Derivation of Parathyroid Gland Cells and Their Progenitors from Induced Pluripotent Stem Cells (iPSCs) for Personalized Therapy

This research addresses metabolic pathologies resulting from hypoparathyroidism, parathyroid disease, and injury. The major goals of the project were to establish genetically modified primary parathyroid cell lines, develop protocols to differentiate pluripotent stem cell lines into parathyroid tissues using a genetically marked pluripotent stem cell line, and demonstrate efficient transplantation of in vitro differentiated parathyroid tissues in a hypoparathyroid mouse model. This report discusses the successful creation of an induced pluripotent stem cell line with a red fluorescent protein marker inserted into the GCM2gene. GCM2 is a unique marker expressed in parathyroid tissues and serves as an easily detected reporter for cells that have differentiated into parathyroid tissues. A novel recombination product was identified in these experiment that has not been reported for iPS cell lines or for gene modifications using CRISPR/Cas9. Several growth conditions and substrates for growth of parathyroid primary cells have been tested that have supported short-term growth, but not apparent long term survival, of parathyroid primary cell lines in culture. Three different induced pluripotent stem cell lines have been used to test in vitro differentiation protocols to generate parathyroid tissue. These experiments have met with mixed success as demonstrated by the transient expression of parathyroid hormone and GCM2, both markers of parathyroid tissues.