We first determined the expression and localization of some known solute carriers as well as of the bile acid receptor TGR5 in polarized SI organoids by immunofluorescent staining (Fig. Transport function was determined with radiolabeled substrates and quantification of tracer uptake into organoid enterocytes.Since the (inner) luminal side of the intestinal organoid is not directly accessible in vitro, we investigated the permeability character of the epithelial layer by use of fluorescent tracers.When preparing organoids from different parts of the SI, we obtained the same expression pattern for the Gcg (encoding GLP-1) and Gip m RNA showing that physiology is preserved in vitro (Fig. A region-specific expression pattern of intestinal specific genes in organoids derived from different parts of the intestine including some transporters was recently reported.
Their ease in handling is counterbalanced by special phenotypic features since the cells are almost all tumor-derived.
(b) Diffusion pattern of FITC-Dextran (4 k Da) and FITC-Dextran (40 k Da).
Bottom right: increased light exposure showing lack of diffusion.
These cultures of course cannot simulate the complexity of the intestinal epithelium with multiple cell types and region-specific architecture and hormone expression patterns of all subtypes of EEC seems therefore a better approach to study intestinal functions in vitro but they usually have only poorly differentiated enterocytes not suitable for assessing transport functions.
Moreover, primary IEC are limited by short-term culture and their generation requires rather large number of animals. reported the generation and long-term in vitro cultivation of intestinal organoids (also referred to as “enteroids“.