Mechanism of iron on the intestinal epithelium development in suckling piglets.

This study aimed to investigate the mechanism of iron on intestinal epithelium development of suckling piglets. Compared with newborn piglets, 7-day-old and 21-day-old piglets showed changes in the morphology of the jejunum, increased proliferation, differentiated epithelial cells, and expanded enteroids. Intestinal epithelium maturation markers and iron metabolism genes were significantly changed. These results suggest that lactation is a critical stage in intestinal epithelial development, accompanied by changes in iron metabolism. In addition, deferoxamine (DFO) treatment inhibited the activity of intestinal organoids at passage 4 (P4) of 0-day-old piglets, but no significant difference was observed in epithelial maturation markers at passage 1 (P1) and P4, and only argininosuccinate synthetase 1 (Ass1) and β-galactosidase (Gleb) were up-regulated at passage 7 (P7). These results in vitro show that iron deficiency may not directly affect intestinal epithelium development through intestinal stem cells (ISCs). The iron supplementation significantly down-regulated the mRNA expression of interleukin-22 receptor subunit alpha-2 (IL-22RA2) in the jejunum of piglets. Furthermore, the mRNA expression of IL-22 in 7-day-old piglets was significantly higher than that in 0-day-old piglets. Adult epithelial markers were significantly up-regulated in organoids treated with recombinant murine cytokine IL-22. Thus, IL-22 may play a key role in iron-affecting intestinal epithelium development.