosis substantially decreased spike protein-induced macropinocytosis in macrophages bothin vitroandin vivo. High resolution scanning electron microscopy (SEM) imaging confirmed spike protein-induced plasma membrane activities characteristic of macropinocytosis. Mechanistic studies demonstrated that inhibition of protein kinase C and phosphoinositide 3-kinase in macrophages blocks SARS-CoV-2 spike protein-induced macropinocytosis. Further, pharmacological blockade of ACE2 did not inhibit macropinocytosis in SARS-CoV-2 spike protein-treated cells. To our knowledge, these results demonstrate for the first time that SARS-CoV-2 spike protein subunits stimulate macropinocytosis in macrophages. These results may contribute to a better understanding of SARS-CoV-2 infection and its cardiovascular and respiratory complications.

Circulation, Volume 148, Issue Suppl_1, Page A14877-A14877, November 6, 2023. The cellular entry of the SARS-CoV-2 virus depends on the binding of spike (S) protein to its biological ligand, ACE2. Although the virus commonly causes respiratory distress, cardiac injury can occur in COVID-19 patients, which is consistent with the expression of ACE2 in myocytes. Previous reports indicate SARS-CoV-2 proteins can target cardiac mitochondria and suppress mitochondrial function via enhancing MPTP pore opening and perturbing cardiac bioenergetics. To explore the underlying mechanism of the effect of SARS-CoV-2 on cardiac mitochondria, we measured the interactions of SARS-CoV-2 proteins with swine heart mitochondria in vitro. Incubation of recombinant S protein with isolated mitochondria significantly decreased state-3 oxygen consumption rate (OCR, 95.10 vs 65.68 nmol/min/mg) and FCCP uncoupling OCR (82.94 vs 66.95 nmol/min/mg). We further detected that S protein impaired the enzymatic activities of electron transport chain (ETC) (by 15.62% to 34.44%). However, S protein had no effect on TCA cycle enzymes, indicating the involvement of mitochondrial membrane components in decreased OCR by S proteins. Recombinant nucleocapsid (N) protein of SAR-CoV-2 had no effect on the OCR and ETC activities of swine mitochondria. S proteins decreased the intensity of mitochondrial heme spectrum determined by dithionite reduction with UV/VIS spectroscopy (by 17.52% hemea, 15.82% hemec1). The results were further assessed using isolated complex III (Cx3) and complex IV (Cx4). Treatment of isolated Cx3 and Cx4 with S protein decreased the spectral intensities of hemeaand hemec1. The spectra of both Cx3 and Cx4 were not affected by N protein. The results suggested S protein downregulates redox potentials of ETC in swine mitochondria. Treatment of swine mitochondria with S proteins enhanced superoxide (.O2–) generation by Cx1 (by 43.7%) and by Cx3 (by 10.9-fold) assessed by EPR and cytochromecreduction assays. However, we detected S proteins modestly decreased.O2–generation by swine mitochondria under state-2 condition (by 9.52%), indicating impairing pH gradient by S protein. In conclusion, the spike protein of SARS-CoV-2 virus mediates mitochondrial dysfunction of swine heart via impairing the redox function and increasing.O2–generation.

Circulation, Volume 148, Issue Suppl_1, Page A14911-A14911, November 6, 2023. Background:SARS-CoV-2 infection can result in cardiac complications, including myocarditis, left ventricular dysfunction, arrhythmias, and acute myocardial injury. Reports of effusive constrictive pericarditis (CP) are rare, and recommendations on management are limited.Description of Case:A 30-year-old male with recurrent episodes of effusive pericarditis after SARS-CoV-2 infection 11 months prior and anasarca presents with worsening fatigue, dyspnea, and weight gain. His echocardiogram showed pericardial thickening, annulus reversus, and interventricular septal bounce. Computed tomography showed pericardial thickening and a complex pericardial effusion. Right and left heart catheterization revealed elevated filling pressures, equalization of diastolic pressures, and ventricular discordance (Figure 1). Infection, malignancy, and autoimmune etiologies of CP were ruled out.Decision Making:The patient was initiated on anti-inflammatory therapy and aggressively diuresed with no improvement in his symptoms. Given recurrent episodes of pericarditis with constriction, the patient underwent a radical pericardiectomy with posterior pericardial release. The pericardium was 1 cm thick with severe fibrosis. Surgical pathology showed acute and chronic pericarditis with negative testing for Mycobacterium tuberculosis.Conclusion:Idiopathic, post-cardiac surgery and post-mediastinal radiation are the most common causes of CP. Acute pericarditis is a known complication of SARS-CoV-2 infection, but ongoing inflammation leading to CP is rare. CP presents with signs of heart failure and should be considered in patients with persistent symptoms of pericarditis.

New England Journal of Medicine, Volume 389, Issue 18, Page 1722-1724, November 2023.

Background
Predictors of COVID-19 vaccine immunogenicity and the influence of prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection require elucidation.

Methods
Stop the Spread Ottawa is a prospective cohort of individuals at-risk for or who have been infected with SARS-CoV-2, initially enrolled for 10 months beginning October 2020. This cohort was enriched for public-facing workers. This analysis focuses on safety and immunogenicity of the initial two doses of COVID-19 vaccine.

Results
Post-vaccination data with blood specimens were available for 930 participants. 22.8% were SARS-CoV2 infected prior to the first vaccine dose. Cohort characteristics include: median age 44 (IQR: 22–56), 66.6% women, 89.0% white, 83.2% employed. 38.1% reported two or more comorbidities and 30.8% reported immune compromising condition(s). Over 95% had detectable IgG levels against the spike and receptor binding domain (RBD) 3 months post second vaccine dose. By multivariable analysis, increasing age and high-level immune compromise predicted diminishing IgG spike and RBD titres at month 3 post second dose. IgG spike and RBD titres were higher immediately post vaccination in those with SARS-CoV-2 infection prior to first vaccination and spike titres were higher at 6 months in those with wider time intervals between dose 1 and 2. IgG spike and RBD titres and neutralisation were generally similar by sex, weight and whether receiving homogeneous or heterogeneous combinations of vaccines. Common symptoms post dose 1 vaccine included fatigue (64.7%), injection site pain (47.5%), headache (27.2%), fever/chills (26.2%) and body aches (25.3%). These symptoms were similar with subsequent doses.

Conclusion
The initial two COVID-19 vaccine doses are safe, well-tolerated and highly immunogenic across a broad spectrum of vaccine recipients including those working in public facing environments.

The antiviral drug molnupiravir was linked with a pattern of genomic changes in SARS-CoV-2, based on an analysis in Nature of more than 15 million global sequences.

To the Editor A recent study developed a data-driven scoring framework to classify postacute sequelae of SARS-CoV-2 infection (PASC). As stated in the accompanying Editorial, prior to developing a case definition, it is important to determine whether PASC is a single entity or multiple entities. Particularly, severe COVID-19 pneumonia requiring admission to the intensive care unit may lead to specific organ dysfunction and injury, including impaired cognitive function across multiple domains. Such dysfunction, consistent with the well-described post–intensive care syndrome, should be disentangled from PASC.

In Reply We agree with Dr Batra and colleagues that different manifestations of long COVID may arise due to different underlying pathological mechanisms of disease, which may be related to whether an individual was hospitalized during the acute phase of SARS-CoV-2 infection. However, we disagree that stratification by hospitalization status was needed to ensure the validity of the approach we used in our study.

Lavinia Valbonesi, moglie di Noboa, è nutrizionista e modella

Objectives
Infections by SARS-CoV-2 variants of concern (VOCs) might affect children and adolescents differently than earlier viral lineages. We aimed to address five questions about SARS-CoV-2 VOC infections in children and adolescents: (1) symptoms and severity, (2) risk factors for severe disease, (3) the risk of infection, (4) the risk of transmission and (5) long-term consequences following a VOC infection.

Design
Systematic review.

Data sources
The COVID-19 Open Access Project database was searched up to 1 March 2022 and PubMed was searched up to 9 May 2022.

Eligibility criteria
We included observational studies about Alpha, Beta, Gamma, Delta and Omicron VOCs among ≤18-year-olds. We included studies in English, German, French, Greek, Italian, Spanish and Turkish.

Data extraction and synthesis
Two reviewers extracted and verified the data and assessed the risk of bias. We descriptively synthesised the data and assessed the risks of bias at the outcome level.

Results
We included 53 articles. Most children with any VOC infection presented with mild disease, with more severe disease being described with the Delta or the Gamma VOC. Diabetes and obesity were reported as risk factors for severe disease during the whole pandemic period. The risk of becoming infected with a SARS-CoV-2 VOC seemed to increase with age, while in daycare settings the risk of onward transmission of VOCs was higher for younger than older children or partially vaccinated adults. Long-term symptoms following an infection with a VOC were described in

Introduction
People who are immunocompromised have a poor biological response to vaccinations. This study aims to determine in patients with chronic lymphocytic leukaemia (CLL) if a 3-week pause in Bruton tyrosine kinase inhibitor therapy (BTKi) starting 1 week before delivery of SARS-CoV-2 vaccine booster, improves vaccine immune response when compared with continuation of BTKi.

Methods and analysis
An open-label, randomised controlled superiority trial will be conducted in haematology clinics in approximately 10 UK National Health Service (NHS) hospitals. The sample size is 120, randomised 1:1 to intervention and usual care arms. The primary outcome is anti-spike-receptor binding domain (RBD) antibody level at 3 weeks post-SARS-CoV-2 booster vaccination. Secondary outcomes are RBD antibody levels at 12 weeks postbooster vaccination, participant global assessments of disease activity, blood films, full blood count and lactate dehydrogenase levels, impact on quality of life, self-reported adherence with request to temporarily pause or continue BTKi, T cell response against spike protein and relative neutralising antibody titre against SARS-CoV-2 viral variants. Additionally, there will be an investigation of any effects in those given influenza vaccination contemporaneously versus COVID-19 alone.
The primary analysis will be performed on the as randomised groups (‘intention to treat’). The difference between the study arms in anti-spike-RBD antibody level will be estimated using a mixed effects regression model, allowing for repeated measures clustered within participants. The model will be adjusted for randomisation factor (first line or subsequent line of therapy), and prior infection status obtained from prerandomisation antinucleocapsid antibodies as fixed effects.

Ethics and dissemination
This study has been approved by Leeds East Research Ethics Committee and Health Research Authority (REC Reference:22/YH/0226, IRAS ID: 319057). Dissemination will be via peer-review publications, newsletters and conferences. Results will be communicated to participants, the CLL patient and clinical communities and health policy-makers.

Trial registration number
ISRCTN14197181.

This longitudinal study of young children in 5 European countries investigates whether there is a temporal association between SARS-CoV-2 infection and islet autoimmunity when children are most susceptible.