Sonic hedgehog (Shh) protein is a major regulator of embryonic gut development but its postnatal role is poorly understood. In August Gastroenterology, Gijs Van Den Brink and colleagues from the Academic Medical Center, Amsterdam show that in adult tissues Shh is a negative regulator of gastric gland cell proliferation and controls the expression of gut epithelial differentiation.

Van Den Brink et al. investigated the expression of Shh and putative transcriptional targets in gastric tissues from humans and mice. They found that Shh is expressed in epithelium of the adult human and murine stomach and that inhibition of Shh in cyclopamine-treated mice was associated with enhanced gastric epithelial proliferation but left pit cells unaffected. In addition, inhibition of Shh decreased expression of 3 putative Shh target genes: HNF3β, Islet-1 and BMP4 (Gastroenterology 2001, 121:317-328).

Hedgehog signaling is thus not only important during organ genesis but remains essential...