Structure and Function of Enterocyte in Intrauterine Growth Retarded Pig Neonates

Abstract

The intestine of intrauterine growth retarded (IUGR) neonates showed different morphology compared to neonates born with normal body weight (NBW). The aim of the present study was to investigate the ultrastructure and proteomic profile of the gut epithelium in IUGR pig neonates with special attention to the digestive and absorptive function. Intestine tissue samples were investigated in 7-day-old IUGR and NBW littermate piglets using histometry, immunofluorescence, scanning electron microscopy (SEM), and mass spectrometry analysis. IUGR piglets have shown reduced mucosa and muscularis thickness and an enhanced number of foetal type enterocytes (FTE). SEM studies have shown the lack of the characteristic large-size vacuole in IUGR's enterocytes. Delayed removal of FTE in IUGR neonates was probably due to the inhibited apoptosis in the apical part of villi and increased apoptosis and reduced mitosis in the crypt region. In the expression of proteins in the intestinal mucosa such as hexokinase I, histones, and prelamin A/C, carbamoyl phosphate was reduced in IUGR neonates. Finally, IUGR intestines showed higher expression of HSPA9 and HSPA5 as apoptosis markers. The data indicate modifications of gut mucosa in IUGRs that may result in slower gut mucosa maturation and reduced utilisation of nutrient as compared to NBW pig neonates.

The contribution of vacuolated foetal-type enterocytes in the process of maturation of the small intestine in piglets. Invited review

“…With the use of confocal microscope, it was demonstrated that the expression of lamin A/C was reduced over the entire length of the mucous membrane. The reduced expression of this protein can be the cause or the consequence of the slowed-down mitotic divisions in the intestines of the IUGR piglets (Ferenc et al, 2017). Significant differences were also found in the architecture of the cytoskeleton not only in the foetal enterocytes but also in enterocytes of adults.…”

“…The more intense is the absorption of macromolecules, the larger are the vacuoles. An exception to this are foetal enterocytes in piglets with intrauterine growth retardation (IUGR) syndrome in which the fusion of smaller vesicles into giant vacuoles was halted (Mickiewicz et al, 2012;Ferenc et al, 2017;Figure 3).…”

“…In piglets with the IUGR syndrome it was observed that the small vacuoles do not show the tendency to merge and create giant vacuoles. This may result in a disorder of the intracellular digestion, as the number of lysosomes in cells is limited and, it can be possible that not all small and medium-sized vacuoles contents will be digested (Ferenc et al, 2017; Figure 3). The molecular basis of the observed dysfunction remains obscure, but it may be assumed that what has occurred was a consequence of thrifty phenotype development in the gut mucosa involving the integral membrane proteins that form the ACS or the intracellular proteins that facilitate the fusion of vesicles and smaller vacuoles into increasingly larger structures.…”

“…However, the internal structure of the enterocytes was not further investigated to clarify this phenomenon. It was only the research of Ferenc et al (2017) that showed that in the enterocytes of individuals with IUGR supranuclear spaces do not contain the typical giant vacuoles observed in normal body weight (NBW) piglets. On day 7 of life the supranuclear part of the enterocytes present in the distal section of the jejunum looked like a foamy structure.…”

Postnatal development of skeletal muscle in pigs with intrauterine growth restriction: morphofunctional phenotype and molecular mechanisms

“…Interestingly, the pig provides an adequate animal model to investigate the implications of IUGR, as it shows similarities with humans regarding anatomy, metabolism and rapid postnatal growth rate (Ferenc et al 2017).…”