Intestinal inflammation induced by dextran sodium sulphate causes liver inflammation and lipid metabolism disfunction in laying hens

Abstract

Gut inflammation caused by various factors including microbial infection leads to disorder of absorption of dietary nutrients and decrease in egg production in laying hens. We hypothesized that intestinal inflammation may affect egg production in laying hens through its impact on liver function. Dextran sodium sulphate ( DSS ) is known to induce intestinal inflammation in mammals, but whether it also induces inflammation in laying hens is not known. The goal of this study was to assess whether oral administration of DSS is a useful model of intestinal inflammation in laying hens and to characterize the effects of intestinal inflammation on egg production using this model. White Leghorn hens (350-day old) were administrated with or without 0.9 g of DSS/kg BW in drinking water for 5 D (n = 8, each). All laid eggs were collected, and their whole and eggshell weights were recorded. Blood was collected every day and used for biochemical analysis. Liver and intestinal tissues (duodenum, jejunum, ileum, cecum, cecal-tonsil, and colon) were collected 1 D after the final treatment. These tissue samples were used for histological analysis and PCR analysis. Oral administration of DSS in laying hens caused 1) histological disintegration of the cecal mucosal epithelium and increased monocyte/macrophage infiltration and IL-1β, IL-6, CXCLi2, IL-10, and TGFβ-4 gene expression; 2) decreased egg production; 3) increased leukocyte infiltration and IL-1β, CXCLi2, and IL-10 expression in association with a high frequency of lipopolysaccharide-positive cells in the liver; and 4) decreased expression of genes related to lipid synthesis, lipoprotein uptake, and yolk precursor production. These results suggested that oral administration of DSS is a useful method for inducing intestinal inflammation in laying hens, and intestinal inflammation may reduce egg production by disrupting egg yolk precursor production in association with liver inflammation.

Slight Disruption in Intestinal Environment by Dextran Sodium Sulfate Reduces Egg Yolk Size Through Disfunction of Ovarian Follicle Growth

“…In general, intestinal inflammation causes malnutrition through a decrease in feed intake, digestion, and absorption functions (Peuhkuri et al, 2010 ). Malnutrition caused by feed restriction (60–80% decrease compared with normal feed intake) decreased not only the whole-egg weight, but also egg-shell thickness with a decrease in plasma TG in laying hens in our previous study (Nii et al, 2020 ). In addition, the plasma TG level of molting hens (caused by feed removal) was significantly decreased during the molting phase (Meng et al, 2013 ).…”

“…We previously orally administered 0.9 g DSS/kg BW to laying hens for five consecutive days. This caused histological disintegration of the mucosal epithelial tissue in the cecum, as well as an increased frequency of monocytes/macrophages, and increased expression of IL-1 β, IL-6, CXCLi2, IL-10 , and TGF β -4 with a decrease in feed intake (Nii et al, 2020 ). The previous results suggested that the DSS administration caused heavy intestinal inflammation and damage to the intestinal mucosa.…”

“…VLDLy is formed with 23 units of VLDL-II (known as ApoVLDL-II) and 1 unit of apolipoprotein (apo) B100 (ApoB), and it is produced in the liver (Bujo et al, 1997 ; Walzem et al, 1999 ). We previously reported that rapid severe intestinal inflammation caused by a higher concentration of DSS induced liver tissue inflammation, and the gene expression of lipid synthesis and egg yolk precursor production were significantly decreased in the liver (Nii et al, 2020 ). Therefore, we hypothesized that the decrease in egg yolk size was also caused by dysfunction of the production of the egg yolk precursor in the liver in the present study.…”

“…We previously reported that severe intestinal inflammation caused by DSS may lead to an influx of enteric gram-negative bacteria or LPS from the cecum to the liver through the portal vein (Nii et al, 2020 ). In addition, destruction of the intestinal mucosal barrier led to the invasion of enteric bacteria into the lamina propria, followed by an influx of bacteria and/or endotoxin to other organs through the blood stream (Jahnel et al, 2009 ; Qin et al, 2018 ).…”

“…Recently, the DSS caused intestinal inflammation method had started to be used in chicks for poultry intestinal research (Kuttappan et al, 2015 , 2016 ; Menconi et al, 2015 ; Simon et al, 2016 ). We previously reported that the oral administration of DSS (0.9 g/kg BW) for 5 days caused severe intestinal inflammation and reduced egg laying in laying hens through the disruption of the egg yolk precursor production in association with liver inflammation (Nii et al, 2020 ). This experiment mimics the acute intestinal inflammation caused by pathogenic bacterial infection.…”