ROCK Inhibitor Increases Proacinar Cells in Adult Salivary Gland Organoids

Abstract

Salisphere-derived adult epithelial cells enriched for progenitor cells have been used to improve saliva production of irradiated mouse salivary glands. Importantly, optimization of the cellular composition of salispheres could improve their regenerative capabilities. The Rho Kinase (ROCK)1 inhibitor, Y27632, has been used to increase the proliferation and reduce apoptosis of progenitor cells grown in vitro. In this study, we investigated whether Y27632 in different cell media contexts could be used to improve expansion of adult epithelial progenitor cells or to affect their differentiation potential. Application of Y27632 in medium used previously to grow salispheres promoted expansion of Kit+ cells, while in simple serum-containing medium Y27632 increased the number of cells that expressed the K5 basal progenitor marker. When tested in a 3D organoid assay, Y27632 enhanced the contribution of adult salispheres to salivary organoids expressing the secretory proacinar marker Aquaporin 5 (AQP5) in response to FGF2 dependent mesenchymal signals. Optimization of epithelial-mesenchymal interactions organoids can be used to improve application of adult salivary progenitor cells in regenerative medicine strategies.\n\nHighlightsO_LIY27632 promotes Kit+ salisphere cell proliferation in salisphere media.\nC_LIO_LIY27632 promotes K5 expression in salispheres cultured in serum containing media.\nC_LIO_LIY27632 treated Kit+ salispheres form salivary organoids expressing AQP5.\nC_LI