PAK1 expression was more pronounced within SB villi in comparison to the surface of the LB epithelium, which may provide a physiological advantage in modulating cytoskeletal rearrangements required for enterocyte migration along the villus axis.
In addition, enterocyte migration was accelerated in the T4-injected rats and reduced in the hypothyroid group compared with controls.
To assess the molecular mechanisms underlying the regulation of lactase ontogeny by thyroxine (T4), we performed an in vivo study of lactase catalytic activity, synthesis, subunit structure, degradation, and enterocyte migration rates in propylthiouracil-induced hypothyroid rat pups, hypothyroid pups injected with T4, and normally weaned rats.
These results suggest that α2 integrin participates in Sb-enhanced enterocyte migration.
In this study, we determined whether Sb could accelerate enterocyte migration.
Altogether these data indicate that the Sb-induced enterocyte migration depends on α2β1 integrin.
Enterocyte migration requires dynamic interactions between ECM molecules, such as laminin isoforms and collagens, and their cell surface receptors [27].
Enterocyte migration was determined by measuring the distance from the bottom of the crypt to the foremost labeled enterocyte and expressing the distance as a percentage of the total villus height.
To confirm the role of α2β1integrin in Sb-enhanced enterocyte migration, HCT-8/E11 cells, which express the integrins α2β1, α3β1, α5β1, αvβ5, and α6β4 (unpublished data), were incubated with function blocking anti-integrin mAbs during cell migration.
To evaluate whether Sb supernatant regulates enterocyte migration in vivo, C57BL6J mice were force-fed with PBS solution with or without 1 mg/ml Sb, daily, for 1 week.
