E-GEOD-50103 - Unlimited in vitro expansion of adult bi-potent pancreas progenitors through the Lgr5/Rspondin axis
Released on 17 September 2013, last updated on 3 June 2014
Lgr5 marks adult stem cells in multiple adult organs and is a receptor for the Wnt-agonistic R-spondins (RSPOs). Intestinal, stomach and liver Lgr5+ stem cells grow in 3D cultures to form ever-expanding organoids, which resemble the tissues of origin. Wnt signaling is inactive and Lgr5 is not expressed under physiological conditions in the adult pancreas. However, we now report that the Wnt pathway is robustly activated upon injury by Partial Duct Ligation (PDL), concomitant with the appearance of Lgr5 expression in regenerating pancreatic ducts. In vitro, duct fragments from mouse pancreas initiate Lgr5 expression in RSPO1-based cultures, and develop into budding cyst-like structures (organoids) which expand 5-fold weekly for >40 weeks. Single isolated duct cells can also be cultured into pancreatic organoids, containing Lgr5 stem/progenitor cells that can be clonally expanded. Clonal pancreas organoids can be induced to differentiate into duct as well as endocrine cells upon transplantation, thus proving their bi-potentiality We generated arrays from whole pancreas, islet, acinar and duct (Sox9+ sorted) cells and pancreas derived cultures maintained in our defined medium. For the clustering analysis we substracted the pancreas array to all arrays. Genes 2 fold differentially expressed in the ductal array were used for the analsyis. For the genes enriched in organoid cultures compared to pancreas we substracted the organoid culture arrays to the pancreas array. Genes >2-fold differentially expressed were used for the analysis.
transcription profiling by array
Hans Clevers, Meritxell Huch