Molecular characterization and gene expression analysis of the pro-inflammatory cytokines IL-1β and IL-8 in the South American fish Piaractus mesopotamicus challenged with Aeromonas dhakensis

Abstract

In the present study, the complete characterization of cDNA and genomic sequences of IL-1b and IL-8, as well as the expression profile of these genes in the South American fish pacu (Piaractus mesopotamicus) is provided. The full-length pmIL-1b cDNA was composed of 1208 nucleotides that would produce a precursor peptide with 273 amino acid residues. A putative caspase-1 cleavage site, similar to what is found in mammalian IL-1b, was identified producing a mature peptide with a theoretical molecular weight of 17.21 kDa. The pmIL-8 cDNA sequence consisted of 1019 nucleotides which encoded a 95-amino acid protein with a theoretical molecular weight of 10.43 kDa that showed all typical CXC chemokine features, including a 20-residue signal peptide and four conserved cysteine residues. Constitutive mRNA expression was detected for both genes in the liver, head kidney, gill, intestine, skin and spleen. After a bacterial challenge, up-regulation was detected for both pmIL-1b and pmIL-8 in the spleen and head kidney at 12 h post-infection. At 24 h post-infection there was a decrease in the expression of both genes, with pmIL-8 showing a significant down-regulation in the liver and head kidney when compared to the control groups.

Comparative Transcriptomic Analysis Reveals the Regulated Expression Profiles in Oreochromis niloticus in Response to Coinfection of Streptococcus agalactiae and Streptococcus iniae

“…In this study, the expression of IL-1β was upregulated significantly within 24 h in the intestine and then decreased between 24 h and 7 days. Similar to our results, the expression of IL-1β significantly increased at 12 h and then decreased between 12 and 24 h following a bacterial infection in Piaractus mesopotamicus ( Carriero et al, 2020 ). Our results suggested that after streptococcal infection, B cells and other immune cells were activated by IL-1β to protect the organisms from pathogenic stress, exerting a role in modulating the cellular immune response.…”

A. caviae infection triggers IL-1β secretion through activating NLRP3 inflammasome mediated by NF-κB signaling pathway partly in a TLR2 dependent manner

“…A. hydrophila caused mitochondrial dysfunction, produced mtROS release, translocated mtDNA to cytoplasm, activated caspase-1/IL-1β, and induced IL-1β production [ 16 ]. IL-1β also functioned against A. dhakensis infection in the spleen and head kidney of Piaractus mesopotamicus at the initial stage [ 10 ], as well as A. sobria infection in primary mouse macrophages via activating NLRP3 inflammasome [ 8 ]. In our study, mice in vivo infection assays demonstrated that A. caviae infection-induced IL-1β release in murine serum.…”

“…Studies so far revealed that the infection with A. hydrophila [ 6 ], A. veronii [ 7 ], A. sobria [ 8 ], A. salmonicida [ 9 ] and A. dhakensis [ 10 ] would induce a series of inflammatory response with elevated IL-1β, TNF-α, IL-6, IL-8 and so on. IL-1β was a potent cytokine that functioned in host-response and the resistance to pathogens [ 11 ].…”

“…Macrophages played a vital role in the resistance to the pathogenic infection [ 15 ]. A. dhakensis infection enhanced pro-IL-1β transcription in the spleen as well as head kidney of South American fish Piaractus mesopotamicus [ 10 ]. A. hydrophila induced IL-1β release and disturbed head kidney macrophages mitochondrial dysfunction and apoptosis [ 16 ].…”

Effects of Low- and High-Level Gossypol and Sodium Butyrate Supplementation Under High-Level Gossypol Condition on Growth Performance and Intestinal Health of Hybrid Grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂)

“…Fish intestinal inflammatory cytokines are closely related to intestinal health, and inflammatory cytokines play different roles in intestinal inflammation (Tian et al, 2017). Inflammatory factors are usually classified into two types: proinflammatory factors, such as tnfα, il1β, il8, and ifnγ (Li et al, 2018b;Carriero et al, 2020), whose upregulation further exacerbates inflammation, and antiinflammatory factors, such as tgfβ1 and hepcidin (Li et al, 2017;Yan et al, 2019), whose upregulation enhances the intestinal anti-inflammatory capacity. In addition, hepcidin and il6, which often show high expression in intestinal inflammation, have different roles from proinflammatory factors in the progression of intestinal inflammation, and their upregulation is usually associated with a protective effect on the intestinal response to inflammation (Kuhn et al, 2018).…”