Chemically Detachable Polyelectrolyte Multilayer Platform for Cell Sheet Engineering

International audienc

Anaphylactic Shock A Form of Distributive Shock without Inhibition of Oxygen Consumption

Background: The pathophysiology of anaphylactic shock during anesthesia is incompletely characterized. It is described as distributive by analogy with septic shock (anaerobic metabolism, high tissue oxygen pressure [PtiO 2 ] values). The PtiO 2 profile and its metabolic consequences during anaphylaxis are not known. Methods: Ovalbumin-sensitized anaphylactic shock rats (n ‫؍‬ 11) were compared to nicardipine-induced hypotension rats (n ‫؍‬ 12) for systemic hemodynamics, PtiO 2 , sympathetic nervous system activation, skeletal muscle blood flow, and interstitial lactate and pyruvate concentrations using combined microdialysis and polarographic Clark-type oxygen probes. Results: In both groups, the time course and the magnitude of arterial hypotension were similar. The ovalbumin group but not the nicardipine group displayed decreased skeletal muscle blood flow (from 45 ؎ 6.2 ml ⅐ 100 g ؊1 ⅐ min ؊1 to 24.3

O2 Level Controls Hematopoietic Circulating Progenitor Cells Differentiation into Endothelial or Smooth Muscle Cells

BACKGROUND:Recent studies showed that progenitor cells could differentiate into mature vascular cells. The main physiological factors implicated in cell differentiation are specific growth factors. We hypothesized that simply by varying the oxygen content, progenitor cells can be differentiated either in mature endothelial cells (ECs) or contractile smooth muscle cells (SMCs) while keeping exactly the same culture medium. METHODOLOGY/PRINCIPAL FINDINGS:Mononuclear cells were isolated by density gradient were cultivated under hypoxic (5% O2) or normoxic (21% O2) environment. Differentiated cells characterization was performed by confocal microscopy examination and flow cytometry analyses. The phenotype stability over a longer time period was also performed. The morphological examination of the confluent obtained cells after several weeks (between 2 and 4 weeks) showed two distinct morphologies: cobblestone shape in normoxia and a spindle like shape in hypoxia. The cell characterization showed that cobblestone cells were positive to ECs markers while spindle like shape cells were positive to contractile SMCs markers. Moreover, after several further amplification (until 3(rd) passage) in hypoxic or normoxic conditions of the previously differentiated SMC, immunofluorescence studies showed that more than 80% cells continued to express SMCs markers whatever the cell environmental culture conditions with a higher contractile markers expression compared to control (aorta SMCs) signature of phenotype stability. CONCLUSION/SIGNIFICANCE:We demonstrate in this paper that in vitro culture of peripheral blood mononuclear cells with specific angiogenic growth factors under hypoxic conditions leads to SMCs differentiation into a contractile phenotype, signature of their physiological state. Moreover after amplification, the differentiated SMC did not reverse and keep their contractile phenotype after the 3rd passage performed under hypoxic and normoxic conditions. These aspects are of the highest importance for tissue engineering strategies. These results highlight also the determinant role of the tissue environment in the differentiation process of vascular progenitor cells

Pattern recognition receptors in immune disorders affecting the skin.

Contains fulltext : 109004.pdf (publisher's version ) (Open Access)Pattern recognition receptors (PRRs) evolved to protect organisms against pathogens, but excessive signaling can induce immune responses that are harmful to the host. Putative PRR dysfunction is associated with numerous immune disorders that affect the skin, such as systemic lupus erythematosus, cryopyrin-associated periodic syndrome, and primary inflammatory skin diseases including psoriasis and atopic dermatitis. As yet, the evidence is often confined to genetic association studies without additional proof of a causal relationship. However, insight into the role of PRRs in the pathophysiology of some disorders has already resulted in new therapeutic approaches based on immunomodulation of PRRs

Terrestrial very-long-baseline atom interferometry: Workshop summary

This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more kilometer–scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions

Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary

This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions

Terrestrial very-long-baseline atom interferometry: Workshop summary

This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more kilometer--scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions

Terrestrial Very-Long-Baseline Atom Interferometry : summary of the second workshop

This summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024 (Second Terrestrial Very-Long-Baseline Atom Interferometry Workshop, Imperial College, April 2024), building on the initial discussions during the inaugural workshop held at CERN in March 2023 (First Terrestrial Very-Long-Baseline Atom Interferometry Workshop, CERN, March 2023). Like the summary of the first workshop (Abend et al. in AVS Quantum Sci. 6:024701, 2024), this document records a critical milestone for the international atom interferometry community. It documents our concerted efforts to evaluate progress, address emerging challenges, and refine strategic directions for future large-scale atom interferometry projects. Our commitment to collaboration is manifested by the integration of diverse expertise and the coordination of international resources, all aimed at advancing the frontiers of atom interferometry physics and technology, as set out in a Memorandum of Understanding signed by over 50 institutions (Memorandum of Understanding for the Terrestrial Very Long Baseline Atom Interferometer Study)

Comparaison de la capacité de différenciation en cellules endothéliales, de deux types de cellules souches mésenchymateuses issues de la gelée de Wharton et de la moelle osseuse

L'incidence des maladies cardiovasculaires d'origine athéromateuse constitue un problème majeur en santé publique et malgré le développement de techniques curatives endovasculaires, la chirurgie demeure nécessaire chez de nombreux patients. La faible disponibilité des vaisseaux naturels, autologues ou non, et les limites mécaniques et biologiques des substituts artificiels pour le remplacement des vaisseaux de petit calibre, imposent le recours à une nouvelle science : l'ingénierie vasculaire. Ce concept a émergé et évolué depuis quelques années. Il pourrait permettre de proposer de nouveaux types de substituts vasculaires synthétiques et/ou biologiques, en particulier grâce à l'utilisation de cellules souches, ouvrant d'intéressantes perspectives dans le domaine de l'ingénierie vasculaire. Le but de ce travail a été d'obtenir de manière fiable et reproductible des cellules à phénotype endothélial mature à partir de cellules souches mésenchymateuses (CSMs) issus de la gelée de Wharton (GW) du cordon ombilical et de la moelle osseuse (MO). Cependant, la différenciation de ces cellules nécessite une fonctionnalisation de la surface de culture, et notre groupe a démontré l'avantage des films multicouches de polyélectrolytes, constitués de PAH (hydrochlorure de poly(allylamine)) et de PSS (poly(styrène sulfonate)), sur l'adhésion, la prolifération et la différenciation cellulaire. Les cellules ont été cultivées sur films (PAH-PSS)4 ou sur collagène de type I (témoin), en présence de facteurs de croissance angiogéniques. La différenciation en cellules endothéliales (CEs) a été suivie par l'expression des marqueurs endothéliaux (PCR et western blot), et la fonctionnalité par leur capacité à incorporer les lipoprotéines acétylées (Ac-LDLs) ainsi que la capacité à produire du monoxyde d'azote et à exprimé le facteur von Willebrand (vWF). Après 14 jours de stimulation, seules les CSM-GWs étaient différenciées en CEs fonctionnelles démontrant l'intérêt de combiner l'utilisation des CSM-GWs et des films (PAH-PSS)4 dans le domaine de l'ingénierie vasculaireThe incidence of cardiovascular disease remains a major public health problem. Despite the development of endovascular therapies, surgical treatment is necessary for many patients. The low availability of natural vessels, autologous or not, and the mechanical and biological limits of artificial substitutes, led to the use of a new domain: vascular engineering. In recent years, the concept has emerged and evolved. He could afford to offer new types of synthetic vascular substitutes and / or biological, in particular through the use of stem cells, offering interesting perspectives in the field of vascular engineering. The purpose of this study was to obtain a reliable and reproducible protocol to generate functional endothelial cells (ECs) from mesenchymal stem cells (MSCs) derived from the umbilical cord Wharton's jelly (WJ) and bone marrow (BM). Nevertheless, their differentiation into vascular cells needs a culture surface functionalization; our group demonstrated the potential use of polyelectrolyte multilayer made of poly(allylamine hydrochloride): PAH, and poly(styrene sulfonate): PSS, in promoting cells adhesion, proliferation and differentiation. Cells were cultured on (PAH-PSS)4 films or collagen type I (used as control), in the presence of angiogenic growth factors. Cells differentiation into EC was followed through the expression of endothelial markers (PCR and western blot); cell functionality was checked through their ability to incorporate acetylated LDL (Low Density Lipoprotein), to produce NO (Nitric oxide) and to express the von Willebrand factor (vWF). After 14 days of stimulation, only WJ-MSCs were able to generate functional ECs demonstrating the potential of combining WJ-MSCs and (PAH-PSS)4 films in vascular tissue engineering fieldNANCY-INPL-Bib. électronique (545479901) / SudocSudocFranceF