Region-specific ontogeny of α-2,6-sialyltransferase during normal and cortisone-induced maturation in mouse intestine

Abstract

Regional differences in the ontogeny of mouse intestinal α-2,6-sialyltransferase activities (α-2,6-ST) and the influence of cortisone acetate (CA) on this expression were determined. High ST activity and α-2,6-ST mRNA levels were detected in immature small and large intestine, with activity increasing distally from the duodenum. As the mice matured, ST activity (predominantly α-2,6-ST) in the small intestine decreased rapidly to adult levels by the fourth postnatal week. CA precociously accelerated this region-specific ontogenic decline. A similar decline of ST mRNA levels reflected ST activity in the small, but not the large, intestine. Small intestinal sialyl α-2,6-linked glycoconjugates displayed similar developmental and CA induced-precocious declines when probed using Sambucus nigraagglutinin (SNA) lectin. SNA labeling demonstrated age-dependent diminished sialyl α2,6 glycoconjugate expression in goblet cells in the small (but not large) intestine, but no such regional specificity was apparent in microvillus membrane. This suggests differential regulation of sialyl α-2,6 glycoconjugates in absorptive vs. globlet cells. These age-dependent and region-specific differences in sialyl α-2,6 glycoconjugates may be mediated in part by altered α-2,6-ST gene expression regulated by trophic factors such as glucocorticoids.