The Development of Spasmolytic Polypeptide/TFF2-Expressing Metaplasia (SPEM) During Gastric Repair Is Absent in the Aged Stomach.

Background & Aims: During aging, physiological changes in the stomach result in more tenuous gastric tissue that is less capable of repairing injury, leading to increased susceptibility to chronic ulceration. Spasmolytic polypeptide/trefoil factor 2-expressing metaplasia (SPEM) is known to emerge after parietal cell loss and during infection, however, its role in gastric ulcer repair is unknown. Therefore, we sought to investigate if SPEM plays a role in epithelial regeneration.

Characterization of stem/progenitor cell cycle using murine circumvallate papilla taste bud organoid.

Leucine-rich repeat-containing G-protein coupled receptor 5-expressing (Lgr5(+)) cells have been identified as stem/progenitor cells in the circumvallate papillae, and single cultured Lgr5(+) cells give rise to taste cells. Here we use circumvallate papilla tissue to establish a three-dimensional culture system (taste bud organoids) that develops phenotypic characteristics similar to native tissue, including a multilayered epithelium containing stem/progenitor in the outer layers and taste cells in the inner layers. Furthermore, characterization of the cell cycle of the taste bud progenitor niche reveals striking dynamics of taste bud development and regeneration.

Establishment of Gastrointestinal Epithelial Organoids.

The intestinal epithelium constitutes a system of constant and rapid renewal triggered by proliferation of intestinal stem cells (ISCs), and is an ideal system for studying cell proliferation, migration, and differentiation. Primary cell cultures have proven to be promising for unraveling the mechanisms involved in epithelium homeostasis. In 2009, Sato et al.