Figure 5.

Claudin 2 protein levels are increased in the small intestine of stressed pups at 48 hours, claudin 2 gene expression is up-regulated at 6 hours, and claudin 4 and 7 gene expression is down-regulated at 24 hours, compared with DF controls. A: Presence of occludin and claudins 2, 4, and 7 in the small intestine of NEC stressed mouse pups versus DF controls at 12, 24, and 48 hours was analyzed by Western blotting. Membranes were then stripped and immunoblotted for β-actin, and the results were quantified. Similar results were obtained in two independent experiments. Nonadjacent lanes from the same blot are separated by a fine space. B: The gene expression profile of claudins 2, 4, and 7 relative to K8 was obtained by qPCR in DF versus stressed pups at 6, 12, 24, and 48 hours. Data are expressed as means ± SEM. n = 4 samples per group (A) or 3 to 8 samples per group, run in duplicate (B). ∗P < 0.05. Cl, claudin.