Dozentin: Dr. Anja Saalbach, Universitätsklinikum Leipzig AöR, Department für Innere Medizin, Neurologie und Dermatologie, Klinik für Dermatologie, Venerologie und Allergologie
Thy-1 (CD90) is expressed on cell surface of mesenchymal stem cells (MSCs), fibroblasts, activated microvascular endothelial cells, neurons, and mouse T-cells. Here, we investigated the impact of Thy-1 expressed on MSCs for fate decision between osteogenic and adipogenic differentiation and consequences for bone formation and adipose tissue development. MSCs from Thy-1-deficient mice have a decreased potential of osteoblastic differentiation combined with a concurrent increase in adipogenic differentiation compared to MSCs from wildtype mice. Consistently, Thy-1-deficient mice exhibited decreased bone volume, bone formation rate, and an elevated cortical porosity resulting in lower bone strength. In parallel, body weight, fat mass, and bone fat volume were concurrently increased. Our data identified Thy-1 as a critical molecule on MSCs promoting osteogenesis and thus bone formation while inhibiting adipogenesis and obesity.