For histology, tissue samples were stained with hematoxylin and eosin. To determine Paneth cell-specific expression of lysozyme, trypsin, and HD5, immunohistochemistry was performed as described ...

During homeostasis, the ISC niche exists in the crypt together with differentiated cells (e.g., lysozyme producing Paneth cells in the small intestine) and stromal cells at the underlying mesenchyme.

The study shows that during ageing, Paneth cells begin to express a secreted Wnt-inhibitor called Notum. Notum enzymatically inactivates Wnt-ligands in the stem cell niche, decreasing regenerative ...