D028 L’expression des gènes PAI-1, tPA et uPA est fortement régulée pendant la différenciation des cellules souches embryonnaires en myocytes et adipocytes

PAI-1 est l’inhibiteur physiologique des activateurs du plasminogène uPA et tPA et inhibe le complexe formé entre uPA et son récepteur, et par voie de conséquence, entre la vitronectine et l’intégrine alphav beta3. PAI-1 est impliqué dans l’adhésion et la migration des cellules endothéliales, dans la différenciation adipocytaire et dans la réponse à l’insuline; in vivo, il facilite la thrombose, la fibrose et le remodelage tissulaire. Des taux élevés circulants de PAI-1 représentent un biomarqueur de l’obésité centrale et sont un facteur pronostic du diabète de type 2. Les propriétés biologiques de PAI-1 ont conduit à l’hypothèse que PAI-1 serait impliqué directement dans le développement du tissu adipeux. Notre objectif est d’évaluer les rôles spécifiques des gènes PAI-1, uPA et tPA dans les mécanismes moléculaires de la différenciation des cellules souches embryonnaires (cellules ES) de souris dans différents lignages.Indétectables à l’état indifférencié, les expressions de PAI-1, uPA et tPA et les activités enzymatiques uPA et tPA sont fortement régulées durant la différenciation des cellules ES. Les activités uPA et tPA sont rapidement augmentées durant la phase précoce de détermination du processus, sans expression détectable de PAI-1. Puis, l’expression de PAI-1 augmente progressivement dans les surnageants de culture des cellules bien différenciées, corrélant avec une inhibition concomittante des activités uPA et tPA. Des expériences d’immunohistochimie montrent que PAI-1 est exprimé à la fois dans les myotubes et dans les adipocytes matures.Le rôle potentiel de ces régulations successives est analysé par la construction de lignées de cellules ES surexprimant le cDNA de PAI- 1 dès l’état indifférencié. Les effets d’une surexpression ectopique de PAI-1 à différent temps pendant la différenciation des cellules ES sont recherchés.De plus, le traitement précoce des cellules ES en différenciation par l’amiloride, inhibiteur spécifique d’uPA, provoque une diminution de la myogénèse et une augmentation de la différenciation adipocytaire. Par contre ces effets ne sont pas retrouvés en traitant les cellules par l’EACA, inhibiteur de la plasmine ou le DMA, un dérivé inactif de l’amiloride

Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study

Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Changement rural en Europe : programme de recherche sur les structures des exploitations agricoles et leur pluriactivité : Le développement socio-économique des hautes vallées savoyardes : première étude de contexte.

The Savoy high valleys -Tarentaise, Maurienne and Arve valley - have been characterized, at the beginning of the century, by a high industrial development. Starting in the 70's, a slowdown was observed. However, during many years, through the creation of an important class of workers-farmers, this sector of activity has helped maintain the population level in spite of the rural exodus. On another hand, since 1950, the rapid development of winter sports has helped develop 61 ski stations and 500000 beds, which generate mainly seasonal job offers in the tertiary sector. The UTN policy has helped develop integrated stations. The recent Mountain Law recommends the return to a balanced development. The strong 19th century mountain agricultural activity was based on a milk production transformed into cheeses, on the use of altitude pastures (1800-2000m), on a complementarity between " alp " and sedentary farmers. After a long decline period, this activity has been restarted during the last twenty years, thanks to the introduction and progression of mechanization, to the collective organization of production and commercialization of cheeses, to the enforcement of a specific mountain policy. The family pluriactivity remains strong in these valleys, with the combination of varied activities, often related to tourism. Municipalities have otherwise taken steps to support farmers or to favour complementary incomes. / Les hautes vallées savoyardes-Tarentaise, Maurienne, et vallée de l'Arve ont été caractérisées,au début du siècle, par un fort développement industriel. A partir des années 70, on assiste à un reflux. Néanmoins, pendant plusieurs décennies, ce secteur d'activité a contribué, par la création d'une classe importante d'ouvriers-paysans, au maintien de la population face à l'exode rural. Par ailleurs, le développement explosif des sports d'hiver, depuis 1950, a permis la création de 61 stations de ski et 500 000 lits, générant une offre d'emplois principalement saisonniers dans le secteur tertiaire. La politique des UTN a favorisé le développement des stations intégrées. La récente Loi Montagne prône le retour à un développement équilibré. La forte activité agricole montagnarde du 19ème siècle, était fondée sur une production laitière transformée en fromages, l'utilisation des pâturages d'altitude(1800-2000m), une complémentarité entre éleveurs "alpagistes" et paysans sédentaires. Après une longue période de déclin, cette activité a été relancée, au cours des vingt dernières années, grâce à l'introduction et à la progression de la mécanisation, à l'organisation collective de la production et de la commercialisation des fromages, à la mise en place d'une politique spécifique de la montagne. La pluriactivité familiale reste forte dans ces vallées, avec la combinaison d'activité variées, notamment en liaison avec le tourisme. Les communes ont par ailleurs pris de nombreuses mesures pour soutenir les agriculteurs ou favoriser des revenus complémentaires

Contribution to accurate Spherical Gold Nanoparticles analysis (size, size distribution) by SpICPMS and SAXS

International audienceSmall-Angles X-Ray Scattering (SAXS) has been established as a metrological method for the determination of nanoparticles size and size distribution. Modern SAXS Laboratory experiments, by involving synchrotron-based instrumentation at lower price and very stable X-ray source, are more and more used in nanomaterials domain. In the frame of the EMPIR Innanopart project, we have developed a methodology for the size, size distribution and concentration determination of spherical nanoparticles. This protocol involves a precise sample preparation, and a set of homemade software tools for the data processing-from the acquisition, the absolute scaling, to the analysis. spICPMs is not a metrological traceable technique but has many strengths to become a useful complement of nanoparticle characterization methods such as SAXS and microscopy. It can also measure highly diluted nanoparticles suspensions which is not the case of Dynamic Light scattering (DLS) or SAXS. Finally, ICPMS analyzes inorganic ions in liquid solution in a very large range of concentration, which should allow linear diameter measurement range over at least 3 orders of magnitude. In this work, we confront spICPMS with SAXS in order to investigate the method and the developed protocols on a set of commercial spherical Gold Nanoparticles. Comparison between SAXS and spIPCMS method for the determination of size of spherical Gold Nanoparticle

L'analyse systémique et la modélisation de systèmes dynamiques, outils de connaissance et de gestion de l'environnement = Systemic analysis and modelling of dynamic systems, a tool for knowledge and management of the environment

Showing the benefits of the systemic approach and dynamic system modelling to environment management. Application to various examples: " Development - protection and management of mountainous areas in the Tarentaise region ", " Chartreuse Landscapes ", and " multi-use in the Mercantour Park ". In particular, contribution to the analysis and modelling of socio-political and economical mechanisms of regulation between development and protection logics. / Illustration de l'apport de l'approche systémique et de la modélisation des systèmes dynamiques à la réflexion sur la gestion de l'environnement. Application à divers exemples : "Développement - protection et gestion des milieux montagnards en Tarentaise", "Paysages de Chartreuse" et "Multi-usages dans le Parc du Mercantour". En particulier, contribution à l'analyse et à la modélisation des mécanismes socio-politiques et économiques de la régulation entre logiques de développement et de protection

The ACVR1 R206H mutation found in fibrodysplasia ossificans progressiva increases human induced pluripotent stem cell-derived endothelial cell formation and collagen production through BMP-mediated SMAD1/5/8 signaling

BACKGROUND: The Activin A and bone morphogenetic protein (BMP) pathways are critical regulators of the immune system and of bone formation. Inappropriate activation of these pathways, as in conditions of congenital heterotopic ossification, are thought to activate an osteogenic program in endothelial cells. However, if and how this occurs in human endothelial cells remains unclear. METHODS: We used a new directed differentiation protocol to create human induced pluripotent stem cell (hiPSC)-derived endothelial cells (iECs) from patients with fibrodysplasia ossificans progressiva (FOP), a congenital disease of heterotopic ossification caused by an activating R206H mutation in the Activin A type I receptor (ACVR1). This strategy allowed the direct assay of the cell-autonomous effects of ACVR1 R206H in the endogenous locus without the use of transgenic expression. These cells were challenged with BMP or Activin A ligand, and tested for their ability to activate osteogenesis, extracellular matrix production, and differential downstream signaling in the BMP/Activin A pathways. RESULTS: We found that FOP iECs could form in conditions with low or absent BMP4. These conditions are not normally permissive in control cells. FOP iECs cultured in mineralization media showed increased alkaline phosphatase staining, suggesting formation of immature osteoblasts, but failed to show mature osteoblastic features. However, FOP iECs expressed more fibroblastic genes and Collagen 1/2 compared to control iECs, suggesting a mechanism for the tissue fibrosis seen in early heterotopic lesions. Finally, FOP iECs showed increased SMAD1/5/8 signaling upon BMP4 stimulation. Contrary to FOP hiPSCs, FOP iECs did not show a significant increase in SMAD1/5/8 phosphorylation upon Activin A stimulation, suggesting that the ACVR1 R206H mutation has a cell type-specific effect. In addition, we found that the expression of ACVR1 and type II receptors were different in hiPSCs and iECs, which could explain the cell type-specific SMAD signaling. CONCLUSIONS: Our results suggest that the ACVR1 R206H mutation may not directly increase the formation of mature chondrogenic or osteogenic cells by FOP iECs. Our results also show that BMP can induce endothelial cell dysfunction, increase expression of fibrogenic matrix proteins, and cause differential downstream signaling of the ACVR1 R206H mutation. This iPSC model provides new insight into how human endothelial cells may contribute to the pathogenesis of heterotopic ossification. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13287-016-0372-6) contains supplementary material, which is available to authorized users

NF-kappa B/MAPK activation underlies ACVR1-mediated inflammation in human heterotopic ossification

Immunogenetics and cellular immunology of bacterial infectious disease