Cold Shock and Cold Acclimation Proteins in the Psychrotrophic Bacterium Arthrobacter globiformis SI55

The psychrotrophic bacterium Arthrobacter globiformis SI55 was grown at 4 and 25 degrees C, and the cell protein contents were analyzed by two-dimensional electrophoresis. Cells subjected to cold shocks of increasing magnitude were also analyzed. Correspondence analysis of protein appearance distinguished four groups of physiological significance. Group I contained cold shock proteins (Csps) overexpressed only after a large temperature downshift. Group II contained Csps with optimal expression after mild shocks. Group III contained proteins overexpressed after all cold shocks. These last proteins were also overexpressed in cells growing at 4 degrees C and were considered to be early cold acclimation proteins (Caps). Group IV contained proteins which were present at high concentrations only in 4 degrees C steady-state cells and appeared to be late Caps. A portion of a gene very similar to the Escherichia coli cspA gene (encoding protein CS7.4) was identified. A synthetic peptide was used to produce an antibody which detected a CS7.4-like protein (A9) by immunoblotting two-dimensional electrophoresis gels of A. globiformis SI55 total proteins. Unlike mesophilic microorganisms, this CS7.4-like protein was still produced during prolonged growth at low temperature, and it might have a particular adaptive function needed for balanced growth under harsh conditions. However, A9 was induced at high temperature by chloramphenicol, suggesting that CS7.4-like proteins have a more general role than their sole implication in cold acclimation processes

Small Vessel Replacement by Human Umbilical Arteries With Polyelectrolyte Film-Treated Arteries In Vivo Behavior

ObjectiveThe aim of this study was to evaluate the patency of human umbilical arteries treated with polyelectrolyte multilayers (PEMs) after rabbit implantation.BackgroundThe development of small-caliber vascular substitutes with high patency after implantation remains a real challenge for vascular tissue engineering.MethodsCryopreserved human umbilical arteries were enzymatically de-endothelialized and the luminal surfaces were coated with poly(styrene sulfonate)/poly(allylamine hydrochloride) (PSS/PAH) multilayers. The PEM-untreated arteries and PEM-treated rabbit carotids were used as graft control. The native rabbit carotids were bypassed by grafts.ResultsThe Doppler ultrasound evaluation, performed in vivo, showed that all PEM-treated grafts remained patent during the full experimental period, whereas after only 1 week, no blood circulation was detected in untreated arteries. Scanning electron microscopy and histological graft examination showed pervasive thrombus formation on the luminal surface of untreated arteries after 1 week and clean luminal surface for treated arteries for at least up to 12 weeks. The arterial wall cells were identified through alpha-smooth muscle actin αυδ platelet endothelial cell adhesion molecule-1 expression. The smooth muscle cells positive to alpha-smooth muscle actin were identified in adventitia and media and the endothelial cells positive to platelet endothelial cell adhesion molecule in intima. Von Kossa reaction didn't reveal any calcium salt deposits on the wall arteries, suggesting a good wall remodelling with no sign of graft rejection.ConclusionsThe in vivo evaluation of human umbilical arteries treated with PSS/PAH multilayers demonstrated a high graft patency after 3 months of implantation. Such modified arteries could constitute a useful option for small vascular replacement

Chemically Detachable Polyelectrolyte Multilayer Platform for Cell Sheet Engineering

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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 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

How to Evaluate Blood Substitutes for Endothelial Cell Toxicity

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Réponse aux antidépresseurs et polymorphisme du gène ABCB1

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

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