Skip to main content

Chronic heat stress promotes liver inflammation in broilers via enhancing NF-κB and NLRP3 signaling pathway

Abstract

Background

This study investigated the effects of chronic heat stress on liver inflammatory injury and its potential mechanisms in broilers. Chickens were randomly assigned to the 1-week control group (Control 1), 1-week heat stress group (HS1), 2-week control group (Control 2), and a 2-week heat stress group (HS2) with 15 replicates per group. Broilers in the heat stress groups were exposed to heat stress (35 ± 2 °C) for 8 h/d for 7 or 14 consecutive days, and the rest of 26 hours/day were kept at 23 ± 2 °C like control group broilers. Growth performance and liver inflammatory injury were examined for the analysis of liver injury.

Results

The results showed that heat stress for 2 weeks decreased the growth performance, reduced the liver weight (P < 0.05) and liver index (P < 0.05), induced obvious bleeding and necrosis points. Liver histological changes found that the heat stress induced the liver infiltration of neutrophils and lymphocytes in broilers. Serum levels of AST and SOD were enhanced in HS1 (P < 0.01, P < 0.05) and HS2 (P < 0.01, P < 0.05) group, compared with control 1 and 2 group broilers. The MDA content in HS1 group was higher than that of in control 1 group broilers (P < 0.05). Both the gene and protein expression levels of HSP70, TLR4 and NF-κB in the liver were significantly enhanced by heat stress. Furthermore, heat stress obviously enhanced the expression of IL-6, TNF-α, NF-κB P65, IκB and their phosphorylated proteins in the livers of broilers. In addition, heat stress promoted the activation of NLRP3 with increased NLRP3, caspase-1 and IL-1β levels.

Conclusions

These results suggested that heat stress can cause liver inflammation via activation of the TLR4-NF-κB and NLRP3 signaling pathways in broilers. With the extension of heat stress time, the effect of heat stress on the increase of NF-κB and NLRP3 signaling pathways tended to slow down.

Peer Review reports

Background

The poultry industry is growing across the world to fulfill the increasing demands of poultry meat and eggs. Heat stress is a top environmental concern in poultry industry worldwide, being potentially triggered by a variety of conditions, such as failure of ventilation, climatic conditions, stocking density, humidity and temperature controls. Among them, high ambient temperature plays a significant role Heat stress jeopardizes human and animal health and results in major economic losses in public health care and livestock production [1]. When the body exposed with heat stress, body temperature, respiratory rate, heart rate and rectal temperature will increase adaptively, which will affect the feed intake and production efficiency of poultry, thus adversely affecting the production economy [2]. In addition, long-term genetic selection of poultry for improved performance induced higher metabolic heat production and increased sensitivity to heat stress [3]. Research has shown that heat stress causes average annual economic losses of 128–240 million dollars for poultry industries in the United States, and the unfavorable influence has progressively increased as global temperatures rise [4]. Alleviating heat stress is important to reduce the economic loss of the livestock industry.

The liver is sensitive to ambient stress [5]. Research has found that heat stress can induce liver oxidative stress and reduce the immune responses of laying hens, which results in decreased poultry production performance, such as reduced body weight and food consumption [6]. Continuous exposure to high temperature in broilers can lead to liver tissue damage and decrease nonspecific immunity [7] and have other negative effects on the immune response [8]. Moreover, the intestinal stress caused by high temperature results in bacterial translocation and unbalanced intestinal flora and induces intestinal endotoxin entry into the liver through the internal circulation [9].

Innate immune cells in the liver recognize dangerous substances or damaged cells through pattern recognition receptors (PRRs), thus activating TLR4 signalling to promote inflammatory responses [10]. NF-κB, which acts downstream of TLR4 [11] and other immune receptors [12], can increase the overproduction of proinflammatory interleukin 6 (IL-6), IL-1β and tumour necrosis factor-alpha (TNF-α), which leads to the occurrence of inflammatory response [13]. NF-κB activates NLRP3 while inducing a variety of inflammatory chemokines [14], cytokines and cytokine precursors, including pre-IL-1β, and is therefore important for inflammasome initiation and assembly [15]. However, whether heat stress mediates inflammation in the liver of broilers and its relationship with NF-κB-NLRP3 are still unclear. In this study, we designed a model of chronic heat stress in broilers to investigate whether heat stress activates NF-κB-NLRP3 to exacerbate liver inflammation.

Results

Chronic heat stress inhibited the growth performance of broilers

The growth performance indices of broilers mainly include body weight growth and feed conversion capacity. The daily body weight and feed intake of broilers were monitored in this study, and the results were shown in Table 1. Compared with the control 2 group, the body weight gain of the broilers in the HS2 group was significantly decreased (from 412.95 ± 96.01 to 300.01 ± 36.50, P < 0.01), the feed intake and feed conversion ratio were also inhibited by heat stress, but the effect was not significant. The above 3 indicators had no significance between control 1 group and HS1 group. With increased heat stress time, these adverse reactions gradually enhanced, the growth performance of the broilers was significantly affected by heat stress for 2 weeks.

Table 1 Effects of heat stress on growth performance of broilers

Effects of heat stress on liver necropsy and histological changes in broilers

As shown in Fig. 1, the livers of the broilers after necropsy were observed that the texture of the liver surface in the broilers of the control 1 group (a) and the control 2 group (c) was uniform, without obvious bleeding and necrosis points. HS1 group (b) and HS2 group (d) broilers showed obvious bleeding and necrosis points on the liver surface. Liver histological changes were observed in Fig. 1B. There were no alterations in the morphology of liver in control group broilers. However, compared with the control group broilers, the infiltration of neutrophils and lymphocytes were observed in heat stress group broilers. The results showed that heat stress had a promotion on liver tissue damage.

Fig. 1
figure 1

Effects of heat stress on liver changes of broilers. A Liver necropsy changes. (a) control 1 group; (b) HS1 group; (c) control 2 group; (d) HS2 group Yellow triangle represents necrosis points. B Liver histological changes. Red arrow represents neutrophils infiltration. Red triangle represents lymphocytes infiltration

Effects of heat stress on liver index and enzymatic activity changes in broilers

Liver weight and liver index were measured (Fig. 2) and the results showed that heat stress for 2 weeks significantly reduced the above 2 indicators (P < 0.05, P < 0.05, respectively), compared with control 2 group. But, the 2 indicator above had no significance between control 1 group and HS1 group (Fig. 2). Compared with control 1 or 2 groups, heat stress for 1 or 2 weeks significantly enhanced serum AST and SOD levels, but had no change in ALT level. The MDA content in HS1 group was higher than that of in control 1 group broilers (P < 0.05).

Fig. 2
figure 2

Effects of heat stress on liver of broilers. A Liver weight of broilers. B Liver index of broilers. Serum (C) ALT and (D) AST levels. Liver (E) MDA and (F) SOD level in broilers. *P < 0.05, **P < 0.01 vs. control 1. #P < 0.05, ##P < 0.01 vs. control 2

Chronic heat stress enhanced the protein expression of TNF-α and IL-6 in the livers of the broilers

As shown in Fig. 3, heat stress significantly increased the protein expression of IL-6 in the liver after 1 and 2 weeks of heat stress compared with those of the control 1 and 2 groups (P < 0.01, P < 0.01, respectively). The TNF-α protein levels in the broilers subjected to heat stress for 1 and 2 weeks were higher than that of in control 1 and 2 group broilers (P < 0.01, P < 0.01, respectively).

Fig. 3
figure 3

Effects of heat stress on liver proteins levels of TNF-α and IL-6 in broilers. A Protein expressions of liver TNF-α and IL-6 in broilers. Relative expressions of (B) IL-6 and (C) TNF-α. **P < 0.01 vs. control 1; ##P < 0.01 vs. control 2

Chronic heat stress activated the NLRP3 inflammasome in livers broilers

As shown in Fig. 4, the NLRP3 and caspase 1 protein levels in the HS1 and HS2 groups were both significantly increased compared with those of the control 1 and 2 groups (P < 0.01, P < 0.01, P < 0.01, P < 0.01). The levels of cleaved IL-1β/pro-IL-1β in the livers of the broilers in the HS1 and HS2 groups were obviously higher than that of in the control 1 and 2 groups (P < 0.01, P < 0.01). The trend of cleaved IL-1β/pro-IL-1β was consistent with the protein expression of NLRP3 and caspase 1.

Fig. 4
figure 4

Effects of heat stress on protein expressions of NLRP3 pathways in broilers. A Protein expressions of NLRP3 pathways in liver of broilers were measured by western blot. Relative expression of (B) NLRP3, C caspase 1 and (D) cleaved-IL-1β/pro-IL-1β. **P < 0.01 vs. control 1; ##P < 0.01 vs. control 2

Chronic heat stress strengthened NF-κB pathways in the livers of the broilers

We simultaneously detected the expression of NF-κB, IκB-α and their phosphorylated proteins. The results are shown in Fig. 5. Compared with the control 1 and 2 groups, heat stress for 1 and 2 weeks significantly increased the ratio of phosphorylation of NF-κB to NF-κB (P < 0.01 and P < 0.01, respectively) and enhanced the ratio of phosphorylation to unphosphorylation of IκB-α (P < 0.01 and P < 0.01, respectively) .

Fig. 5
figure 5

Effects of heat stress on NF-κB pathways in liver of broilers. A Protein expressions of NF-κB pathways in liver of broilers. Relative expression of (B) p-p65/p65 and (C) p-IκB-α/IκB-α. **P < 0.01 vs. control 1; ##P < 0.01 vs. control 2

Chronic heat stress promoted the protein expression of TLR4 and HSP70 in the livers of the broilers

To confirm the dependence of inflammation responses on these key factors, the relative gene expressions of TLR4, NF-kB, and Hsp70 in liver of broilers were examined. As shown in Fig. 6, the protein expressions of TLR4 and HSP70 in the liver of the broilers was measured. Heat stress for 1 and 2 weeks significantly upregulated the protein expression of TLR4 compared to that of the control 1 and 2 groups (P < 0.01 and P < 0.01, respectively). The HSP70 protein has a protective effect on cells, and its nonspecific expression can be increased when the body is subjected to stress. Our results showed that compared with that of the control 1 and 2 groups, the protein expression of HSP70 in the HS1 and HS2 groups were enhanced (P < 0.01 and P < 0.01, respectively).

Fig. 6
figure 6

Effects of heat stress on proteins expressions of TLR4 and HSP70 in liver. A Proteins levels of TLR4 and HSP70 in liver of broilers. Relative expression of (B)TLR4 and (C) HSP70. **P < 0.01 vs. control 1; ##P < 0.01 vs. control 2

Chronic heat stress upregulated the gene expression of TLR4, HSP70 and NF-κB in the livers of the broilers

As shown in Fig. 7, heat stress for 1 and 2 weeks enhanced TLR4 gene expression (P < 0.01 and P < 0.01, respectively), especially at 2 weeks of heat stress. An increase in HSP70 mRNA expression was observed in the liver after heat stress for 1 and 2 weeks compared to that of the control 1 and 2 groups (P < 0.01 and P < 0.01, respectively). Consistently, NF-κB gene expression was also significantly upregulated during heat stress.

Fig. 7
figure 7

Effects of heat stress on genes expressions of TLR4, HSP70 and NF-κB in liver of broilers. A TLR4, B HSP70 and C NF-κB genes expressions in liver were measured by qRT-PCR. **P < 0.01 vs. control 1; ##P < 0.01 vs. control 2

Discussion

High temperatures or hot climates have adverse impacts on the growth performance of poultry due to their higher water intake and lower feed intake. Moreover, high temperature affects the digestive and absorptive function of the gastrointestinal tract and results in a significantly lower weight gain (WG) and feed conversion rate (FCR). High temperature also causes tissue damage, especially damage to the intestine and liver, which affects the normal function of poultry [16, 17]. Heat stress for 2 week decreased weight gain, and heat stress for 1 and 2 weeks reduced the body weight of broilers. The relative organ weight reflects the growth and development of organs to some degree and then affects their functions [18]. Under continuous heat stress, the organ index of the liver and other immune organs and cellular immunity decrease [17, 19], which was consistent with our results. In this study, heat stress for 2 weeks decreased the body weight, liver weight and liver index of the broilers, indicating that heat stress impaired liver growth and development in the broilers. Moreover, the heat-stressed broilers showed obvious bleeding and necrosis points on the liver. Liver histological changes indicated that heat stress induced the infiltration of neutrophils and lymphocytes in liver of heat stress group broilers. As the largest digestive organ in the broilers, liver injury may affect the digestive and absorption functions of the body, which may explain why the growth performance of the broilers decreased to a certain extent after heat stress in the experiment. However, the relationship between the inflammatory cell infiltration of the broiler and susceptibility to heat stress is not fully understood.

One organ capable of exerting strong influence on both bird growth and thermoregulation is the liver. This organ has recently proved effective as a subject for studies for its highly susceptible to heat stress. The overexpression of HSP70 is an indicator of various stress responses, including heat stress. In this study, increased HSP70 mRNA and protein levels were observed in the livers of the broilers in the heat stress group. Extracellular or exosomal-bound HSP70 binds to TLR2 or TLR4 to activate the inflammatory response in animals [20, 21]. TLR4 is thought to be the endotoxin receptor that receives the validation response [22]. Activation of TLR4 stimulates the associated inflammatory signalling pathways. Research has shown that heat stress can significantly upregulate the TLR4 mRNA expression in the liver of broilers [17]. Activation of TLR4 can activate NF-κB, cause the synthesis and secretion of proinflammatory cytokines, and further amplify the inflammatory response. Research has shown that NF-κB protein expression is significantly increased by heat stress [23]. Our results showed that heat stress for 1 and 2 weeks upregulated the gene and protein expression of TLR4 and NF-κB, and heat stress also increased the ratio of NF-κB and IκB-α protein phosphorylation to nonphosphorylation. We further detected the expression levels of inflammation-related proteins in the liver. Our results showed that heat stress upregulated TNF-α and IL-6 protein levels in the livers of the broilers. Therefore, heat stress activates the NF-κB signalling pathway and promotes the secretion of the inflammatory factors TNF-α and IL-6, leading to the occurrence of inflammation in the liver of the broilers.

Heat stress can disrupt metabolic homeostasis in the liver and throughout the system, and the disorder is associated with inflammation [24]. NLRP3 inflammasome is a type of multiprotein complex, and its abnormal activation and regulation are related to the development of various inflammatory diseases. Yang’s study found that the NF-κB/NLRP3 signalling pathway is inhibited in response to acute heat stress [25], and Greene’s study also confirmed that heat stress can reduce the NLRP3 inflammasome [26]. However, most studies have shown that NLRP3 protein levels increase with heat stress temperature [27]. Pei’s study showed that the protein level of NLRP3 increased with the extension of exposure time under heat stress [28]. Studies have shown that stress triggers activation of the NLRP3 inflammasome [29], and excessive accumulation of the inflammasome can trigger inflammation, which mediates liver injury [30]. In addition to NLRP3 activation, heat stress can also promote the activation of the NF-κB signalling, P38, and ERK pathways [31, 32]. Although, there are lots of researches on inflammatory diseases and NLRP3 inflammasome in mice and human, few studies on the changes of NLRP3 inflammasome in liver of broilers treated with heat stress. Therefore, we observed protein changes in the NLRP3 pathway of the inflammasome in heat stressed broilers. The results showed that heat stress significantly increased the NLRP3 protein in the liver of broilers, and the protein levels of the NLRP3 downstream genes caspase-1 was also increased in the heat stress group, compared with the control group. The content of IL-1β precursor was significantly decreased, while the content of IL-1β in the mature and caspase-1 were significantly increased. The results indicated that heat stress activated NLRP3 pathway and the activation of NLRP3 inflammasome eventually leads to the activation of caspase1 and the secretion of IL-1β.

Conclusion

In this study, heat stress inhibited broiler growth performance, increased liver inflammatory cell infiltration, and promoted the release of inflammatory factors in liver of broilers. The expression of TLR4 in the livers of broilers under heat stress was similar to the expression of NLRP3 and the inflammatory factors NF-κB, indicating that heat stress promoted liver inflammatory injury via activation of the TLR4-NF-κB and NLRP3 signaling pathways in broilers (Fig. 8).

Fig. 8
figure 8

Mechanism of heat stress induced liver inflammation injury of broilers. Heat stress activates TLR4-NF-κB and NLRP3 signaling pathway, which induced the secretion of pro-inflammatory factors

Methods

Animals treatment

Sixty two-week-old Ma chickens .were purchased from a commercial hatchery (Nanhai Poultry Corporation, Foshan, China). Ma chickens are a pure line of local Qing Yuan Ma Chickens. One week of adaptive feeding, twenty-one-day-old male broilers were randomly divided into 1-week control group (Control 1), 1-week heat stress group (HS1), 2-week control group (Control 2) and 2-week heat stress group (HS2), with 15 replicates in each group. The control group was kept at 23 ± 2 °C, while the heat stress group was kept at the 35 ± 2 °C, and the humidity control as about 70%. The broilers of heat stress groups continuous treatment with high temperature for 8 h every day (8:00–16:00 every day) for 1 or 2 weeks. All broilers had freely drinking water and basal diet. The broilers feed were provided by WENS FOODSTUFF GROUP CO.,LTD, including corn, wheat, soybean meal, soybean oil and other conventional feed additives, amino acids, trace elements and vitamins. We recorded the body weight and the amount of feed consumed every day which were used to analyze the average weight gain (WG), feed intake and feed conversion ratio (GFR). At the end of heat stress, blood samples were taken from the jugular vein and used for the measurement of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), all broilers were sacrificed quickly by CO2 inhalation, and liver samples were collected for subsequent testing.

Pathological changes and the organ index of liver

The liver tissues of broilers were photographed to observe the changes of pathological injury during the slaughter of broilers. Complete liver was taken, washed with autoclaving saline, dried with absorbent paper, weighed and recorded for calculating organ index (organ index = (liver weight / body weight) × 100%).

The liver tissue was fixed with 4% paraformaldehyde for 48 h and dehydrated with ethanol, and then the tissue was embedded in paraffin. The liver wax block was cut into slices (5 μm). Sections were subjected to hematoxylin and eosin (H&E) staining and then observed under an optical microscope (Bio-Rad, USA).

Enzymatic activity analysis

Serum ALT and AST levels were analyzed using Alanine aminotransferase Assay Kit (C009–2-1) and the Aspartate aminotransferase Assay Kit (C010–2-1). Liver malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured with malondialdehyde (MDA) assay kit (A003–1-2) and superoxide dismutase (SOD) assay kit (A001–3-2) The four kits were provided by Nanjing Jiancheng Bioengineering Institute (Nanjing, China).

Western blot analysis

Liver samples were extract with a lysate containing RIPA and phosphatase-inhibitors and phenylmethylsulfonyl fluoride (PMSF) on ice, supernatant protein quantification by BCA kit (Beyoutime, Shanghai, China) before centrifuged at 13000 r/min at 4 °C for 10 min. Proteins (20–40 μg from each sample) were separated on SDS-PAGE gels and transferred to polyvinylidene fluoride (PVDF) membrane. Then, the membrane was blocked with 5% skimmed milk (skim milk powder in Tris-buffered saline-Tween 20) for 1 hour and incubated with primary antibodies (IL-6, TNF-α, NLRP3, caspase 1, pro-IL-1β, cleaved- IL-1β, p-NF-κB p65, NF-κB p65, p-IκB-α, IκB-α, TLR4, HSP70 and GAPDH. Cell Signaling Technology, Danvers, MA, USA). Subsequently, the membrane was incubated with secondary antibodies which contain peroxidase-conjugated, followed by visualized with the Chemiluminescence System. The relative intensity of target protein was analyzed by the Image J software.

Quantitative real-time PCR

Total RNA from the liver tissue using the Trizol reagent (Ambion, Austin, TX, USA), and reversely transcribed through 1st Strand cDNA Synthesis kit (Takara, Tokyo, Japan) according to the protocol. Then, quantitative real-time polymerase chain reaction using the TB Green™ Premix Ex Taq™ II (Takara, Tokyo, Japan) and a Roche LightCycler 480 system (Roche, Basel, Switzerland). Gene mRNA levels were normalized using the expression of housekeeping gene β-actin and the relative fold changes were calculated using the 2-ΔΔCt method. All primers used for qRT-PCR are listed in Table 2.

Table 2 The primers used in qPCR are as Table 2 follows

Statistics

Data are expressed as means ± standard deviation. Statistical significance was performed using a two-tailed Student’s test. P < 0.05 were considered statistically significant, *P < 0.05, **P < 0.01 vs. control 1; #P < 0.05, ##P < 0.01 vs. control 2. SPSS 24.0 software (SPSS, Chicago, USA) was used for statistical analysis. The measured data were statistically ploted with GraphPad Prism 8.0 software.

Availability of data and materials

All data generated or analyzed during this study are included in this published article.

Abbreviations

HS:

Heat stress

HSP70:

Heat shock protein 70

WG:

weight gain

FCR:

Feed conversion rate

PRRs:

Pattern recognition receptors

TLR4:

Toll-like receptor 4

NF-κB:

Nucleus factor kappa B

NLRP3:

Nucleotide-binding oligomerization domain-like Receptor Family, Pyrin Domain Containing 3

References

  1. Lara LJ, Rostagno MH. Impact of heat stress on poultry production. Animals (Basel). 2013;3(2):356–69. https://doi.org/10.3390/ani3020356.

    Article  PubMed  PubMed Central  Google Scholar 

  2. Das R, Sailo L, Verma N, Bharti P, Saikia J, Imtiwati, et al. Impact of heat stress on health and performance of dairy animals: a review. Vet World 2016 2016;9(3):260–268. https://doi.org/10.14202/vetworld.2016.260-268.

  3. Narinc D, Erdogan S, Tahtabicen E, Aksoy T. Effects of thermal manipulations during embryogenesis of broiler chickens on developmental stability, hatchability and chick quality. Animal. 2016;10(8):1328–35. https://doi.org/10.1017/S1751731116000276.

    CAS  Article  PubMed  Google Scholar 

  4. Mohammed A, Mahmoud M, Murugesan R, Cheng HW. Effect of a Synbiotic supplement on fear response and memory assessment of broiler chickens subjected to heat stress. Animals (Basel). 2021;11(2). https://doi.org/10.3390/ani11020427.

  5. Gao B. Basic liver immunology. Cell Mol Immunol. 2016;13(3):265–6. https://doi.org/10.1038/cmi.2016.09.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  6. Robinson MW, Harmon C, O'Farrelly C. Liver immunology and its role in inflammation and homeostasis. Cell Mol Immunol. 2016;13(3):267–76. https://doi.org/10.1038/cmi.2016.3.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  7. Fathi MM, Ebeid TA, Al-Homidan I, Soliman NK, Abou-Emera OK. Influence of probiotic supplementation on immune response in broilers raised under hot climate. Br Poult Sci. 2017;58(5):512–6. https://doi.org/10.1080/00071668.2017.1332405.

    CAS  Article  PubMed  Google Scholar 

  8. Farag MR, Alagawany M. Physiological alterations of poultry to the high environmental temperature. J Therm Biol. 2018;76:101–6. https://doi.org/10.1016/j.jtherbio.2018.07.012.

    CAS  Article  PubMed  Google Scholar 

  9. Nawab A, Li G, An L, Wu J, Chao L, Xiao M, et al. Effect of curcumin supplementation on TLR4 mediated non-specific immune responses in liver of laying hens under high-temperature conditions. J Therm Biol. 2019;84:384–97. https://doi.org/10.1016/j.jtherbio.2019.07.003.

    CAS  Article  PubMed  Google Scholar 

  10. Bieghs V, Trautwein C. The innate immune response during liver inflammation and metabolic disease. Trends Immunol. 2013;34(9):446–52. https://doi.org/10.1186/s40781-016-0122-4.

    CAS  Article  PubMed  Google Scholar 

  11. Tang LP, Li WH, Liu YL, Lun JC, He YM. Heat stress aggravates intestinal inflammation through TLR4-NF-kappaB signaling pathway in ma chickens infected with Escherichia coli O157:H7. Poult Sci. 2021;100(5):101030. https://doi.org/10.1016/j.psj.2021.101030.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  12. Vallabhapurapu S, Karin M. Regulation and function of NF-kappaB transcription factors in the immune system. Annu Rev Immunol. 2009;27:693–733. https://doi.org/10.1146/annurev.immunol.021908.132641.

    CAS  Article  PubMed  Google Scholar 

  13. Kagan JC, Medzhitov R. Phosphoinositide-mediated adaptor recruitment controls toll-like receptor signaling. Cell. 2006;125(5):943–55. https://doi.org/10.1016/j.cell.2006.03.047.

    CAS  Article  PubMed  Google Scholar 

  14. Zhong Z, Umemura A, Sanchez-Lopez E, Liang S, Shalapour S, Wong J, et al. NF-kappaB restricts Inflammasome activation via elimination of damaged mitochondria. Cell. 2016;164(5):896–910. https://doi.org/10.1016/j.cell.2015.12.057.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  15. Schroder K, Tschopp J. The inflammasomes. Cell. 2010;140(6):821–32. https://doi.org/10.1016/j.cell.2010.01.040.

    CAS  Article  PubMed  Google Scholar 

  16. Nawab A, Ibtisham F, Li G, Kieser B, Wu J, Liu W, et al. Heat stress in poultry production: mitigation strategies to overcome the future challenges facing the global poultry industry. J Therm Biol. 2018;78:131–9. https://doi.org/10.1016/j.jtherbio.2018.08.010.

    Article  PubMed  Google Scholar 

  17. Chen Y, Cheng Y, Wen C, Zhou Y. Protective effects of dietary mannan oligosaccharide on heat stress-induced hepatic damage in broilers. Environ Sci Pollut Res Int. 2020;27(23):29000–8. https://doi.org/10.1007/s11356-020-09212-2.

    CAS  Article  PubMed  Google Scholar 

  18. Guo S, Fu S, Xu Q, Zhang Z, Wang Y, Shen Z. Immune function of Chinese formula Qingwen Baidu granule in broilers. Cent Eur J Immunol. 2015;40(2):149–52. https://doi.org/10.5114/ceji.2015.52827.

    Article  PubMed  PubMed Central  Google Scholar 

  19. Bello AU, Sulaiman JA, Aliyu MS. Acute phase protein mRNA expressions and enhancement of antioxidant defense system in Black-meated Silkie Fowls supplemented with clove (Eugenia caryophyllus) extracts under the influence of chronic heat stress. J Anim Sci Technol. 2016;58:39. https://doi.org/10.1186/s40781-016-0122-4.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  20. Asea A, Kraeft SK, Kurt-Jones EA, Stevenson MA, Chen LB, Finberg RW, et al. HSP70 stimulates cytokine production through a CD14-dependant pathway, demonstrating its dual role as a chaperone and cytokine. Nat Med. 2000;6(4):435–42. https://doi.org/10.1038/74697.

    CAS  Article  PubMed  Google Scholar 

  21. Chalmin F, Ladoire S, Mignot G, Vincent J, Bruchard M, Remy-Martin JP, et al. Membrane-associated Hsp72 from tumor-derived exosomes mediates STAT3-dependent immunosuppressive function of mouse and human myeloid-derived suppressor cells. J Clin Invest. 2010;120(2):457–71. https://doi.org/10.1172/JCI40483.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  22. Chen Y, Zhang H, Cheng Y, Li Y, Wen C, Zhou Y. Dietary l-threonine supplementation attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage of broiler chickens at an early age. Br J Nutr. 2018;119(11):1254–62. https://doi.org/10.1017/S0007114518000740.

    CAS  Article  PubMed  Google Scholar 

  23. Oskoueian E, Abdullah N, Idrus Z, Ebrahimi M, Goh YM, Shakeri M, et al. Palm kernel cake extract exerts hepatoprotective activity in heat-induced oxidative stress in chicken hepatocytes. BMC Complement Altern Med. 2014;14:368. https://doi.org/10.1186/1472-6882-14-368.

    Article  PubMed  PubMed Central  Google Scholar 

  24. Komada T, Muruve DA. The role of inflammasomes in kidney disease. Nat Rev Nephrol. 2019;15:501–20. https://doi.org/10.1038/s41581–019-0158-z.

    Article  Google Scholar 

  25. Yang C, Luo P, Chen SJ, Deng ZC, Fu XL, Xu DN, et al. Resveratrol sustains intestinal barrier integrity, improves antioxidant capacity, and alleviates inflammation in the jejunum of ducks exposed to acute heat stress. Poult Sci. 2021;100(11):101459. https://doi.org/10.1016/j.psj.2021.101459.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  26. Greene ES, Emami NK, Dridi S. Research note: Phytobiotics modulate the expression profile of circulating inflammasome and cyto (chemo) kine in whole blood of broilers exposed to cyclic heat stress. Poult Sci. 2021;100(3):100801. https://doi.org/10.1016/j.psj.2020.10.055.

    CAS  Article  PubMed  Google Scholar 

  27. Chei S, Song JH, Oh HJ, Lee K, Jin H, Choi SH, et al. Gintonin-enriched fraction suppresses heat stress-induced inflammation through LPA receptor. Molecules. 2020;25(5):1019. https://doi.org/10.3390/molecules25051019.

    CAS  Article  PubMed Central  Google Scholar 

  28. Pei Y, Cao Y, Wang H, Fan M, Han X. Activation of NOD like receptor protein 3 signaling pathway in vascular endothelial cells induced by heat stress can be inhibited by ethyl pyruvate. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2020;32(11):1367–71. https://doi.org/10.3760/cma.j.cn121430-20200715-00527.

    Article  PubMed  Google Scholar 

  29. Espinosa-Garcia C, Atif F, Yousuf S, Sayeed I, Neigh GN, Stein DG. Progesterone attenuates stress-induced NLRP3 Inflammasome activation and enhances autophagy following ischemic brain injury. Int J Mol Sci. 2020;21(11). https://doi.org/10.3390/ijms21113740.

  30. Lebeaupin C, Proics E, de Bieville CH, Rousseau D, Bonnafous S, Patouraux S, et al. ER stress induces NLRP3 inflammasome activation and hepatocyte death. Cell Death Dis. 2015;6:e1879. https://doi.org/10.1038/cddis.2015.248.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  31. Song JH, Kim KJ, Chei S, Seo YJ, Lee K, Lee BY. Korean red ginseng and Korean black ginseng extracts, JP5 and BG1, prevent hepatic oxidative stress and inflammation induced by environmental heat stress. J Ginseng Res. 2020;44(2):267–73. https://doi.org/10.1016/j.jgr.2018.12.005.

    Article  PubMed  Google Scholar 

  32. Du D, Lv W, Su R, Yu C, Jing X, Bai N, et al. Hydrolyzed camel whey protein alleviated heat stress-induced hepatocyte damage by activated Nrf2/HO-1 signaling pathway and inhibited NF-kappaB/NLRP3 axis. Cell Stress Chaperones. 2021;26(2):387–401. https://doi.org/10.1007/s12192-020-01184-z.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

This project was supported by Sheng-Yuan, who provided experimental technical help.

Funding

Natural Science Foundation of Guangdong Province, China (Grant No. 2017A030310607). Guangdong Province Department of Agriculture and Rural Affairs (Grant No. 2019KJ119). Guangdong Science and Technology Department, China (Grant No. 2015A040404048). Department of education of Guangdong Province (Grant No. 2017GCZX006).

Author information

Authors and Affiliations

Authors

Contributions

Conceptualization and funding acquisition, Lu-Ping Tang and Yong-Ming He; Investigation, experiment and operation, Yi-Lei Liu and Kang-Ning Ding; Methodology and data curation, Xing-Ling Shen and Yu-Qing Liu; Software, Yi-An Zhang and Han-Xiao Liu; Validation and writing original draft, Yi-Lei Liu. The author(s) read and approved the final manuscript.

Corresponding author

Correspondence to Lu-Ping Tang.

Ethics declarations

Ethics approval and consent to participate

All animals work was adhered the fundamental principles of Basel Declaration and the ethical guidelines of International Council for Laboratory Animal Science (ICLAS). The animals work was approved by the Laboratory Animal Management Committee of Foshan University. The study was reported in accordance with ARRIVE guidelines.

Consent for publication

Not Applicable.

Competing interests

The authors declare that they have no competing interests.

The author confirms that the work described has not been published before and its publication has been approved by all co-authors.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Liu, YL., Ding, KN., Shen, XL. et al. Chronic heat stress promotes liver inflammation in broilers via enhancing NF-κB and NLRP3 signaling pathway. BMC Vet Res 18, 289 (2022). https://doi.org/10.1186/s12917-022-03388-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s12917-022-03388-0

Keywords

  • Heat stress
  • Broilers
  • Liver
  • NF-κB
  • NLRP3