Poster #072, UC Davis Health System
Researching the effect of Therapeutics on both Mesenchymal Stem Cell Proliferation and Differentiation
Mentors: Anisha Kandala, PhD Candidate and Fernando Fierro, PhD
Fibrous Dysplasia (FD) is a rare skeletal disorder characterized by scar-like tissue instead of normal bone, weakening it and making it prone to fractures, abnormalities, and pain. FD is caused by a missense mutation in the GNAS1 gene, which encodes the alpha subunit of the stimulatory G protein-coupled receptor (Gsa). The responsible mutations are GsaR201H and GsaR201C, where histidine or cysteine replaces the normal amino acid arginine. When the mutation occurs, the alpha subunit continuously stimulates cyclic adenosine monophosphate (cAMP) production. However, the relationship between this increase in cAMP and the FD phenotype remains unknown. The disease spreads during fetal development and usually affects a single bone (monostotic), though it can affect multiple bones (polyostotic).
In my research, I examined the drugs Atomwise 53, along with Geldanamycin (GA) and Bortezomib (BZ), which were hypothesized to prevent the alpha subunit from binding to Gsa, preventing the FD phenotype. I used Mesenchymal Stem Cell (MSC) models in MTT proliferation and an Alkaline Phosphotase Activity (ALP) assay. My MTT experiment involved human bone marrow-derived MSCs lentivirally transduced with wild-type Gsa and GsaR201H. The drugs tested were GA at 10nM, BZ at 10nM, and Atomwise 53 at 10nM. Results showed a slight reduction in absorption in cells cultured with Atomwise 53, while GA and BZ cultures exhibited extremely low absorption. Lower absorbance indicates reduced cellular metabolism and viability. Thus, cells cultured in Atomwise 53 showed only a small decrease in cell viability, whereas GA and BZ exhibited high toxicity.
Similarly, my ALP experiment used wild-type MSCs and a GsaR201H variant. These cells were grown in media with GA, BZ, and Atomwise 53, each at 10nM. The ALP results revealed changes in alkaline phosphate activity in cells treated with Atomwise 53, compared to healthy controls.