The regulation of jejunal induction of the maltase-glucoamylase gene by a high-starch/low-fat diet in mice.

Maltase and glucoamylase are derived from the same mRNA and are responsible for digestion of starch in the small intestine. Their jejunal activities in rodents are induced by a high-starch/low-fat (HS)-diet. However, it is unknown whether jejunal expression of the maltase-glucoamylase (Mgam) gene is enhanced by the HS-diet. In this study, we found that jejunal Mgam mRNA was increased by a HS-diet in mice. We showed that the HS-diet increased acetylation of histones, bindings of a coactivator, Creb binding protein (CREBBP), and the transcriptional factors caudal type homeobox 2 (CDX2) and HNF1 homeobox (HNF1) in the promoter/enhancer and transcriptional regions of Mgam gene. This suggests that the increase in the jejunal activity of maltase and glucoamylase caused by a HS-diet in mice is regulated at the mRNA level through histone acetylation and binding of CREBBP, CDX2 and HNF1 in the promoter/enhancer and transcriptional regions of Mgam gene.