Figure 5.
The sorting of sucrase-isomaltase (SI) and dipeptidyl peptidase-4 (DPPIV) is impaired in dextran sulfate sodium (DSS) treated Caco-2 cells. (A) Trafficking of SI to brush border membrane (BBM). (B) Trafficking of DPPIV to BBM. Caco-2 cells were treated or not treated with DSS. The cellular homogenates (H) were separated into intracellular and basolateral membranes (P1) or BBM (P2) using CaCl2. The fractions were subjected to Western blotting using anti-SI (A) or anti-DPPIV (B) antibodies. S represents soluble and vesicular (endosomal) proteins. Upon DSS treatment, a substantial decrease in the expression levels of SI and DPPIV is observed in BBM (P2 fractions). (Student’s t-test, * p < 0.05, ** p < 0.01, SEM, n = 3).