Use of proteomic differential displays to assess functional discrepancies and adjustments of human bone marrow- and Wharton jelly-derived mesenchymal stem cells.

Mesenchymal stem cells (MSCs) from bone marrow are suitable for the reconstruction of connective tissues and even brain tissue but have limitations in terms of cell expansion and fully specific differentiation. In our current study, we have attempted to adjust and improve the cell expansion and differentiation properties of human MSCs from different tissues. MSCs from normal bone marrow and Wharton jelly were subjected to proteomic differential displays, followed by functional adjustments based on these displays. Bone marrow MSCs expressed more transgelin-2 and differentiated more rapidly into bone nodules but showed a slower growth rate. A knockdown of transgelin-2 expression by specific small interfering RNA (siRNA) significantly increased the growth rate of these cells, the G1/S phase cell cycle transition, and the interaction of cyclin D1 with cdk2. Wharton jelly MSCs expressed the chaperone protein HSP90 beta at higher levels and differentiated slowly toward an osteogenic lineage. However, the knockdown of HSP90 beta expression significantly increased bone nodule formation, inhibited cell growth, decreased the number of cells in the G1/S phase of the cell cycle, and decreased the interaction of cyclin D1 with cdk2 and of cyclin E with cdk2. These results were validated by the in vivo repair of segmental bone defects in a mouse model with severe combined immunodeficiency. We thus demonstrate an improvement in the cell expansion and tissue regeneration properties of human MSCs through specific adjustments.