Lipopolysaccharide induces acute bursal atrophy in broiler chicks by activating TLR4-MAPK-NF-κB/AP-1 signaling

Abstract

We investigated the mechanisms that induce atrophy of the chicken bursa of Fabricius (BF) upon lipopolysaccharide (LPS) treatment in young chicks. LPS treatment resulted in ∼36% decrease in bursal weight within 36 h (P < 0.01). Histological analysis showed infiltration of eosinophilic heterophils and nucleated oval shaped RBCs in or near blood vessels of the BF from LPS-treated chicks. Scanning electron micrographs showed severe erosion and breaks in the mucosal membrane at 12 h and complete exuviation of bursal mucosal epithelial cells at 36 h. We observed decreased cell proliferation (low PCNA positivity) and increased apoptosis (high TUNEL and ssDNA positivity) in the BF 12-72 h after LPS treatment. RNA-seq analysis of the BF transcriptome showed 736 differentially expressed genes with most expression changes (637/736) 12 h after LPS treatment. KEGG pathway analysis identified TLR4-MAPK-NF-κB/AP-1 as the key signaling pathway affected in response to LPS stimulation. These findings indicate LPS activates the TLR4-MAPK-NF-κB/AP-1 signaling pathway that mediates acute atrophy of the chicken bursa of Fabricius by inducing inflammation and apoptosis.

Influence of autolyzed whole yeast and yeast components on broiler chickens challenged with salmonella lipopolysaccharide

“…(2000) and Ansari et al. (2017), that also reported that LPS challenge markedly reduced bursal weight in LPS-challenged broiler chickens compared to the control group. At the end of the experiment (day 35), there was no observed difference in the relative weight of the spleen, bursa, and liver between the different treatment groups.…”

RNA-Seq-Based Gene Expression Pattern and Morphological Alterations in Chick Thymus during Postnatal Development

“…GO functional classification on DEGs for each pair was conducted following the previously described method [25]. All GO terms are grouped into three ontologies: biological process, cellular component, and molecular function.…”

“…Following construction of strand-specific libraries, sequencing was done on an Illumina HiSeq 4000 platform by BGI Genomics Co. Ltd. (Shenzhen, China). Differentially expressed genes (DEGs) were screened using the NOISeq method with absolute fold change ≥ 2 and divergent probability ≥ 0.8 [24, 25]. The read length was 50 bp.…”

Screening of differentially expressed immune-related genes from spleen of broilers fed with probiotic Bacillus cereus PAS38 based on suppression subtractive hybridization

“…Monson et al [62] studied the effect of aflatoxin B1 and probiotics on turkey spleen transcriptome, and found that the expression level of DOCK10 had no significant different in the group of aflatoxin B1 and the group of probiotics compared with the control group, but it was significantly up-regulated in the group of aflatoxin B1+probiotics compared with the control group. Ansari et al [63] investigated the mechanisms that induce atrophy of the chicken bursa of fabricius upon lipopolysaccharide (LPS) treatment in young chicks, found that LPS treatment resulted in a significant decrease in the weight of bursa of fabricius, and the decrease of cell proliferation; at the same time, the DOCK10 was significantly up-regulated. This suggests that DOCK10 , as a proinflammatory factor, its high expression can induce abnormal apoptosis.…”