Pig Taste Cell-derived Organoids Synthesize Insulin.

Here we describe organoid cultures derived from pig foliate taste papillae in which the cellular heterogeneity of the lingual epithelium is preserved. Pig taste organoids were maintained long term (18 passages) and continued to express taste stem cell markers (LGR4, LGR6, and SOX2) and taste receptor cell (TRC) markers (cytokeratin 20, ENTPD2, GNAT3, and OTOP1). We show insulin is necessary for optimum proliferation and differentiation of taste organoids. Some TRCs in the organoids contained insulin and the insulin-critical transcription factors MAFA and PAX4. However, we did not see any evidence of the critical glucose-responsive PDX-1 expression either in the native tissue or in the organoids. We optimized differentiation conditions for TRC expression and separately for increased insulin protein content (6.5-fold, P < .01 vs spontaneous differentiation). Insulin production in differentiated organoids was responsive to cAMP stimuli. These results provide a pig model of taste organoid culture that can be used to study taste stem cell dynamics and taste receptor cell differentiation. These findings suggest that taste organoids may serve as a novel renewable model system for studying extra-pancreatic, nonglucose-regulated insulin and its potential role as a trophic factor.