Effect of GLP-2 on mucosal morphology and SGLT1 expression in tissue-engineered neointestine

Using tissue-engineering techniques, we have developed a neointestine that regenerates the structural and dynamic features of native small intestine. In this study, we tested neointestinal responsiveness to glucagon-like peptide 2 (GLP-2). Neointestinal cysts were engineered by seeding biodegradable polymers with neonatal rat intestinal organoid units. The cysts were matured and anastomosed to the native jejunum of syngeneic adult recipients. Animals were treated with GLP-2 [Gly(2)] (twice daily, 1 mug/g body wt) or vehicle alone (control) for 10 days. Rats were then killed, and tissues were harvested for analysis. Na+-glucose cotransporter (SGLT1) mRNA expression was assessed with Northern blotting and in situ hybridization. SGLT1 protein was localized by using immunofluorescence. GLP-2 administration resulted in 1.8- and 1.7-fold increases (P<0.05) in neointestinal villus height and crypt depth, respectively. GLP-2 administration also resulted in a 2.4-fold increase (P<0.01) in neomucosal SGLT1 mRNA expression. SGLT1 mRNA expression was localized to enterocytes throughout the villi, and SGLT1 protein was localized to the brush border of enterocytes along the entire length of villi from the neointestine of GLP-2-treated animals. The response of tissue-engineered neointestine to exogenous GLP-2 includes mucosal growth and enhanced SGLT1 expression. Therefore, tissue-engineering principles may help in dissecting the regulatory mechanisms mediating complex processes in the intestinal epithelium.