Developmental changes in polyamines and autophagic marker levels in normal and growth-restricted fetal pigs1,2

Abstract

Polyamines are essential for embryonic and fetal survival, growth, and development. Additionally, polyamines may induce autophagy in mammalian cells. However, little is known about the availability of polyamines or autophagy in the porcine conceptus with intrauterine growth restriction (IUGR). The present study was performed to evaluate the developmental changes of polyamine concentrations in IUGR and normal porcine fetuses as well as autophagic marker levels in the fetal intestinal mucosa during the second half of gestation when most fetal growth occurs. Allantoic fluid (ALF), amniotic fluid (AMF), umbilical vein, and the small-intestinal mucosa were obtained from both IUGR and normal fetal pigs at d 60, 90, and 110 of gestation. Concentrations of polyamines in fetal fluids as well as protein abundances of microtubule-associated protein light chain 3B (LC3B), an autophagic marker, in the fetal small-intestinal mucosa were determined. Concentrations of polyamines varied greatly in different fetal compartments and changed substantially with advancing gestation. Concentrations of polyamines in IUGR fetal fluids and the small-intestinal mucosa were markedly different from those in their normal counterparts at d 60 and 90 of gestation, whereas most of the differences were not detected by late (d 110) gestation. Specifically, polyamine levels were lower in the umbilical vein plasma but higher in ALF and AMF from IUGR fetuses. Furthermore, enhanced levels of an autophagic marker were observed in the small-intestinal mucosa of IUGR fetuses throughout mid and late gestation in association with abnormal spermidine levels in fetal plasma. These findings support the notion that enhanced autophagy may be an important survival mechanism in IUGR fetuses. Collectively, our findings provide a new framework for future studies to define the roles for polyamines in the prevention and treatment of IUGR in both human medicine and animal production.

Zinc Oxide Nanoparticle Improves the Intestinal Function of Intrauterine Growth Retardation Finishing Pigs via Regulating Intestinal Morphology, Inflammation, Antioxidant Status and Autophagy

“…These results suggested that IUGR enhanced the jejunal mucosal autophagy of pigs. Similarly, previous studies have shown that IUGR increases the number of abnormal mitochondrial and autophagy protein expression in the intestinal mucosa of piglets ( 20 , 70 ). However, dietary supplementation with Nano-ZnO reduced the number of swollen mitochondria and autolysosomes, improved the shape and structure of mitochondria and down-regulated the protein expression of P62 and the ratio of LC3B to LC3A in jejunal mucosa of IUGR finishing pigs, suggesting that Nano-ZnO could reduce IUGR-induced autophagy in jejunal mucosa.…”

Effects of dietary arginine supplementation in pregnant mares on maternal metabolism, placental structure and function and foal growth

“…At foaling, PA mares had increased L-ornithine plasma concentration compared to PC mares without changes in foal plasma concentrations. L-ornithine is a precursor of putrescine, a polyamine precursor of other polyamines such as spermine and spermidine 19 , that are involved in growth and development and decreased in intra uterine growth retarded foetuses 40 .…”

Spermidine Alleviates Intrauterine Hypoxia-Induced Offspring Newborn Myocardial Mitochondrial Damage in Rats by Inhibiting Oxidative Stress and Regulating Mitochondrial Quality Control

“…It is well-documented that polyamines involve in placental angiogenesis and embryogenesis as well as embryonic and fetal growth and development ( 47 ). Zhu et al reported that polyamine levels were lower in the umbilical vein plasma from intrauterine growth restriction (IUGR) porcine fetuses, and supplementary SPD to the mother may prevent IUGR ( 48 ). Spermidine is a compound with reasonable safety and lower toxicity ( 49 ).…”