Scientists Identified the Role of Osteopontin for Mesenchymal Stem Cells
As a kind of stem cells , mesenchymal stem cells (MSCs) play an important role in the repair of damaged tissue due to its differentiation potential, and it has broad application prospects in the field of regenerative medicine.
In recent years, many studies agree that the MSCs in bone marrow are the common precursor cells of adipocytes and osteoblasts. Thus, there is a competition balance between bone and fat, and the alteration of the balance is closely associated with various metabolic diseases. For example, in the marrow of patients with osteoporosis and reduced amount of bone marrow, their fat content are significantly higher than the healthy control group’s. However, the role of adipogenic osteogenic differentiation of MSCs imbalance remains unclear for the pathological processes in these diseases.
Scientists found that MSCs deletion of osteopontin (OPN) is easy to carry adipogenic differentiation, while the osteogenic differentiation capacity is significantly weakened. The lack of OPN in the whole mouse embryos development can cause a lot of physiological changes. In order to prove the direct effect of OPN on the MSCs differentiated phenotype, they use shRNA with specific OPN knockout to prove it. Combining OPN-specific neutralizing antibody binding experiments and exogenous OPN experimental study, the study further demonstrated that extracellular form of OPN also plays an important role in regulating the differentiation of MSCs, which depends on OPN receptors integrin αv/β1 as well as the C/EBPs signaling pathways, thereby regulating adipogenic osteogenic differentiation. In vivo studies found that although the fat cells of mice in bone and marrow are normal, but the body fat of mice with OPN missing was significantly higher than that of wild-type mice.
So far, this is the first study that reveals an important regulatory role of OPN in MSCs adipogenic osteogenic differentiation balance.