Postnatal regulation of MAMDC 4 in the porcine intestinal epithelium is influenced by bacterial colonization

• Published in: Physiological reports 2016-11, Vol.4 (21)
• Main Authors: Pasternak, Alex J., Hamonic, Glenn M., Van Kessel, Andrew, Wilson, Heather L.
• Format: Article
• Language: English
• Subjects: Bacteria; Birth; Colonization; Developmental stages; Epithelial cells; Epithelium; Fetuses; Glycoproteins; Health care; Hogs; Ileum; Intestinal microflora; Jejunum; Localization; Microbiota; Permeability; Physiology; Proteins; Small intestine; Transcription; Veterinary medicine
• ISSN: 2051-817X
• DOI: 10.14814/phy2.13018

The MAM domain‐containing 4 ( MAMDC 4) protein is associated with the unique endocytotic mechanism observed in the intestine of mammals during the immediate postnatal period. Transcriptional expression of MAMDC 4 was substantially upregulated at birth in both the piglet jejunum and ileum and its expression decreases after birth. The protein was found localized specifically to the apical region of the luminal epithelium, however, MAMDC 4 protein expression was lost at day 10 and 15 in the jejunum and ileum, respectively, and was not associated with “fetal” enterocyte replacement. Although spatial variation in the subcellular localization of Claudin 1 ( CLDN 1) was noted at day 3, the loss of MAMDC 4 at later stages of development did not appear to have any effect on the tight junction structure. Germ‐free ( GF ) piglets and piglets whose gastrointestinal flora consists exclusively of Escherichia coli ( EC ) or Lactobacillus fermentum ( LF ) maintained MAMDC 4 protein expression to 14 days of age in distal regions of the small intestine whereas those with conventionalized intestinal flora ( CV ) showed no MAMDC 4 protein at this age. MAMDC 4 protein expression was most pronounced in the LF and GF colonized piglets which showed staining in the epithelial cells at 75% and 95% of the length of the small intestine, respectively, which matched that of the newborn. In contrast, EC animals showed only a low abundance at these regions as well as a discontinuous staining pattern. Collectively these results suggest that maturation of MAMDC 4 expression in the porcine epithelium occurs more rapidly than what is reported in previously studied rodent species. Furthermore, intestinal bacterial colonization is a major regulator of MAMDC 4 in a manner specific to bacterial species and independent of enterocyte turnover.