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Dempsey, P. J.

Publications and source records attributed to Dempsey, P. J..

2 recordsLinked to original sources

Fully synthetic hydrogels promote robust crypt formation in intestinal organoids

Initial landmark studies in the design of synthetic hydrogels for intestinal organoid culture identified precise matrix requirements for differentiation, namely decompression of matrix-imposed forces and supplementation of laminin. But beyond stating the necessity of laminin, organoid-laminin interactions have gone largely unstudied, as this ubiquitous requirement of exogenous laminin hinders investigation. In this work, we exploit a fast stress relaxing, boronate ester based synthetic hydrogel for the culture of intestinal organoids, and fortuitously discover that unlike all other synthetic hydrogels to date, laminin does not need to be supplemented for crypt formation. This highly defined material provides a unique opportunity to investigate laminin-organoid interactions and how it influences crypt evolution and organoid function. Via fluorescent labeling of non-canonical amino acids, we further show that adaptable boronate ester bonds increase deposition of nascent proteins, including laminin. Collectively, these results advance the understanding of how mechanical and matricellular signaling influence intestinal organoid development.

bioengineering↗

High Sox2 expression predicts taste lineage competency of lingual progenitors in vitro.

SO_SCPLOWUMMARYC_SCPLOWTaste buds on the tongue are collections of taste receptor cells (TRCs) that detect sweet, sour, salty, umami and bitter stimuli. Like non-taste lingual epithelium, TRCs are renewed from basal keratinocytes, many of which express the transcription factor SOX2. Genetic lineage tracing has shown SOX2+ lingual progenitors give rise to both taste and non-taste lingual epithelium in the posterior circumvallate taste papilla (CVP) of mice. However, SOX2 is variably expressed among CVP cells suggesting that their progenitor potential may vary. Using transcriptome analysis and organoid technology, we show highly expressing SOX2+ cells are taste-competent progenitors that give rise to organoids comprising both TRCs and lingual epithelium, while organoids derived from low-expressing SOX2+ progenitors are composed entirely of non-taste cells. Hedgehog and WNT/{beta}-catenin are required for taste homeostasis in adult mice, but only WNT/{beta}-catenin promotes TRC differentiation in vitro and does so only in organoids derived from higher SOX2+ taste lineage-competent progenitors.

developmental biology↗