Laboratoire de recherche vasculaire translationnelle
Le Laboratoire de Recherche Vasculaire Translationnelle (Laboratory for Vascular Translational Science - LVTS) est associé à l’Inserm, à l’Université Paris Diderot, et l’Université Paris 13. Il est identifié comme UMRS 1148.
Avec 5 équipes, le laboratoire d’environ 150 personnes a une approche transdisciplinaire avec les objectifs de lutte contre les pathologies vasculaires. Les équipes sont affiliées à 3 ITMO (CMN, TS, IHP), à plusieurs Ecoles doctorales du PRES Sorbonne Paris Cité, et à 2 sections scientifiques de l'Inserm (CSS4 et CSS8).
Pour mener à bien ces projets, les compétences humaines et technologiques comprennent les bases de données cliniques, enquêtes cliniques translationnelles (sténose carotidienne, anévrisme et dissections de l'aorte ascendante, Biocore ), bases de données de tissus humains et de cellules, de nombreux modèles expérimentaux de la maladie (souris transgéniques, rats , lapins), des méthodes de biologie moléculaire et cellulaire (génétique et épigénétique, protéomique, ingénierie des protéines, cytométrie en flux), la chimie des biopolymères, l’élaboration de biomatériaux et nanosystèmes, et les technologies d'imagerie chez les petits animaux et chez l'homme (imagerie nucléaire, ultrasons et IRM).
Equipes de recherche
Le projet est structuré en 5 équipes. Les objectifs mettent en évidence la complémentarité des équipes et des interfaces existantes autour d'un thème structurant sur le coeur et les vaisseaux.
- Equipe 1 : " Biologie de l'athérothrombose" (chef d'équipe : A Nicoletti) - voir aussi l'UFR Sciences du Vivant
- Equipe 2 : "Maladies structurelles cardiovasculaires" (chef d'équipe : C Boileau & G Jondeau)
- Equipe 3 : "Bio-ingénierie cardiovasculaire" (chef d'équipe : D Letourneur)
- Equipe 4 : " Imagerie cardiovasculaire" (chef d'équipe : D Le Guludec)
- Equipe 5 : "Maladies athérothrombotiques du coeur et du cerveau" (chef d'équipe : G Steg)
[inserm-01847283] Evaluation of Functionalized Polysaccharide Microparticles Dosimetry for SPECT Imaging Based on Biodistribution Data of Rats
Date: 23 Jul 2018 - 15:28
Desc: Purpose: Technetium-99 m (Tc-99 m)-labelled microparticles, functionalized with fucoidan to present a high affinity for P-Selectin, or [ 99m Tc] MP-fucoidan, were developed as a novel SPECT radiotracer for abdominal aortic aneurysm (AAA). As a prerequisite step forwards a clinical trial, the biodistribution and dosimetry of these [ 99m Tc] MP-fucoidan microparticles were performed in rats in order to estimate the absorbed and effective dose in humans. Procedures: Microparticles with a maximum hydrodynamic diameter of 4 μm were obtained by crosslinking polysaccharides dextran and pullulan. They were functionalized with fucoidan then radiolabelled with Tc-99 m. A mean labelling efficiency of 92±1 % was measured. [ 99m Tc] MP-fucoidan (43±2 MBq) was injected to 24 rats via the penis vein. Rats were euthanized at 30, 60, 120 and 240 min after injection (4 rats at each time point). Samples of each organ, as well as the injected microparticle suspensions, were aliquoted for counting. Four animals were sacrificed for blood clearance studies and four were sacrificed for image analysis and quantification of the cortical, medullary, papillary kidney, and pelvis uptake. A compartmental model was realised using SAAM II and organ data were fitted. The area under the curve was then used to compute the residence times in each rat organs and converted to human residence time values. Absorbed and effective human doses in organs were estimated using (1) the OLINDA/EXM 1.1 software with the hermaphroditic mathematical phantoms and (2) the OEDIPE software associated to the MCNPX Monte Carlo code and the ICRP reference computational male and female phantoms, using the updated tissue weighting factors in the ICRP Publication 103. Results: The highest human residence times were found in the liver, kidneys, and urinary bladder wall. The largest doses were found in the kidneys and then in the urinary bladder wall and liver. The human effective doses were 6.06 μSv/MBq for the hermaphroditic mathematical phantom and 5.95 μSv/MBq for the ICRP adult reference computational phantom. Conclusions: Animal-based human dose estimates support a future first-inhuman testing of [ 99m Tc] MP-fucoidan following IV injection.
[hal-02966416] Insights into Species Preservation: Cryobanking of Rabbit Somatic and Pluripotent Stem Cells
Date: 14 Oct 2020 - 01:04
Desc: Induced pluripotent stem cells (iPSCs) are obtained by genetically reprogramming adult somatic cells via the overexpression of specific pluripotent genes. The resulting cells possess the same differentiation properties as blastocyst-stage embryonic stem cells (ESCs) and can be used to produce new individuals by embryonic complementation, nuclear transfer cloning, or in vitro fertilization after differentiation into male or female gametes. Therefore, iPSCs are highly valuable for preserving biodiversity and, together with somatic cells, can enlarge the pool of reproductive samples for cryobanking. In this study, we subjected rabbit iPSCs (rbiPSCs) and rabbit ear tissues to several cryopreservation conditions with the aim of defining safe and non-toxic slow-freezing protocols. We compared a commercial synthetic medium (STEM ALPHA.CRYO3) with a biological medium based on fetal bovine serum (FBS) together with low (0-5%) and high (10%) concentrations of dimethyl sulfoxide (DMSO). Our data demonstrated the efficacy of a CRYO3-based medium containing 4% DMSO for the cryopreservation of skin tissues and rbiPSCs. Specifically, this medium provided similar or even better biological results than the commonly used freezing medium composed of FBS and 10% DMSO. The results of this study therefore represent an encouraging first step towards the use of iPSCs for species preservation.
[hal-03607030] Patent foramen ovale closure in stroke patients with migraine in the CLOSE trial. The CLOSE-MIG study
Date: 12 Mar 2022 - 17:01
Desc: Background and purpose The efficacy of patent foramen ovale (PFO) closure to reduce the frequency of migraine attacks remains controversial. Methods This was a planned sub-study in migraine patients enrolled in a randomized, clinical trial designed to assess the superiority of PFO closure plus antiplatelet therapy over antiplatelet therapy alone to prevent stroke recurrence in patients younger than 60 years with a PFO-associated cryptogenic ischaemic stroke. The main outcome was the mean annual number of migraine attacks in migraine patients with aura and in those without aura, as recorded at each follow-up visit by study neurologists. Results Of 473 patients randomized to PFO closure or antiplatelet therapy, 145 (mean age 41.9 years; women 58.6%) had migraine (75 with aura and 70 without aura). Sixty-seven patients were randomized to PFO closure and 78 to antiplatelet therapy. During a mean follow-up of about 5 years, there were no differences between antiplatelet-only and PFO closure groups in the mean annual number of migraine attacks, both in migraine patients with aura (9.2 [11.9] vs. 12.0 [19.1], p = 0.81) and in those without aura (12.1 [16.1] vs. 11.8 [18.4], p > 0.999). There were no differences between treatment groups regarding cessation of migraine attacks, migraine-related disability at 2 years and use of migraine-preventive drugs during follow-up. Conclusions In young and middle-aged adults with PFO-associated cryptogenic stroke and migraine, PFO closure plus antiplatelet therapy did not reduce the mean annual number of migraine attacks compared to antiplatelet therapy alone, in migraine patients both with and without aura.
[hal-02401411] Variability and Uncertainty of 18F-FDG PET Imaging Protocols for Assessing Inflammation in Atherosclerosis: Suggestions for Improvement
Date: 9 Dec 2019 - 23:55
Desc: PET with (18)F-FDG shows promise for the evaluation of metabolic activities in atherosclerotic plaques. Although recommendations regarding the acquisition and measurement protocols to be used for (18)F-FDG PET imaging of atherosclerosis inflammation have been published, there is no consensus regarding the most appropriate protocols, and the image reconstruction approach has been especially overlooked. Given the small size of the targeted lesions, the reconstruction and measurement methods might strongly affect the results. We determined the differences in results due to the protocol variability and identified means of increasing the measurement reliability.
U.F.R. de Médecine Paris Diderot (site Xavier-Bichat)
U698 Inserm - CHU Xavier Bichat
16, rue Henri-Huchard - B.P. 416
75877 PARIS CEDEX 18