Stem Cell Derived Osteoprogenitors and Their Role in Bone Repair Using Morphogenic Activators
George Washington Brownridge III Sylvanna Islas Angelina Miller Warren Hoeffler
Dominican University of California
Bone constantly cycles through a dynamic process of breakdown and remodeling. Osteoblasts are the specialized mesenchymal stem cells that have a major role in bone formation and the remodeling process..
Bone constantly cycles through a dynamic process of breakdown and remodeling. Osteoblasts are the specialized mesenchymal stem cells that have a major role in bone formation and the remodeling process whereas their counterpart osteoclasts, handle bone resorption. Embryonic stem cells can be partially differentiated into Progenitor cells, and we worked with #18, a candidate for being an osteoprogenitor that has the potential to respond to morphogenic activators. In the case of bone remodeling, TGF-β 2, BMP-2 and an abundance of CA++ have been shown to be potential activators of differentiation into osteoblasts. Eight different trials were conducted with the cells using different combinations of the three morphogenic activators. After inducing the cells with the activators, we performed Immunohistochemistry (IHC) to analyze the expression of osteocalcin, which is the enzyme that binds calcium to mineralize bone. The cells with varying activator combinations showed different physiology with a variance in the cell shape, structure, and spacing. The greatest results were from the combination of TGF-β 2 and BMP-2, which is consistent with #18 operating as an osteoprogenitor. A 3D construct model of #18 seemed to have a similar structure to that of an osteon, possibly indicating the formation of bone. We took slices of the model and performed an IHC staining for Osteocalcin, Prolyl Hydroxylase (5B5), and Collagen I. We saw a strong positive signal for Col I and 5B5, and a slight positive signal for Osteocalcin. This information confirmed that #18 is an osteoprogenitor and is able to assemble bone.