Research Note: Phytobiotics modulate the expression profile of circulating inflammasome and cyto(chemo)kine in whole blood of broilers exposed to cyclic heat stress

Abstract

Heat stress ( HS ) is a critical concern to the poultry industry as it affects both productivity and well-being. Various managerial and nutritional strategies have been proposed to mitigate the negative effects of HS in chickens, with plant-based additives showing promise. Recently, we reported the positive effect of a phytogenic feed additive ( PFA ) on growth performance in HS birds. Owing to the antioxidant nature of these compounds, we sought to further explore the effect of PFA on whole blood circulating chemokines, cytokines, and inflammasomes in HS broilers. Broilers (600 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to 2 environmental conditions (12 h cyclic heat stress, HS, 35°C vs. thermoneutral condition [ TN ], 24°C) and fed 3 diets (control, PFA-C 250 ppm, PFA-C 400 ppm) in a 2 × 3 factorial design. After 21 d of cyclic HS, blood samples were collected for target gene expression analysis. HS upregulated the expression of superoxide dismutase 1 ( SOD1 ) and downregulated glutathione peroxidase-3 ( GPX-3 ), and there was diet × temperature interaction for SOD2, GPX-1, and GPX-3, where gene expression was increased by PFA-C250 during HS but was unchanged for PFA-C400. Plasma total antioxidant capacity ( TAC ) and malondialdehyde ( MDA ) content were increased by HS. Gene expression of interleukin-18 ( IL-18 ) was decreased by HS, without further effect of PFA. HS increased tumor necrosis factor α ( TNFα ), but this effect was mitigated by PFA-C400. C-C motif chemokine ligands 4 and 20 ( CCL4 and CCL20 ) showed a similar pattern to TNFα, with PFA-C400 ameliorating the negative effect of HS. The nucleotide-binding, leucine-rich repeat and pyrin domain containing 3 ( NLRP3 ) inflammasome was decreased by HS and further lowered by PFA-C400, but the nucleotide-binding oligomerization domain, leucine-rich repeat, and CARD domain containing 3 ( NLRC3 ) and nucleotide-binding, leucine-rich repeat containing X1 ( NLRX1 ) inflammasomes were increased by PFA under TN conditions, with no effects of HS. Heat shock proteins ( HSP ) and heat shock factors ( HSF ) were unaffected by PFA or HS. Together these data indicate that gene expression of circulating inflammatory factors are dysregulated during HS, and supplemental dietary PFA may be protective.

Heat Stress and Feed Restriction Distinctly Affect Performance, Carcass and Meat Yield, Intestinal Integrity, and Inflammatory (Chemo)Cytokines in Broiler Chickens

“…Dysregulation of circulating inflammatory factors during CHS was previously reported by our group which is not in line with the results of the current study. Compared to birds raised under thermoneutral condition, CHS (12 h/day; 35 • C) increased mRNA abundance of SOD1, TNF-α, CCL4, and CCL20, downregulated GPX3, IL18, and NLRP3 inflammasome, with no effect on HSPs, NLRC3 and NLRX1 inflammasomes (Greene et al, 2021b). Discrepancies might be due to the duration of HS (8 vs. 12 h/day).…”

“…HS causes multiple immune abnormalities in broiler chickens by impairing the developmental process and functional maturation of T-and B-cells in both primary and secondary lymphoid tissues (Hirakawa et al, 2020). Pro-inflammatory cytokines, including interleukin (IL)-1, IL2, IL6, IL18, and tumor necrosis factor (TNF)-α, are involved in the inflammatory response under HS, and excessive pro-inflammatory response may result in tissue damage (Helwig and Leon, 2011;Goel et al, 2021;Greene et al, 2021b). Plasma titers of anti-bovine serum albumin (BSA) immunoglobulin (Ig)Y, IgM, and IgA were lower in broiler chickens exposed to constant HS (35 • C) from day 22 to 36 than those of thermoneutral chickens immunized with BSA (Hirakawa et al, 2020).…”

“…Plasma titers of anti-bovine serum albumin (BSA) immunoglobulin (Ig)Y, IgM, and IgA were lower in broiler chickens exposed to constant HS (35 • C) from day 22 to 36 than those of thermoneutral chickens immunized with BSA (Hirakawa et al, 2020). Recently, we have shown that gene expression of circulating inflammatory factors are dysregulated during CHS (Greene et al, 2021b). CHS (12 h/day at 35 • C) upregulated the expression of superoxide dismutase (SOD)-1, TNF-α, and C-C motif chemokine ligand (CCL)-4 and CCL20; but, downregulated glutathione peroxidase (GPX)-3, IL18, and nucleotide-binding, leucine-rich repeat and pyrin domain containing (NLRP)-3 inflammasome.…”

“…CHS (12 h/day at 35 • C) upregulated the expression of superoxide dismutase (SOD)-1, TNF-α, and C-C motif chemokine ligand (CCL)-4 and CCL20; but, downregulated glutathione peroxidase (GPX)-3, IL18, and nucleotide-binding, leucine-rich repeat and pyrin domain containing (NLRP)-3 inflammasome. Heat shock proteins (HSP) and nucleotide-binding oligomerization domain, leucine-rich repeat, and CARD domain containing (NLRC)-3 and nucleotide-binding, leucine-rich repeat containing X1 (NLRX1) inflammasomes mRNA were unaffected by HS (Greene et al, 2021b).…”

Local and Systemic Cytokine, Chemokine, and FGF Profile in Bacterial Chondronecrosis with Osteomyelitis (BCO)-Affected Broilers

“…Amplification was achieved using Power SYBRGreen Master Mix (Life Technologies, Carlsbad, CA, USA) and real-time quantitative PCR (7500 Real Time System; Applied Biosystems, Foster City, CA, USA). The sequences for oligonucleotide primers for r18s, TNFα, IL-1β, IL-18, IL-3, IL-4, IL-10, IL-6, CRP, CCLL-4, CXCL-14, CCL-4, CCL-20, NLRP3, NLRC5, NLRX1, and NLRC3 were previously published [10,19,20]. Additional primers used were IL-17 (forward, 5 -CCTTGCTCCTGCTTGCTTTC-3 ; and reverse, 5 -AACCAATCGCTCCCCATTTT-3 ), IL-12B (forward 5 -TGCCCAGTGCCAGAAGGA-3 ; and reverse, 5 -TCAGTCGGCTGGTGCT CTT-3 ), and chemokines IL-8L1 (forward 5 -CAGAACCAAACCCAGGTGACA-3 ; and reverse, 5 -ACAGCCTTGCCCATCATCTT-3 ), IL-8L2 (forward 5 -TCCTGGTTTCAGCTGCT CTGT-3 ; and reverse, 5 -CGCAGCTCATTCCCCATCT-3 ), CCL-5 (forward 5 -TTTCTACAC CAGCAGCAAATGC-3 ; and reverse, 5 -GCCCCTTCCTGGTGATGAA-3 ).…”