Characteristic Changes in Cell Surface Glycosylation Accompany Intestinal Epithelial

Changes in cell surface glycosylation occur during the development and differentiation of cells and have been widely correlated with the progression of several dis-eases. Because of their structural diversity and sensitivity to intra- and extracellular conditions, glycans are an in-dispensable tool for analyzing cellular transformations. Glycans present on the surface of intestinal epithelial cells (IEC) mediate interactions with billions of native microor-ganisms, which continuously populate the mammalian gut. A distinct feature of IECs is that they differentiate as they migrate upwards from the crypt base to the villus tip. In this study, nano-LC/ESI QTOF MS profiling was used to characterize the changes in glycosylation that correspond to Caco-2 cell differentiation. As Caco-2 cells differentiate to form a brush border membrane, a decrease in high mannose type glycans and a concurrent increase in fuco-sylated and sialylated complex/hybrid type glycans were observed. At day 21, when cells appear to be completely differentiated, remodeling of the cell surface glycome ceases. Differential expression of glycans during IEC maturation appears to play a key functional role in reg-ulating the membrane-associated hydrolases and con-tributes to the mucosal surface innate defense mecha-nisms. Developing methodologies to rapidly identify changes in IEC surface glycans may lead to a rapid screen-ing approach for a variety of disease states affecting the G