The circadian clock remains intact, but with dampened hormonal output in heart failure.

Background: Circadian (24-h) rhythms are important regulators in physiology and disease, but systemic disease may disrupt circadian rhythmicity. Heart failure (HF) is a systemic disease affecting hormonal regulation. We investigate whether HF affects the rhythmic expression of melatonin and cortisol, main endocrine products of the central clock, and cardiac-specific troponin in patients.

Combinatorial analysis reveals highly coordinated early-stage immune reactions that predict later antiviral immunity in mild COVID-19 patients.

While immunopathology has been widely studied in patients with severe COVID-19, immune responses in non-hospitalized patients have remained largely elusive. We systematically analyze 484 peripheral cellular or soluble immune features in a longitudinal cohort of 63 mild and 15 hospitalized patients versus 14 asymptomatic and 26 household controls. We observe a transient increase of IP10/CXCL10 and interferon-β levels, coordinated responses of dominant SARS-CoV-2-specific CD4 and fewer CD8 T cells, and various antigen-presenting and antibody-secreting cells in mild patients within 3 days of PCR diagnosis.

N-Methyladenine in Eukaryotic DNA: Tissue Distribution, Early Embryo Development, and Neuronal Toxicity.

DNA methylation is one of the most important epigenetic modifications and is closely related with several biological processes such as regulation of gene transcription and the development of non-malignant diseases. The prevailing dogma states that DNA methylation in eukaryotes occurs essentially through 5-methylcytosine (5mC) but recently adenine methylation was also found to be present in eukaryotes. In mouse embryonic stem cells, 6-methyladenine (6mA) was associated with the repression and silencing of genes, particularly in the X-chromosome, known to play an important role in cell fate determination.

Protocol for a prospective, longitudinal cohort of people with COVID-19 and their household members to study factors associated with disease severity: the Predi-COVID study.

Introduction: A few major clinical factors such as sex, obesity or comorbidities have already been associated with COVID-19 severity, but there is a need to identify new epidemiological, clinical, digital and biological characteristics associated with severity and perform deep phenotyping of patients according to severity. The objectives of the Predi-COVID study are (1) to identify new determinants of COVID-19 severity and (2) to conduct deep phenotyping of patients by stratifying them according to risk of complications, as well as risk factors for infection among household members of Predi-COVID participants (the Predi-COVID-H ancillary study).

Methods And Analysis: Predi-COVID is a prospective, hybrid cohort study composed of laboratory-confirmed COVID-19 cases in Luxembourg who will be followed up remotely for 1 year to monitor their health status and symptoms.

The Long Noncoding RNA Landscape of Cardiac Regeneration in Zebrafish.

Background: Novel therapeutic targets of heart failure (HF) are needed. Long noncoding RNAs (lncRNAs) are engaged during cardiac regeneration. Unlike in humans, zebrafish naturally undergo cardiac regeneration after HF.

Atrial Structural Remodeling Gene Variants in Patients with Atrial Fibrillation.

Atrial fibrillation (AF) is a common arrhythmia for which the genetic studies mainly focused on the genes involved in electrical remodeling, rather than left atrial muscle remodeling. To identify rare variants involved in atrial myopathy using mutational screening, a high-throughput next-generation sequencing (NGS) workflow was developed based on a custom AmpliSeq™ panel of 55 genes potentially involved in atrial myopathy. This workflow was applied to a cohort of 94 patients with AF, 76 with atrial dilatation and 18 without.

Restoration of cardiac function after anaemia-induced heart failure in zebrafish.

Aims: New therapeutic approaches are needed to fight against the growing epidemic of heart failure. Unlike mammals, zebrafish possess the incredible ability to regenerate cardiac tissue after acute trauma such as apical resection. Yet, the ability of zebrafish to recover after a chronic stress leading to heart failure has not been reported.

Hypoxia inhibits lymphatic thoracic duct formation in zebrafish.

Hypoxia promotes blood vessel growth through up-regulation of pro-angiogenic pathways but its role on the lymphatic system remains unclear. The homeobox transcription factor Prox1 is a master control gene for generating lymphatic endothelial cells (LECs) and is up-regulated by hypoxia-inducible factors in mammals. While vascular endothelial growth factor A (VEGFA) is critical for angiogenesis, VEGFC and its receptor VEGF receptor-3 (VEGFR-3) are essential for the initial sprouting and directed migration as well as for the subsequent survival of LECs.

Use of Coronary Ultrasound Imaging to Evaluate Ventricular Function in Adult Zebrafish.

So far, imaging of the adult zebrafish heart and assessment of heart failure in adult zebrafish have been very limited. Here, we describe a new method for in vivo imaging of the hypertrabeculated heart of the adult zebrafish using miniaturized cardiac ultrasound catheters obtained from the cardiac catheterization laboratory. This method allows the observation of the ventricle of zebrafish and the assessment of ventricular diameters during diastole and systole, as well as heart rate and fractional shortening.

Adenosine stimulates angiogenesis by up-regulating production of thrombospondin-1 by macrophages.

Increase of blood capillary density at the interface between normal and ischemic tissue after acute MI reduces infarct size and improves cardiac function. Cardiac injury triggers the production of the matricellular component TSP-1, but its role in angiogenesis is not clear, as both anti- and proangiogenic properties have been reported. It is unknown whether TSP-1 is modulated by other factors released during cardiac injury.

Adenosine reduces cell surface expression of toll-like receptor 4 and inflammation in response to lipopolysaccharide and matrix products.

Recent evidence suggests that Toll-like receptor 4 (TLR4) is not only involved in innate immunity but is also an important mediator of adverse left ventricular remodeling and heart failure following acute myocardial infarction (MI). TLR4 is activated by lipopolysaccharide (LPS) but also by products of matrix degradation such as hyaluronic acid and heparan sulfate. Although cardioprotective properties of adenosine (Ado) have been extensively studied, its potential to interfere with TLR4 activation is unknown.

Adenosine modifies the balance between membrane and soluble forms of Flt-1.

VEGFR-1 (or Flt-1) exists under a sFlt-1 or a mFlt-1 form. sFlt-1 is antiangiogenic, and mFlt-1 is proangiogenic. The cardioprotective nucleoside Ado is proangiogenic, but its effects on Flt-1 are unknown and were tested in this study.

Adenosine up-regulates vascular endothelial growth factor in human macrophages.

It is known from animal models that the cardioprotective nucleoside adenosine stimulates angiogenesis mainly through up-regulation of vascular endothelial growth factor (VEGF). Since macrophages infiltrate the heart after infarction and because adenosine receptors behave differently across species, we evaluated the effect of adenosine on VEGF in human macrophages. Adenosine dose-dependently up-regulated VEGF expression and secretion by macrophages from healthy volunteers.

Activation of the adenosine-A3 receptor stimulates matrix metalloproteinase-9 secretion by macrophages.

Aims: Matrix metalloproteinase-9 (MMP-9) plays an important role in ventricular remodelling after acute myocardial infarction (MI). The cardioprotectant adenosine (Ado) may be involved in ventricular remodelling. We have shown that Ado inhibits the secretion of MMP-9 by human neutrophils.

Adenosine inhibits matrix metalloproteinase-9 secretion by neutrophils: implication of A2a receptor and cAMP/PKA/Ca2+ pathway.

Matrix metalloproteinases (MMPs), and in particular MMP-9 secreted by neutrophils, are capable of degrading the matrix components of the heart and are thought to be the driving force behind myocardial matrix remodeling after infarction. Adenosine, a naturally produced nucleoside, has been shown to have cardioprotective effects and to inhibit secretion of various cytokines. The aim of our study was to determine the effect of adenosine on the secretion of MMP-9 by neutrophils.

Matrix metalloproteinase-9 is a marker of heart failure after acute myocardial infarction.

Background: Matrix metalloproteinases (MMPs) have been associated with the development of left ventricular remodeling after myocardial infarction (MI). We sought to determine whether peripheral levels of MMPs can be used as a risk marker for the development of congestive heart failure (CHF) after acute MI.

Methods And Results: Plasma levels of MMP-2, MMP-9, C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-alpha), and pro-brain natriuretic peptide (pro-BNP) were measured in 109 consecutive patients with acute MI treated with primary mechanical reperfusion.

Hypoxic stress suppresses RNA polymerase III recruitment and tRNA gene transcription in cardiomyocytes.

RNA polymerase (pol) III transcription decreases when primary cultures of rat neonatal cardiomyocytes are exposed to low oxygen tension. Previous studies in fibroblasts have shown that the pol III-specific transcription factor IIIB (TFIIIB) is bound and regulated by the proto-oncogene product c-Myc, the mitogen-activated protein kinase ERK and the retinoblastoma tumour suppressor protein, RB. The principal function of TFIIIB is to recruit pol III to its cognate gene template, an activity that is known to be inhibited by RB and stimulated by ERK.

Plasma storage at -80 degrees C does not protect matrix metalloproteinase-9 from degradation.

Recently, matrix metalloproteinase-9 (MMP-9) has been identified as a cardiovascular risk marker and is increasingly being determined in clinical studies. Among other matrix metalloproteinases, MMP-9 is known to be self-activable, as the cleavage of the propeptide leads to the formation of an active enzyme. In such a case the issue of storage of biological samples such as plasmas is of outstanding importance, as an enzymatic activity, although minimal, may remain at common storage temperature, i.

Exchange protein directly activated by cAMP (EPAC) interacts with the light chain (LC) 2 of MAP1A.

Using EPAC1 (exchange protein directly activated by cAMP 1) as bait in two-hybrid screens of foetal and adult human brain libraries, we identified the LC2 (light chain 2) of MAP1A (microtubule-associated protein 1A) as a protein capable of interaction with EPAC1. We applied an immunoprecipitation assay to demonstrate protein interaction between EPAC1 and LC2 in co-transfected human embryonic kidney 293 cells. EPAC2 also co-immunoprecipitated with LC2 from extracts of rat cerebellum.