Polysaccharide of Atractylodes macrocephala Koidz alleviate lipopolysaccharide-induced liver injury in goslings via the p53 and FOXO pathways

Abstract

Lipopolysaccharide (LPS) can affect the immune system of geese by inducing liver injury. The polysaccharide of Atractylodes macrocephala Koidz (PAMK) have obvious immune-enhancing effects. Accordingly, this experiment investigated the effect of PAMK on LPS-induced liver injury in goslings. Two hundred 1-day-old goslings were randomly divided into the control group, LPS group, PAMK group, and PAMK+ LPS group, and the PAMK and PAMK+ LPS groups were fed the basal diet with 400 mg/kg PAMK, while the control and LPS groups were fed the basal diet. On D 21, 23, and 25 of the formal trial, the goslings in the LPS and PAMK+LPS groups were injected intraperitoneally with 2 mg/kg LPS, and goslings in the control and PAMK groups were injected intraperitoneally with the same amount of saline. Livers were collected on D 25. HE-stained sections showed that PAMK could effectively alleviate the LPS-induced indistinct hepatic cord structure, loss of cytoplasmic contents of hepatocytes, and dilatation of hepatic sinusoids. The biochemical parameters of liver tissues showed that PAMK could alleviate the LPS-induced upregulation of alanine aminotransferase and aspartate aminotransferase. To further investigate the mechanism of the mitigating effect of PAMK on LPS-induced injury, livers from the LPS and PAMK+LPS groups were selected for transcriptome sequencing. The sequencing results showed that there were 406 differentially expressed genes (DEGs) in the livers of LPS and PAMK+LPS goslings, of which 242 upregulated and 164 downregulated. The Kyoto Encyclopedia of Genes and Genome (KEGG) analysis showed that DEGs were significantly enriched in immune signal transduction, cell cycle, and cell metabolism. Besides, protein‒protein interaction analysis showed that 129 DEGs were associated with each other, including 7 DEGs enriched in the p53 and FOXO signaling pathway. In conclusion, PAMK may alleviate LPS-induced liver injury in gosling through the p53 and FOXO signaling pathway. These results provide a basis for further development of PAMK as an immunomodulator.

Keywords: gene expression; gosling; lipopolysaccharide; liver; polysaccharide of Atractylodes macrocephala Koidz.

Figure 1

HE staining results of gosling livers (400 ×). The black arrow points to the central vein, and the red arrow points to the hepatic sinusoids.

Figure 2

Effect of PAMK on LPS-induced ALT and AST in the livers of goslings. Data are expressed as the mean ± standard error (SEM). The data columns labeled with different lowercase letters indicate significant differences (P < 0.05), as in the following figure.

Figure 3

Expression of mRNA in the livers of goslings. (A) Length distribution of mRNAs. (B) Exon number distribution of mRNAs. (C) Description results of the regional distribution of mRNAs.

Figure 4

DEGs in the livers of the LPS and PAMK + LPS groups of goslings. (A)Volcano map of LPS vs. PAMK + LPS DEGs. (B) Heatmap of LPS vs. PAMK + LPS DEGs.

Figure 5

GO and KEGG pathway enrichment analyses of DEGs in gosling liver. (A) GO enrichment histogram of LPS vs. PAMK + LPS DEGs. (B) KEGG enrichment bubble plot of LPS vs. PAMK + LPS DEGs.

Figure 6

Interaction map of the differentially expressed protein‒protein network. (A) PPI map of all DEGs. (B) PPI map of DEGs in 5 related signaling pathways. (C) Cross plot of all DEG in PPIs and DEGs in 5 related signaling pathways. The size of the circle shows the strength of the data support, with red representing upregulated genes and blue representing downregulated genes.

Figure 7

The results of qRT‒PCR and RNA-seq for 7 DEGs from two comparison groups.

Figure 8

Diagram of the p53 and FOXO signaling pathways.