The BRAF pseudogene functions as a competitive endogenous RNA and induces lymphoma in vivo.

Research over the past decade has suggested important roles for pseudogenes in physiology and disease. In vitro experiments demonstrated that pseudogenes contribute to cell transformation through several mechanisms. However, in vivo evidence for a causal role of pseudogenes in cancer development is lacking. Here, we report that mice engineered to overexpress either the full-length murine B-Raf pseudogene Braf-rs1 or its pseudo "CDS" or "3' UTR" develop an aggressive malignancy resembling human diffuse large B cell lymphoma. We show that Braf-rs1 and its human ortholog, BRAFP1, elicit their oncogenic activity, at least in part, as competitive endogenous RNAs (ceRNAs) that elevate BRAF expression and MAPK activation in vitro and in vivo. Notably, we find that transcriptional or genomic aberrations of BRAFP1 occur frequently in multiple human cancers, including B cell lymphomas. Our engineered mouse models demonstrate the oncogenic potential of pseudogenes and indicate that ceRNA-mediated microRNA sequestration may contribute to the development of cancer.

Hypoxia-Inducible Factor-1α in Macrophages, but Not in Neutrophils, Is Important for Host Defense during Klebsiella pneumoniae-Induced Pneumosepsis.

Hypoxia-inducible factor- (HIF-) 1α has been implicated in the ability of cells to adapt to alterations in oxygen levels. Bacterial stimuli can induce HIF1α in immune cells, including those of myeloid origin. We here determined the role of myeloid cell HIF1α in the host response during pneumonia and sepsis caused by the common human pathogen Klebsiella pneumoniae. To this end, we generated mice deficient for HIF1α in myeloid cells (LysM-cre × Hif1α fl/fl) or neutrophils (Mrp8-cre × Hif1α fl/fl) and infected these with Klebsiella pneumoniae via the airways. Myeloid, but not neutrophil, HIF1α-deficient mice had increased bacterial loads in the lungs and distant organs after infection as compared to control mice, pointing at a role for HIF1α in macrophages. Myeloid HIF1α-deficient mice did not show increased bacterial growth after intravenous infection, suggesting that their phenotype during pneumonia was mediated by lung macrophages. Alveolar and lung interstitial macrophages from LysM-cre × Hif1α fl/fl mice produced lower amounts of the immune enhancing cytokine tumor necrosis factor upon stimulation with Klebsiella, while their capacity to phagocytose or to produce reactive oxygen species was unaltered. Alveolar macrophages did not upregulate glycolysis in response to lipopolysaccharide, irrespective of HIF1α presence. These data suggest a role for HIF1α expressed in lung macrophages in protective innate immunity during pneumonia caused by a common bacterial pathogen.

Integrated transcriptional and competitive endogenous RNA networks are cross-regulated in permissive molecular environments.

Competitive endogenous (ce)RNAs cross-regulate each other through sequestration of shared microRNAs and form complex regulatory networks based on their microRNA signature. However, the molecular requirements for ceRNA cross-regulation and the extent of ceRNA networks remain unknown. Here, we present a mathematical mass-action model to determine the optimal conditions for ceRNA activity in silico. This model was validated using phosphatase and tensin homolog (PTEN) and its ceRNA VAMP (vesicle-associated membrane protein)-associated protein A (VAPA) as paradigmatic examples. A computational assessment of the complexity of ceRNA networks revealed that transcription factor and ceRNA networks are intimately intertwined. Notably, we found that ceRNA networks are responsive to transcription factor up-regulation or their aberrant expression in cancer. Thus, given optimal molecular conditions, alterations of one ceRNA can have striking effects on integrated ceRNA and transcriptional networks.

Impact of Rapid Up-Titration of Guideline-Directed Medical Therapies on Quality of Life: Insights From the STRONG-HF Trial.

BACKGROUND: This analysis provides details on baseline and changes in quality of life (QoL) and its components as measured by EQ-5D-5L questionnaire, as well as association with objective outcomes, applying high-intensity heart failure (HF) care in patients with acute HF. METHODS: In STRONG-HF trial (Safety, Tolerability, and Efficacy of Rapid Optimization, Helped by NT-proBNP Testing, of Heart Failure Therapies) patients with acute HF were randomized just before discharge to either usual care or a high-intensity care strategy of guideline-directed medical therapy up-titration. Patients ranked their state of health on the EQ-5D visual analog scale score ranging from 0 (the worst imaginable health) to 100 (the best imaginable health) at baseline and at 90 days follow-up. RESULTS: In 1072 patients with acute HF with available assessment of QoL (539/533 patients assigned high-intensity care/usual care) the mean baseline EQ-visual analog scale score was 59.2 (SD, 15.1) with no difference between the treatment groups. Patients with lower baseline EQ-visual analog scale (meaning worse QoL) were more likely to be women, self-reported Black and non-European (P<0.001). The strongest independent predictors of a greater improvement in QoL were younger age (P<0.001), no HF hospitalization in the previous year (P<0.001), lower NYHA class before hospital admission (P<0.001) and high-intensity care treatment (mean difference, 4.2 [95% CI, 2.5-5.8]; P<0.001). No statistically significant heterogeneity in the benefits of high-intensity care was seen across patient subgroups of different ages, with left ventricular ejection fraction above or below 40%, NT-proBNP (N-terminal pro-B-type natriuretic peptide) and systolic blood pressure above or below the median value. The treatment effect on the primary end point did not vary significantly across baseline EQ-visual analog scale (Pinteraction=0.87). CONCLUSIONS: Early up-titration of guideline-directed medical therapy significantly improves all dimensions of QoL in patients with HF and improves prognosis regardless of baseline self-assessed health status. The likelihood of achieving optimal doses of HF medications does not depend on baseline QoL. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03412201.

Lymphopenia is associated with broad host response aberrations in community-acquired pneumonia.

OBJECTIVES: Lymphopenia at hospital admission occurs in over one-third of patients with community-acquired pneumonia (CAP), yet its clinical relevance and pathophysiological implications remain underexplored. We evaluated outcomes and immune features of patients with lymphopenic CAP (L-CAP), a previously described immunophenotype characterized by admission lymphocyte count <0.724 × 109 cells/L. METHODS: Observational study in 149 patients admitted to a general ward for CAP. We measured 34 plasma biomarkers reflective of inflammation, endothelial cell responses, coagulation, and immune checkpoints. We characterized lymphocyte phenotypes in 29 patients using spectral flow cytometry. RESULTS: L-CAP occurred in 45 patients (30.2%) and was associated with prolonged time-to-clinical-stability (median 5 versus 3 days), also when we accounted for competing events for reaching clinical stability and adjusted for baseline covariates (subdistribution hazard ratio 0.63; 95% confidence interval 0.45-0.88). L-CAP patients demonstrated a proportional depletion of CD4 T follicular helper cells, CD4 T effector memory cells, naïve CD8 T cells and IgG+ B cells. Plasma biomarker analyses indicated increased activation of the cytokine network and the vascular endothelium in L-CAP. CONCLUSIONS: L-CAP patients have a protracted clinical recovery course and a more broadly dysregulated host response. These findings highlight the prognostic and pathophysiological relevance of admission lymphopenia in patients with CAP.

Insights on prevalence and incidence of anemia and rapid up-titration of oral heart failure treatment from the STRONG-HF study.

BACKGROUND: Anemia is one of the most frequent comorbidities in patients with heart failure (HF), which potentially can interfere with the effect of guideline-recommended HF medical therapy and can be associated with the use of neurohormonal blockers. AIM: The aim of this analysis was to determine the prevalence and changes of anemia status in the STRONG-HF study, its association with clinical endpoints, and possible interaction of the presence of anemia with the efficacy and safety of high-intensity HF treatment. METHODS: The design and main results of the study have been previously described. Patients were randomized within 2 days prior to anticipated hospital discharge after HF worsening in a 1:1 fashion to either high-intensity care (HIC) or usual care (UC). Baseline characteristics, clinical and safety outcomes, and treatment effect of HIC vs. UC on the primary and secondary outcomes were compared in groups based on baseline anemia. In addition, dynamics of hemoglobin during the study follow-up and predictors of incident anemia at 90 days were investigated. RESULTS: The proportion of anemia in 1077 STRONG-HF patients at enrollment was 27.2%, while at 90 days, it changed to 32.1%. The primary composite outcome occurred in 18.2% of patients without baseline anemia, and 22.5% of patients with baseline anemia (unadjusted HR 1.27; 95% CI 0.90-1.80), a difference that did not reach statistical significance. However, patients with baseline anemia had significantly less improvement of EQ-VAS questionnaire values from baseline to day 90 (adjusted LS-Mean difference -2.34 (-4.37, -0.31), P = 0.02). During the study, anemia developed in 19.4 and 14.6% in HIC and UC groups, respectively. The opposite phenomenon-recovery of anemia-occurred in 27.6 and 28.8% in HIC and UC groups (P = 0.1379). The predictors of incident anemia at 90 days were male sex, geographical region other than Europe, ischemic etiology, higher glucose, and elevated uric acid at baseline. The percentages of optimal doses of renin-angiotensin system inhibitors, beta-blockers, and mineralocorticoid receptor antagonists were not different between anemic and non-anemic patients. High-intensity care strategy did not increase rate of incident anemia at 90 days and reduced the rate of primary and secondary endpoints regardless of baseline hemoglobin. CONCLUSION: Hemoglobin level and status of anemia have a dynamic nature in the acute HF patients in the post-discharge period dependent on multiple factors. High-intensity HF treatment is safe and beneficial regardless of baseline hemoglobin level and presence of anemia. The improvement of quality of life is significantly lower in anemic HF patients implying specific attention to correction of this condition.

Platelets interact with CD169+ macrophages and cDC1 and enhance liposome-induced CD8+ T cell responses.

Historically platelets are mostly known for their crucial contribution to hemostasis, but there is growing understanding of their role in inflammation and immunity. The immunomodulatory role of platelets entails interaction with pathogens, but also with immune cells including macrophages and dendritic cells (DCs), to activate adaptive immune responses. In our previous work, we have demonstrated that splenic CD169+ macrophages scavenge liposomes and collaborate with conventional type 1 DCs (cDC1) to induce expansion of CD8+ T cells. Here, we show that platelets associate with liposomes and bind to DNGR-1/Clec9a and CD169/Siglec-1 receptors in vitro. In addition, platelets interacted with splenic CD169+ macrophages and cDC1 and further increased liposome internalization by cDC1. Most importantly, platelet depletion prior to liposomal immunization resulted in significantly diminished antigen-specific CD8+ T cell responses, but not germinal center B cell responses. Previously, complement C3 was shown to be essential for platelet-mediated CD8+ T cell activation during bacterial infection. However, after liposomal vaccination CD8+ T cell priming was not dependent on complement C3. While DCs from platelet-deficient mice exhibited unaltered maturation status, they did express lower levels of CCR7. In addition, in the absence of platelets, CCL5 plasma levels were significantly reduced. Overall, our findings demonstrate that platelets engage in a cross-talk with CD169+ macrophages and cDC1 and emphasize the importance of platelets in induction of CD8+ T cell responses in the context of liposomal vaccination.

Platelets of COVID-19 patients display mitochondrial dysfunction, oxidative stress, and energy metabolism failure compatible with cell death.

Background: Alterations in platelet function have been implicated in the pathophysiology of COVID-19 since the beginning of the pandemic. While early reports linked hyperactivated platelets to thromboembolic events in COVID-19, subsequent investigations demonstrated hyporeactive platelets with a procoagulant phenotype. Mitochondria are important for energy metabolism and the function of platelets. Objectives: Here, we sought to map the energy metabolism of platelets in a cohort of noncritically ill COVID-19 patients and assess platelet mitochondrial function, activation status, and responsiveness to external stimuli. Methods: We enrolled hospitalized COVID-19 patients and controls between October 2020 and December 2021. Platelets function and metabolism was analyzed by flow cytometry, metabolomics, glucose fluxomics, electron and fluorescence microscopy and western blot. Results: Platelets from COVID-19 patients showed increased phosphatidylserine externalization indicating a procoagulant phenotype and hyporeactivity to ex vivo stimuli, associated with profound mitochondrial dysfunction characterized by mitochondrial depolarization, lower mitochondrial DNA-encoded transcript levels, an altered mitochondrial morphology consistent with increased mitochondrial fission, and increased pyruvate/lactate ratios in platelet supernatants. Metabolic profiling by untargeted metabolomics revealed NADH, NAD+, and ATP among the top decreased metabolites in patients' platelets, suggestive of energy metabolism failure. Consistently, platelet fluxomics analyses showed a strongly reduced utilization of 13C-glucose in all major energy pathways together with a rerouting of glucose to de novo generation of purine metabolites. Patients' platelets further showed evidence of oxidative stress, together with increased glutathione oxidation and synthesis. Addition of plasma from COVID-19 patients to normal platelets partially reproduced the phenotype of patients' platelets and disclosed a temporal relationship between mitochondrial decay and (subsequent) phosphatidylserine exposure and hyporeactivity. Conclusion: These data link energy metabolism failure in platelets from COVID-19 patients with a prothrombotic platelet phenotype with features matching cell death.

Early changes in renal function during rapid up-titration of guideline-directed medical therapy following an admission for acute heart failure.

AIM: In this subgroup analysis of STRONG-HF, we explored the association between changes in renal function and efficacy of rapid up-titration of guideline-directed medical therapy (GDMT) according to a high-intensity care (HIC) strategy. METHODS AND RESULTS: In patients randomized to the HIC arm (n = 542), renal function was assessed at baseline and during follow-up visits. We studied the association with clinical characteristics and outcomes of a decrease in estimated glomerular filtration rate (eGFR) at week 1, defined as ≥15% decrease from baseline. Patients in the usual care group (n = 536) were seen at day 90. The treatment effect of HIC versus usual care was independent of baseline eGFR (p-interaction = 0.4809). A decrease in eGFR within 1 week occurred in 77 (15.5%) patients and was associated with more rales on examination (p = 0.004), and a higher New York Heart Association class at the corresponding visit. Following the decrease in eGFR at 1 week, lower average optimal doses of GDMT were prescribed during follow-up (p = 0.0210) and smaller reductions in N-terminal pro-B-type natriuretic peptide occurred (geometrical mean 0.81 in no eGFR decrease vs 1.12 in GFR decrease, p = 0.0003). The rate of heart failure (HF) readmission or death at 180 days was 12.3% in no eGFR decrease versus 18.5% in eGFR decrease (p = 0.2274) and HF readmissions were 7.8% versus 16.6% (p = 0.0496). CONCLUSIONS: In the STRONG-HF study, HIC reduced 180-day HF readmission or death regardless of baseline eGFR. An early decrease in eGFR during rapid up-titration of GDMT was associated with more evidence of congestion, yet lower doses of GDMT during follow-up.

Sex-specific analysis of the rapid up-titration of guideline-directed medical therapies after a hospitalization for acute heart failure: Insights from the STRONG-HF trial.

AIMS: The aim of this study was to evaluate efficacy and safety of rapid up-titration of guideline-directed medical therapies (GDMT) in men and women hospitalized for acute heart failure (AHF). METHODS AND RESULTS: In STRONG-HF, AHF patients were randomized just prior to discharge to either usual care (UC) or a high-intensity care (HIC) strategy of GDMT up-titration. In these analyses, we compared the implementation, efficacy, and safety of the HIC strategy between men and women. In the randomized AHF population, 416/1078 (39%) were women. By day 90, a higher proportion of both sexes in the HIC group had been up-titrated to full doses of GDMT compared to UC. Overall, there were no differences in the primary endpoint between the sexes. The primary endpoint, 180-day heart failure readmission or death, occurred in 15.8% HIC women versus 23.5% women in the UC group (adjusted hazard ratio [HR] 0.67, 95% confidence interval [CI] 0.40-1.13) and in 14.9% HIC men versus 23.5% UC men (adjusted HR 0.57, 95% CI 0.38-0.88) (adjusted interaction p = 0.65). There was no significant treatment-by-sex interaction in quality-of-life improvement or in adverse events, including serious or fatal adverse events. CONCLUSION: The results of the current analyses suggest that a rapid up-titration of GDMT immediately after an AHF hospitalization can and should be implemented similarly in men and women, as it results in reduction of 180-day all-cause death or heart failure readmission, quality-of-life improvement in both men and women with a similar safety profile.

The Platelet Lipidome Is Altered in Patients with COVID-19 and Correlates with Platelet Reactivity.

BACKGROUND: Activated platelets have been implicated in the proinflammatory and prothrombotic phenotype of coronavirus disease 2019 (COVID-19). While it is increasingly recognized that lipids have important structural and signaling roles in platelets, the lipidomic landscape of platelets during infection has remained unexplored. OBJECTIVE: To investigate the platelet lipidome of patients hospitalized for COVID-19. METHODS: We performed untargeted lipidomics in platelets of 25 patients hospitalized for COVID-19 and 23 noninfectious controls with similar age and sex characteristics, and with comparable comorbidities. RESULTS: Twenty-five percent of the 1,650 annotated lipids were significantly different between the groups. The significantly altered part of the platelet lipidome mostly comprised lipids that were less abundant in patients with COVID-19 (20.4% down, 4.6% up, 75% unchanged). Platelets from COVID-19 patients showed decreased levels of membrane plasmalogens, and a distinct decrease of long-chain, unsaturated triacylglycerols. Conversely, platelets from patients with COVID-19 displayed class-wide higher abundances of bis(monoacylglycero)phosphate and its biosynthetic precursor lysophosphatidylglycerol. Levels of these classes positively correlated with ex vivo platelet reactivity-as measured by P-selectin expression after PAR1 activation-irrespective of disease state. CONCLUSION: Taken together, this investigation provides the first exploration of the profound impact of infection on the human platelet lipidome, and reveals associations between the lipid composition of platelets and their reactivity. These results warrant further lipidomic research in other infections and disease states involving platelet pathophysiology.

The host response in different aetiologies of community-acquired pneumonia.

BACKGROUND: Community-acquired pneumonia (CAP) can be caused by a variety of pathogens, of which Streptococcus pneumoniae, Influenza and currently SARS-CoV-2 are the most common. We sought to identify shared and pathogen-specific host response features by directly comparing different aetiologies of CAP. METHODS: We measured 72 plasma biomarkers in a cohort of 265 patients hospitalized for CAP, all sampled within 48 hours of admission, and 28 age-and sex matched non-infectious controls. We stratified the biomarkers into several pathophysiological domains- antiviral response, vascular response and function, coagulation, systemic inflammation, and immune checkpoint markers. We directly compared CAP caused by SARS-CoV-2 (COVID-19, n=39), Streptococcus pneumoniae (CAP-strep, n=27), Influenza (CAP-flu, n=22) and other or unknown pathogens (CAP-other, n=177). We adjusted the comparisons for age, sex and disease severity scores. FINDINGS: Biomarkers reflective of a stronger cell-mediated antiviral response clearly separated COVID-19 from other CAPs (most notably granzyme B). Biomarkers reflecting activation and function of the vasculature showed endothelial barrier integrity was least affected in COVID-19, while glycocalyx degradation and angiogenesis were enhanced relative to other CAPs. Notably, markers of coagulation activation, including D-dimer, were not different between the CAP groups. Ferritin was most increased in COVID-19, while other systemic inflammation biomarkers such as IL-6 and procalcitonin were highest in CAP-strep. Immune checkpoint markers showed distinctive patterns in viral and non-viral CAP, with highly elevated levels of Galectin-9 in COVID-19. INTERPRETATION: Our investigation provides insight into shared and distinct pathophysiological mechanisms in different aetiologies of CAP, which may help guide new pathogen-specific therapeutic strategies. FUNDING: This study was financially supported by the Dutch Research Council, the European Commission and the Netherlands Organization for Health Research and Development.

Comparison of inhibitory effects of irreversible and reversible Btk inhibitors on platelet function.

All irreversible Bruton tyrosine kinase (Btk) inhibitors including ibrutinib and acalabrutinib induce platelet dysfunction and increased bleeding risk. New reversible Btk inhibitors were developed, like MK-1026. The mechanism underlying increased bleeding tendency with Btk inhibitors remains unclear. We investigated the effects of ibrutinib, acalabrutinib and MK-1026 on platelet function in healthy volunteers, patients and Btk-deficient mice, together with off-target effects on tyrosine kinase phosphorylation. All inhibitors suppressed GPVI- and CLEC-2-mediated platelet aggregation, activation and secretion in a dose-dependent manner. Only ibrutinib inhibited thrombus formation on vWF-co-coated surfaces, while on collagen this was not affected. In blood from Btk-deficient mice, collagen-induced thrombus formation under flow was reduced, but preincubation with either inhibitor was without additional effects. MK-1026 showed less off-target effects upon GPVI-induced TK phosphorylation as compared to ibrutinib and acalabrutinib. In ibrutinib-treated patients, GPVI-stimulated platelet activation, and adhesion on vWF-co-coated surfaces were inhibited, while CLEC-2 stimulation induced variable responses. The dual inhibition of GPVI and CLEC-2 signalling by Btk inhibitors might account for the increased bleeding tendency, with ibrutinib causing more high-grade bleedings due to additional inhibition of platelet-vWF interaction. As MK-1026 showed less off-target effects and only affected activation of isolated platelets, it might be promising for future treatment.

Epinephrine and short-term survival in cardiogenic shock: an individual data meta-analysis of 2583 patients.

OBJECTIVE: Catecholamines have been the mainstay of pharmacological treatment of cardiogenic shock (CS). Recently, use of epinephrine has been associated with detrimental outcomes. In the present study we aimed to evaluate the association between epinephrine use and short-term mortality in all-cause CS patients. DESIGN: We performed a meta-analysis of individual data with prespecified inclusion criteria: (1) patients in non-surgical CS treated with inotropes and/or vasopressors and (2) at least 15% of patients treated with epinephrine administrated alone or in association with other inotropes/vasopressors. The primary outcome was short-term mortality. MEASUREMENTS AND RESULTS: Fourteen published cohorts and two unpublished data sets were included. We studied 2583 patients. Across all cohorts of patients, the incidence of epinephrine use was 37% (17-76%) and short-term mortality rate was 49% (21-69%). A positive correlation was found between percentages of epinephrine use and short-term mortality in the CS cohort. The risk of death was higher in epinephrine-treated CS patients (OR [CI] = 3.3 [2.8-3.9]) compared to patients treated with other drug regimens. Adjusted mortality risk remained striking in epinephrine-treated patients (n = 1227) (adjusted OR = 4.7 [3.4-6.4]). After propensity score matching, two sets of 338 matched patients were identified and epinephrine use remained associated with a strong detrimental impact on short-term mortality (OR = 4.2 [3.0-6.0]). CONCLUSIONS: In this very large cohort, epinephrine use for hemodynamic management of CS patients is associated with a threefold increase of risk of death.

Correction to: Epinephrine and short-term survival in cardiogenic shock: an individual data meta-analysis of 2583 patients.

Because of a technical error, the code corresponding to the outcome for the Basir et al. cohort was mis-implemented in the original version of our article. Characteristics of the cohort are in fact the followings.

PTEN controls junction lengthening and stability during cell rearrangement in epithelial tissue.

Planar cell rearrangements control epithelial tissue morphogenesis and cellular pattern formation. They lead to the formation of new junctions whose length and stability determine the cellular pattern of tissues. Here, we show that during Drosophila wing development the loss of the tumor suppressor PTEN disrupts cell rearrangements by preventing the lengthening of newly formed junctions that become unstable and keep on rearranging. We demonstrate that the failure to lengthen and to stabilize is caused by the lack of a decrease of Myosin II and Rho-kinase concentration at the newly formed junctions. This defect results in a heterogeneous cortical contractility at cell junctions that disrupts regular hexagonal pattern formation. By identifying PTEN as a specific regulator of junction lengthening and stability, our results uncover how a homogenous distribution of cortical contractility along the cell cortex is restored during cell rearrangement to control the formation of epithelial cellular pattern.