Cellules souches du muscle squelettique: étude d'une population capable de différenciation multipotente
The use of stem cells is a promising approach for the treatment of neuromuscular degenerative diseases. Many studies currently focus on embryonic stem cells (ES) and induced pluripotent stem cells (IPs) for use in regenerative medicine. But some problems remain for their use in cell therapy in particular the potential of these cells to form teratomas. This problem requires both ES and IPs to be differentiated towards a specific cell type. Such induction of differentiation can lead to additional risks such as genetic drift or various sources of contamination. The adult skeletal muscle, has a high plasticity and regenerative capacity, it contains a stem cell population that is specific for muscle, and has been isolated and studied in the laboratory. Adult skeletal Muscle-Derived Stem Cells, MDSC repopulate and repair damaged skeletal muscle with high efficiency in a few days, even in the presence of endogenous satellite cells. (Arsic et al Exp. Cell Res. 2008). The host laboratory is characterizing this cell population and its histological identity and testing the tissue repair potential of transplanted MDSC in mouse models, as well as their bio-distribution for therapeutic use. My thesis work addressed the study of this stem cells population isolated from skeletal muscle showing low adhesion to substrate. Poor/low adherence is an interesting property because in addition to be defined as closer to the pluripotent state, this property is associated with a higher migration capability. This population of muscle stem cells should be easier to use than pre-differentiated stem cells in regenerative medicine. In this perspective it is interesting to use multipotent stem cells that are close to pluripotent cells in terms of differentiation and regenerative capacity, but without the inconveniencies like teratogenic risk and uncontrolled proliferation, as well as expensive and time-consuming cell culture. At the beginning of my thesis I was interested by the different populations of cells present in muscle and I focused my work on known markers of stem cells, whose presence has been established in skeletal muscle, but not clearly identified histologically. Muscle stem cells expressed the pluripotency factor Sox2, but also markers, such as BCRP1/ABCG2, Sca-1 and SSEA1. I have examined the potential of MDSC to differentiate in vitro into several cell types such as cardiac pacemaker-like cells, insulin-producing cells and cells that exhibit neuronal markers. I also focused on the possible therapeutic applications of MDSC, particularly in the case of heart rhythm problems and in the case of insulin-dependent diabetes. For these in vivo studies of the repair potential of MDSC, a single systemic injection is carried out in mouse models of the diseases. The histological recovery of injected MDSC into target organs also raises the question of the biodistribution of MDSC in the body. Therefore I spent more than a year of my doctoral thesis to address this issue and showed a targeted recruitment of MDSC to injured tissue or organs within 48h of their systemic injection.
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A Tribute to Angelos Constantinou
from
10/03/2025
until 13/03/2025
Village Club de Carry-Le-Rouet, France