l-Glutamine and l-arginine protect against enterotoxigenic Escherichia coli infection via intestinal innate immunity in mice

Abstract

Dietary glutamine (Gln) or arginine (Arg) supplementation is beneficial for intestinal health; however, whether Gln or Arg may confer protection against Enterotoxigenic Escherichia coli (ETEC) infection is not known. To address this, we used an ETEC-infected murine model to investigate the protective effects of Gln and Arg. Experimentally, we pre-treated mice with designed diet of Gln or Arg supplementation prior to the oral ETEC infection and then assessed mouse mortality and intestinal bacterial burden. We also determined the markers of intestinal innate immunity in treated mice, including secretory IgA response (SIgA), mucins from goblet cells, as well as antimicrobial peptides from Paneth cells. ETEC colonized in mouse small intestine, including duodenum, jejunum, and ileum, and inhibited the mRNA expression of intestinal immune factors, such as polymeric immunoglobulin receptor (pIgR), cryptdin-related sequence 1C (CRS1C), and Reg3γ. We found that dietary Gln or Arg supplementation decreased bacterial colonization and promoted the activation of innate immunity (e.g., the mRNA expression of pIgR, CRS1C, and Reg3γ) in the intestine of ETEC-infected mice. Our results suggest that dietary arginine or glutamine supplementation may inhibit intestinal ETEC infection through intestinal innate immunity.

Serum Metabolomics Profiling to Identify Biomarkers for Unstable Angina

“…The energy metabolism of myocardium cells was disturbed in UA patients and these cells have to find alternative substrates to provide energy [25, 26]. Glutamine, a critical resource for gluconeogenesis, is classified as a form of glucogenic amino acid, and glutamine itself is a critical component of the TCA cycle; moreover, it performs a crucial function in numerous metabolic pathways, in particular regarding the maintenance of amino acid homeostasis [27]. Some researches drew on metabolomics profiling for the purpose of comparing cardiac extraction and plasma substrates, and the results indicated that CHD experienced a lower level of glutamate or glutamine [28].…”

Review: The roles and functions of glutamine on intestinal health and performance of weaning pigs

“…Further work is necessary to determine if and how glutamine changes these signal pathways to promote Lgr5 stem cell development. Some studies indicate that supplemental glutamine had no effect on lysozyme and angiogenin expressions that are Paneth cell markers (Liu et al, 2017;Chen et al, 2018a). For example, glutamine at a dosage of 2% did not promote mRNA expression in other Paneth cell-associated factors such as α-defensins (cryptdin-1, -4 and -5), lysozyme C and angiogenin 4 in the ileum of mouse models (Liu et al, 2017).…”

“…Some studies indicate that supplemental glutamine had no effect on lysozyme and angiogenin expressions that are Paneth cell markers (Liu et al, 2017;Chen et al, 2018a). For example, glutamine at a dosage of 2% did not promote mRNA expression in other Paneth cell-associated factors such as α-defensins (cryptdin-1, -4 and -5), lysozyme C and angiogenin 4 in the ileum of mouse models (Liu et al, 2017). Glutamine at a dosage of 10 mg/ml fed to weaning mice did not affect the number of absorptive enterocytes, Paneth cells, goblet cells, enteroendocrine cells or the gene expression of these cell markers (Chen et al, 2018a).…”

Peer Review #1 of "Effects of xylo-oligosaccharide and flavomycin on the immune function of broiler chickens (v0.1)"

“…The intestinal immune system has a complicated relationship with intestinal microorganisms (Chow et al 2010;Liu et al 2017); intestinal commensal flora could effectively inhibit the intestinal inflammatory response and promote immune tolerance through the Toll-like receptor pathway (Round et al 2011). Pourabedin et al (Pourabedin et al 2015) and Maesschalck et al (Maesschalck et al 2015) determined the effect of XOS and virginiamycin on the microbes in the intestine of broiler chickens by 16S rRNA pyrophosphate sequencing, and the results showed that the addition of XOS and virginiamycin to diets could regulate the relative abundance of intestinal flora.…”