Gene Expression Is Altered in Piglet Small Intestine by Weaning and Dietary Glutamine Supplementation3

Abstract

Dietary supplementation of glutamine prevents intestinal dysfunction and atrophy in weanling piglets, but the underlying mechanism(s) are largely unknown. This study was conducted to test the hypothesis that weaning or glutamine may modulate expression of genes that are crucial for intestinal metabolism and function. In Expt. 1, we obtained small intestine from 28-d-old pigs weaned at 21 d of age and from age-matched suckling piglets. In Expt. 2, piglets were weaned at 21 d of age and then had free access to diets supplemented with 1% L-glutamine (wt:wt) or isonitrogenous L-alanine (control). At d 28, we collected small intestine for biochemical and morphological measurements and microarray analysis of gene expression using the Operon Porcine Genome Oligo set. Early weaning resulted in increased (52-346%) expression of genes related to oxidative stress and immune activation but decreased (35-77%) expression of genes related to macronutrient metabolism and cell proliferation in the gut. Dietary glutamine supplementation increased intestinal expression (120-124%) of genes that are necessary for cell growth and removal of oxidants, while reducing (34-75%) expression of genes that promote oxidative stress and immune activation. Functionally, the glutamine treatment enhanced intestinal oxidative-defense capacity (indicated by a 29% increase in glutathione concentration), prevented jejunal atrophy, and promoted small intestine growth (+12%) and body weight gain (+19%) in weaned piglets. These findings reveal coordinate alterations of gene expression in response to weaning and aid in providing molecular mechanisms for the beneficial effect of dietary glutamine supplementation to improve nutrition status in young mammals.

A carvacrol–thymol blend decreased intestinal oxidative stress and influenced selected microbes without changing the messenger RNA levels of tight junction proteins in jejunal mucosa of weaning piglets

“…Recent studies have indicated that early weaning may induce intestinal oxidative stress, which contributes to intestinal dysfunction (Wang et al, 2008;Zhu et al, 2012). In this study, we have investigated whether supplementing a carvacrol-thymol blend in the diet lowered early All results are presented as mean ± SEM (n = 6).…”

“…Numerous studies have shown that dysfunction of the intestine, which has important immunological, metabolic and barrier functions, has been demonstrated to play a crucial role in weaning-induced growth check (Wijtten et al, 2011;Campbell et al, 2013). Recent studies have indicated that decreased antioxidant activity and increased production of reactive oxygen species (ROS) is involved in weaning-induced intestinal dysfunction, resulting in intestinal oxidative stress (Wang et al, 2008;Degroote et al, 2012;Zhu et al, 2012). The intestinal oxidative stress is frequently associated with inflammation (Rada et al, 2011;Padgett et al, 2013).…”

Response to weaning and dietary l-glutamine supplementation: metabolomic analysis in piglets by gas chromatography/mass spectrometry

“…The contents (g/kg, unless otherwise specified, as-fed basis) were as follows: dry matter, 887.4; crude protein, 214.8; crude ash, 52.2; total calcium, 9.1; total phosphorus, 6.1; total energy (kJ/g), 14.12;arginine,11.68;alanine,9.68;aspartate+asparagine,18.25;cysteine,3.10;glutamate+ Gln,39.66;glycine,8.52;histidine,4.86;isoleucine,7.97;leucine,17.14;lysine,12.03;methionine,3.41;phenylalanine,9.10;proline,8.91;serine,9.05;threonine,8.54;tyrosine,5.11;and valine,8.24. The amount of supplemental Gln and the reason for the choice of alanine as the isonitrogenous control were based on the researches of Wu et al (1996) and Wang et al (2008).…”

“…Weaning is a critical but also inevitable stage in the postnatal growth and metabolism of mammals (Henning, 1981;Wang et al, 2008). Abrupt weaning is commonly associated with a period of low feed intake, decreased digestive capability, and increased occurrence of enteric diseases and diarrhea (Bruininx et al, 2001;Wijtten et al, 2011), generally leading to a net catabolic state (le Dividich and Sève, 2000).…”

Functional amino acids in nutrition and health

“…Moreover, leucine activates the mammalian target of rapamycin to stimulate protein synthesis and inhibit intracellular proteolysis (Dillon 2012;Li et al 2011b), whereas methionine is the major donor of the methyl group to affect DNA and protein methylation in cells (Wang et al 2012). Notably, nutritional studies have shown that dietary supplementation with several AA (e.g., arginine, glutamine, glutamate, leucine, and proline) modulates gene expression and enhances growth of the small intestine and skeletal muscle (Geng et al 2011;Jobgen et al 2009;Wang et al 2008;Wu et al 2011a, b; Regulation of acid-base balance (e.g., renal ammoniagenesis from glutamine)…”