Ari Massoudi

Les cellules souches et la thérapie cellulaire génèrent un engouement certain aussi bien pour les biologistes que pour les cliniciens et le grand public. La recherche fondamentale en biologie du développement, en utilisant les cellules souches comme modèle d'étude permet d'aborder les régulations et mécanismes tant cellulaires que moléculaire impliquées au cours de l'embryogenèse, de l'histogenèse foetale et de l'histogenèse adulte au cours du renouvellement tissulaire normal ou après une… Mehr anzeigen

Les cellules souches et la thérapie cellulaire génèrent un engouement certain aussi bien pour les biologistes que pour les cliniciens et le grand public. La recherche fondamentale en biologie du développement, en utilisant les cellules souches comme modèle d'étude permet d'aborder les régulations et mécanismes tant cellulaires que moléculaire impliquées au cours de l'embryogenèse, de l'histogenèse foetale et de l'histogenèse adulte au cours du renouvellement tissulaire normal ou après une nécrose tissulaire. Le nombre de laboratoires s'intéressant à l'étude des cellules souches ne cesse de croître, il y a d'ores et déjà une répercutions sur l'enseignement supérieure et la formation au niveau des filières des sciences de le vie et de la santé. Ce présent manuel présentera les cellules souches et leurs applications actuelles et futures en thérapie chez l'Homme. L'ensemble des connaissances, définitions, concepts et théories autour de ces cellules, parfois fortement en contradiction sur la scène de la recherche sera également abordé et discuté. Weniger anzeigen

Cell-based therapies are used to treat bone defects. We recently described that human multipotent adipose-derived stem (hMADS) cells, which exhibit a normal karyotype, self renewal, and the maintenance of their differentiation properties, are able to differentiate into different lineages. Herein, we show that hMADS cells can differentiate into osteocyte-like cells. In the presence of a low amount of serum and EGF, hMADS cells express specific molecular markers, among which alkaline phosphatase,… Mehr anzeigen

Cell-based therapies are used to treat bone defects. We recently described that human multipotent adipose-derived stem (hMADS) cells, which exhibit a normal karyotype, self renewal, and the maintenance of their differentiation properties, are able to differentiate into different lineages. Herein, we show that hMADS cells can differentiate into osteocyte-like cells. In the presence of a low amount of serum and EGF, hMADS cells express specific molecular markers, among which alkaline phosphatase, CBFA-1, osteocalcin, DMP1, PHEX, and podoplanin and develop functional gap-junctions. When loaded on a hardening injectable bone substitute (HIBS) biomaterial and injected subcutaneously into nude mice, hMADS cells develop mineralized woven bone 4 weeks after implantation. Thus hMADS cells represent a valuable tool for pharmacological and biological studies of osteoblast differentiation in vitro and bone development in vivo. Weniger anzeigen

Mesenchymal stem cells have an intrinsic capacity to differentiate into various cell types in culture or after transplantation. Previously we have shown that multipotent stem cells derived from human adipose tissue (hMADS cells) were able to restore dystrophin expression after transplantation in mdx mice. In the current study, we investigated the mechanism of skeletal muscle phenotype acquisition by hMADS cells. We first tested various culture conditions to induce an intrinsic myogenic program… Mehr anzeigen

Mesenchymal stem cells have an intrinsic capacity to differentiate into various cell types in culture or after transplantation. Previously we have shown that multipotent stem cells derived from human adipose tissue (hMADS cells) were able to restore dystrophin expression after transplantation in mdx mice. In the current study, we investigated the mechanism of skeletal muscle phenotype acquisition by hMADS cells. We first tested various culture conditions to induce an intrinsic myogenic program in hMADS cells. Neither myotube formation nor Pax7, myf-5, MyoD and myogenin expression could be detected under these conditions. In contrast, when co-cultured with myoblasts, hMADS cells reproducibly contributed to hybrid myotube formation, expressed several muscle differentiation markers and had the ability to restore dystrophin expression in human dystrophic background. Interestingly, this myogenic conversion was not associated with the expression of key transcription factors for muscle determination/differentiation. Therefore, our results clearly demonstrated that acquisition of myogenic identity by hMADS cells did not occur via a bona fide determination/differentiation process. We propose a model of myogenic conversion of human mesenchymal stem cells derived from adipose tissue in which, only after fusion, transcription factors of myoblasts were able to program hMADS genome toward the skeletal muscle lineage. Weniger anzeigen