NF-kappaB signaling in intestinal epithelial regeneration
The intestinal epithelium is the fastest regenerating tissue in the adult mammal. This is guaranteed by intestinal stem cells (CBC’s) that reside in the so-called crypts in the bottom of the villi. These CBC’s are able to give rise to all cell components of the intestinal epithelium. Although the function of various signaling molecules in intestinal epithelial regeneration, such as WNT and Notch, has been well studied, the exact signaling cascades leading to stem cell activation and differentiation remain obscure. Aberrant NF-κB activity has been previously associated with colon carcinoma. However, a physiological role for NF-κB in intestinal homeostasis has not been described thus far. We observed strong NF-κB activity in particular stem cells and Paneth cells in the crypts of the small intestine. In line with this, recent results from or laboratory evidenced an essential role of NF-κB in Paneth and goblet cell differentiation. This is currently analyzed in more detail.
Fig. 4 NF-κB activity in crypts of small intestine (in red).
Karsten Krieger, Ruth Schmidt-Ullrich
Sarah Millar (Dept. of Dermatology and Cell & Developmental Biology, University of Pennsylvania, Philadelphia), Christian Klotz, Anton Aebischer (Robert-Koch-Institut, Berlin) Julian Heuberger (Laboratory of Walter Birchmeier, MDC)