The LINC00961 transcript and its encoded micropeptide SPAAR regulate endothelial cell function

AIMS: Long non-coding RNAs (lncRNAs) play functional roles in physiology and disease, yet understanding of their contribution to endothelial cell (EC) function is incomplete. We identified lncRNAs regulated during EC differentiation and investigated the role of LINC00961 and its encoded micropeptide, small regulatory polypeptide of amino acid response (SPAAR), in EC function. METHODS AND RESULTS: Deep sequencing of human embryonic stem cell differentiation to ECs was combined with Encyclopedia of DNA Elements (ENCODE) RNA-seq data from vascular cells, identifying 278 endothelial enriched genes, including 6 lncRNAs. Expression of LINC00961, first annotated as an lncRNA but reassigned as a protein-coding gene for the SPAAR micropeptide, was increased during the differentiation and was EC enriched. LINC00961 transcript depletion significantly reduced EC adhesion, tube formation, migration, proliferation, and barrier integrity in primary ECs. Overexpression of the SPAAR open reading frame increased tubule formation; however, overexpression of the full-length transcript did not, despite production of SPAAR. Furthermore, overexpression of an ATG mutant of the full-length transcript reduced network formation, suggesting a bona fide non-coding RNA function of the transcript with opposing effects to SPAAR. As the LINC00961 locus is conserved in mouse, we generated an LINC00961 locus knockout (KO) mouse that underwent hind limb ischaemia (HLI) to investigate the angiogenic role of this locus in vivo. In agreement with in vitro data, KO animals had a reduced capillary density in the ischaemic adductor muscle after 7 days. Finally, to characterize LINC00961 and SPAAR independent functions in ECs, we performed pull-downs of both molecules and identified protein-binding partners. LINC00961 RNA binds the G-actin sequestering protein thymosin beta-4x (Tβ4) and Tβ4 depletion phenocopied the overexpression of the ATG mutant. SPAAR binding partners included the actin-binding protein, SYNE1. CONCLUSION: The LINC00961 locus regulates EC function in vitro and in vivo. The gene produces two molecules with opposing effects on angiogenesis: SPAAR and LINC00961

A Role for the Long Noncoding RNA SENCR in Commitment and Function of Endothelial Cells

Despite the increasing importance of long non-coding RNA in physiology and disease, their role in endothelial biology remains poorly understood. Growing evidence has highlighted them to be essential regulators of human embryonic stem cell differentiation. SENCR, a vascular-enriched long non-coding RNA, overlaps the Friend Leukemia Integration virus 1 (FLI1) gene, a regulator of endothelial development. Therefore, we wanted to test the hypothesis that SENCR may contribute to mesodermal and endothelial commitment as well as in endothelial function. We thus developed new differentiation protocols allowing generation of endothelial cells from human embryonic stem cells using both directed and haemogenic routes. The expression of SENCR was markedly regulated during endothelial commitment using both protocols. SENCR did not control the pluripotency of pluripotent cells; however its overexpression significantly potentiated early mesodermal and endothelial commitment. In HUVEC, SENCR induced proliferation, migration and angiogenesis. SENCR expression was altered in vascular tissue and cells derived from patients with critical limb ischemia and premature coronary artery disease compared to controls. Here, we showed that SENCR contributes to the regulation of endothelial differentiation from pluripotent cells and controls the angiogenic capacity of HUVEC. These data give novel insight into the regulatory processes involved in endothelial development and function

Impaired vascular function and repair in patients with premature coronary artery disease

Background Endothelial dysfunction is central to the pathogenesis of coronary artery disease, but the role of local and circulating endothelial progenitor cells in maintaining vascular health is poorly understood. We hypothesised that impaired local and circulating vascular repair mechanisms predispose to endothelial dysfunction and the premature onset of coronary artery disease. Methods and results Patients with premature coronary artery disease (n = 16) and healthy age- and sex-matched controls (n = 16) underwent venous occlusion plethysmography with intra-arterial infusion of acetylcholine and sodium nitroprusside. Numbers of circulating endothelial progenitor cells were directly quantified in whole blood by flow cytometry. Endothelial cells were isolated from the blood vessel wall and from peripheral blood mononuclear cells, and expanded in vitro for phenotypic and functional characterisation and analysis of microRNA expression levels. A dose-dependent increase in forearm blood flow (p < 0.001) was attenuated in response to the endothelial-dependent vasodilator acetylcholine in patients compared with controls (p = 0.03). No differences in the number of circulating endothelial progenitor cells or in the phenotype, function or microRNA expression levels of endothelial outgrowth cells isolated from blood were observed in patients and controls. Conversely, local vessel wall endothelial cells from patients had significant impairments in proliferation, adhesion and migration, and significantly reduced expression levels of microRNAs known to regulate endothelial function (miRs −10 a, −let7b, −126 and −181 b) (p < 0.05 for all). Conclusion Local vessel wall derived endothelial cells, rather than circulating endothelial progenitor cells and their progeny, are impaired in patients with vascular dysfunction and premature coronary artery disease

Flavaglines Alleviate Doxorubicin Cardiotoxicity: Implication of Hsp27

Background: Despite its effectiveness in the treatment of various cancers, the use of doxorubicin is limited by a potentially fatal cardiomyopathy. Prevention of this cardiotoxicity remains a critical issue in clinical oncology. We hypothesized that flavaglines, a family of natural compounds that display potent neuroprotective effects, may also alleviate doxorubicininduced cardiotoxicity. Methodology/Principal Findings: Our in vitro data established that a pretreatment with flavaglines significantly increased viability of doxorubicin-injured H9c2 cardiomyocytes as demonstrated by annexin V, TUNEL and active caspase-3 assays. We demonstrated also that phosphorylation of the small heat shock protein Hsp27 is involved in the mechanism by which flavaglines display their cardioprotective effect. Furthermore, knocking-down Hsp27 in H9c2 cardiomyocytes completely reversed this cardioprotection. Administration of our lead compound (FL3) to mice attenuated cardiomyocyte apoptosis and cardiac fibrosis, as reflected by a 50 % decrease of mortality. Conclusions/Significance: These results suggest a prophylactic potential of flavaglines to prevent doxorubicin-induce

The Function and Therapeutic Potential of Long Non-coding RNAs in Cardiovascular Development and Disease

The popularization of genome-wide analyses and RNA sequencing led to the discovery that a large part of the human genome, while effectively transcribed, does not encode proteins. Long non-coding RNAs have emerged as critical regulators of gene expression in both normal and disease states. Studies of long non-coding RNAs expressed in the heart, in combination with gene association studies, revealed that these molecules are regulated during cardiovascular development and disease. Some long non-coding RNAs have been functionally implicated in cardiac pathophysiology and constitute potential therapeutic targets. Here, we review the current knowledge of the function of long non-coding RNAs in the cardiovascular system, with an emphasis on cardiovascular development and biology, focusing on hypertension, coronary artery disease, myocardial infarction, ischemia, and heart failure. We discuss potential therapeutic implications and the challenges of long non-coding RNA research, with directions for future research and translational focus. Keywords: transcriptomics, RNAs, long non-coding RNAs, cardiovascular system, cardiovascular development, cardiovascular disease, vascular disease, therapy, non-coding RNA

Role of prokineticin receptor 1 signaling pathways in heart and kidney function : implication of progenitor cells

[...]Mon projet de Doctorat a donc visé à : 1. déterminer le rôle de la voie de signalisation PKR1 in vivo ; 2. la perte de la voie de signalisation PKR1 provenant de l’épicarde induit des dysfonctions cardiaques et rénales ; 3. mettre en évidence le rôle de PKR1 dans l’activation et la différentiation des cellules progénitrices.[...][...]My specific aim are the following : 1. To determine the role of PKR1 signaling pathways in vivo ; 2. To show that the inactivation of PKR1 specifically in epicardium can induce cardiac and renal disorders ; 3. To determine the role of PKR1 in activation and differentiation of progenitor cells.[...

Rôle de la voie de signalisation du récepteur -1 des prokinéticines dans la fonction cardiaque et rénale : implication des cellules progénitrices

[...]My specific aim are the following : 1. To determine the role of PKR1 signaling pathways in vivo ; 2. To show that the inactivation of PKR1 specifically in epicardium can induce cardiac and renal disorders ; 3. To determine the role of PKR1 in activation and differentiation of progenitor cells.[...][...]Mon projet de Doctorat a donc visé à : 1. déterminer le rôle de la voie de signalisation PKR1 in vivo ; 2. la perte de la voie de signalisation PKR1 provenant de l’épicarde induit des dysfonctions cardiaques et rénales ; 3. mettre en évidence le rôle de PKR1 dans l’activation et la différentiation des cellules progénitrices.[...

Évaluation de la prise en charge de l'embolie pulmonaire aux urgences

Médecine généraleIntroduction : l'embolie pulmonaire (EP) est fréquente aux urgences. Nous avons évalué la prise en charge de l’EP aux urgences. Méthode : étude rétrospective, monocentrique menée du 1/01/14 au 31/12/14 aux urgences de Strasbourg. Les critères d’inclusion étaient le diagnostic d’EP, l’âge supérieur à 18 ans. Les données suivantes étaient comparées aux directives de l’ESC : la clinique, l'utilisation des scores de probabilité, les examens complémentaires, le traitement et l’orientation des patients. Résultats : l'algorithme diagnostique a été suivi dans 72%; l'emploi des scores probabilité n’a concerné que 5% des cas. Le traitement et l'orientation hospitalière ont été conformes dans respectivement 77% et 64% des cas. Conclusion : le calcul des scores probabilité reste insuffisant. L’intégration des scores pronostiques via un logiciel informatique, la formation des urgentistes à l'échographie cardiaque et le recours à un traitement ambulatoire permettront d’améliorer la prise en charge de l'EP.Introduction : pulmonary embolism (PE) is a cause common for consultation in emergency room. We aimed to analyze the PE management. Method : a retrospective monocentric study realized from 1/01/14 to 31/12/14 at the emergency room in Strasbourg. The inclusion criteria comprised the PE diagnostic, age over 18 years. We compared following parameters to the ESC guidelines: clinical data; use of the clinical probability; complementary examination implemented; treatment ; hospital orientation. Results : the diagnostic algorithm has been followed in 72% ; the use of pretest probability was perfomed in 5% of the case. The therapeutic management and hospital orientation were in compliance respectively in 77% and 64% of the case. Conclusion : the use of pretest probability remains inadequate. The usage of the prognostic assessment via a software, the training of the physicians to the cardiac echography and the practice of home treatment may allow the progress of the PE management