Table 1.
Overview of Techniques Used to Evaluate Goblet Cell and Mucus Function
| Techniques | Used on | Compatible organoid method | Goblet cell properties/mucus functions | Reference |
|---|---|---|---|---|
| Immunofluorescent staining for mucus composition | In vitro ALI monolayer; in vivo mouse colon staining | 2D monolayer; 3D organoids | Expression of mucus protein components MUC2, MUC5AC, TFF3, AGR2, RELMβ, FCGBP, CLCA1, and ZG16 | 75,90 |
| Isotope label of mucin | In vivo and ex vivo mouse colon and mucus | 2D monolayer | Mucin synthesis and production after 3H-glucosamine injection | 91 |
| GalNAz label of mucin (Click-iT) | In vivo mouse small intestine | 2D monolayer; 3D organoids | Mucin synthesis and production by labeling mucin glycoproteins | 92, 93, 94 |
| Secretagogue stimulation | Ex vivo mouse colon | 2D monolayer; 3D organoids | Mucin secretion and goblet cell maturity stimulated by acetylcholine or analogs | 95,96 |
| Activated charcoal and micropipettor | Ex vivo mouse colon | 2D monolayer | Mucus thickness measured by adding charcoal particles on mucus apical surface | 75,95, 96, 97 |
| Fluorescent beads | In vitro monolayer; ex vivo mouse intestine | 2D monolayer | Mucus thickness measured by distance of beads to epithelium | 90,94,98 |
| Penetrable beads | In vitro monolayer; ex vivo mouse intestine | 2D monolayer | Mucus permeability to bacteria-sized fluorescent beads | 75,95,96 |
| LC-MSMS | In vivo mouse colon mucus | 2D monolayer | Proteomic analysis of the mucus layer | 75,94,98 |
AGR2, anterior gradient 2; CLCA1, chloride channel regulator, calcium-activated-1; FCGBP, IgGFc-binding protein; GalNAz, N-azidoacetylgalactosamine; LC-MSMS, liquid chromatography with tandem mass spectrometry; MUC2, mucin 2; MUC5AC, mucin5AC; RELMβ, resistin-like molecule β; TFF3, Trefoil Factor 3; ZG16, zymogen granule membrane protein 16.