Mesenchymal progenitor cell research: limitations and recommendations

Abstract

There is considerable interest in mesenchymal stem cell biology. This relates, in part, to the possibility that such cells could be used to replace tissues in degenerative diseases of mesenchyme. In this article, the current status of the field is discussed, highlighting technical and theoretical issues related to the identification, isolation, and characterization of these cells. Our focus is the endogenous noncirculating mesenchymal stem cell populations that normally reside in adult organs.

Figure 1.

The MLG fibroblastic cell line (ATCC; American Type Culture Collection, Manassas, VA) displays multipotent differentiation capacity in vitro. Left: After placement in chondrogenic culture conditions, MLG cells form aggregated cellular structures that contain an abundance of proteoglycans as determined by positive Toluidine blue/purple stain. Middle: In osteogenic inducing medium, cells exhibit a mineralization capacity as determined by positive Alizarin Red S staining. Right: After transfer to adiopogenic conditions, Oil Red O–positive fat droplets (red) become visible.