Upregulation of TLR4 mRNA Expression Levels in Broiler Chickens Under Acute Heat Stress

Huang, Shucheng

doi:10.1590/1806-9061-2016-0344

Cited by 26 publications

(16 citation statements)

References 44 publications

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“…This downregulation of TLR4 was neither observed in any other part of the intestine of animals receiving the oral LPS bolus nor in any part of the intestine of heat stressed animals. This finding is in contrast with other studies, as they could see either an increase of the expression of TLR4 in the duodenum [ 48 ] or both in the jejunum and ileum [ 19 ] in heat stressed broilers. Increased TLR4 expression is often associated with gut barrier failure [ 49 ].…”

Section: Discussioncontrasting

confidence: 99%

“…Among them, HSP70 and HSP90 play an essential role in the regulation of protein homeostasis during physiological as well as pathological conditions [ 50 , 51 ]. Heat stress is known to affect the expression of HSP70 [ 19 , 48 , 52 ]; therefore, it was not surprising that HSP70 was also upregulated with heat stress alone (up to 6.7 fold-increase). However, the potentiation of this effect when the birds received the oral LPS bolus in combination with heat stress was unexpected.…”

Section: Discussionmentioning

confidence: 99%

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Endotoxin Translocation and Gut Inflammation Are Increased in Broiler Chickens Receiving an Oral Lipopolysaccharide (LPS) Bolus during Heat Stress

Reisinger¹,

Emsenhuber²,

Doupovec³

et al. 2020

Toxins

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Lipopolysaccharides (LPS), also termed endotoxins, are the major component of the outer membrane of Gram-negative bacteria. In general, endotoxins in the intestine are considered harmless in healthy animals. However, different stressors, such as heat stress, can lead to a compromised gut barrier, resulting in endotoxin translocation. Chickens are considered to be less sensitive to the effects of LPS compared with other species, for example, humans, pigs, or calves, probably because of the lack of the functional-specific TRAM-TRIF signalling pathway (MyD88-independent). Therefore, six LPS preparations (three different strains with two different preparation methods each) were compared in murine macrophages and characterized according to their MyD88-dependent pathway activation. All tested LPS preparations induced a strong inflammatory response after 4 and 24 h on a murine macrophage cell line. However, there was a similar strong response in the gene expression profile as well as production of nitrite oxide and TNF-alpha from LPS of different strains and preparation methods. On the basis of the results of the in vitro study, one LPS preparation was chosen for the subsequent in vivo study with broilers to assess the effect of an oral LPS bolus (E. coli O55:B5 phenol extracted; 2 mg/kg b.w.) during heat stress conditions (10 h, 36 °C). The most pronounced effects were seen in broilers receiving the oral LPS bolus during heat stress conditions. The endotoxin activity in the intestine as well as the serum concentration of the 3-OH C14 (part of LPS) were increased. In addition, an increased expression of genes related to inflammation and stress response (e.g., IL-6, IL-1beta, HSP70) was observed, whereas the expression of genes associated with gut health (e.g., MUC2, FABP2) was decreased. To conclude, an increase of intestinal LPS combined with heat stress can pose a risk to animal health.

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Section: Discussioncontrasting

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Endotoxin Translocation and Gut Inflammation Are Increased in Broiler Chickens Receiving an Oral Lipopolysaccharide (LPS) Bolus during Heat Stress

Reisinger¹,

Emsenhuber²,

Doupovec³

et al. 2020

Toxins

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“…However, in chicks subjected to CHS, the TLR2 mRNA level was higher after 1 D, and the mRNA level of TLR4 was lower after 7 D of CHS in TM groups than that in controls. Formerly, it was reported that acute heat stress increased the expression of TLR2 and TLR4 in broiler chickens ( Huang, 2017 , Al-Zghoul et al., 2019 ). Moreover, it was shown that TM did not affect the basal mRNA levels of TLR2 and TLR4 in broiler chickens in thermoneutral conditions, while during acute heat stress, TM resulted in enhanced TLR2 and TLR4 expression ( Al-Zghoul et al., 2019 ).…”

Section: Discussionmentioning

confidence: 99%

“…The proinflammatory cytokines are produced during stressful conditions and are very important to regulate the acute phase response, which is an innate response that regenerate injured tissues ( Kushner, 1993 ). Heat stress was also found to increase the expression of toll-like receptor 4, a pathogen recognition receptor that is an important protein in the innate immunity ( Huang, 2017 ).…”

Section: Introductionmentioning

confidence: 99%

Effects of thermal manipulation of eggs on the response of jejunal mucosae to posthatch chronic heat stress in broiler chickens

Al‐Zghoul

Saleh

2020

Poultry Science

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In this study, the aim was to investigate effects of chronic heat stress ( CHS ) on the mRNA levels of proinflammatory cytokines (interleukin [ IL ]-6, IL-8, IL-1β, and tumor necrosis factor alpha [ TNF-α ]), toll-like receptors (TLR2 and TLR4), heat shock proteins (Hsp70, heat shock transcription factor [ HSF ]-1, and HSF3) and antioxidant enzymes (catalase, glutathione peroxidase, NADPH oxidase, and superoxide-dismutase) in the jejunal mucosae of broiler chickens subjected to thermal manipulation ( TM ) during embryogenesis. TM was carried out at 39°C and 65% relative humidity ( RH ) for 18 h daily from embryonic days 10 to 18. Control group was incubated at 37.8°C and 56% RH. CHS was induced by raising the temperature to 35°C for 7 D throughout posthatch days 28 to 35. On post-hatch-day 28 (day zero of CHS) and after 1, 3, 5, and 7 D of CHS, the jejunal mucosae were collected from both groups to evaluate the mRNA levels by real-time reverse transcription-PCR analysis. On day zero of CHS, the mRNA levels of antioxidant enzymes, TLRs, HSF3, IL-1β, and TNF-α were not significantly different between TM and control groups, while the levels of IL-6, IL-8, and HSF1 were lower and the level of Hsp70 was higher in TM. However, during CHS, the mRNA levels of antioxidant enzymes, IL-1β, TNF-α, TLR4, and HSF1 were significantly lower in TM than in controls, while the levels of TLR2 and IL-8 were significantly higher in TM than in controls. In addition, TM led to significant increase of mRNA levels of IL-6 and HSF3 after 1 D and Hsp70 after 3 D of CHS and to significant decrease of mRNA levels of IL-6 after 3 and 5 D, HSF3 after 7 D, and Hsp70 after 5 D of CHS. Results of this study suggest that TM led to altered posthatch antioxidant, immunological, and Hsp response to CHS in the jejunal mucosae of broiler chickens, probably indicating that TM may mitigate the adverse effects of CHS.

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“…Al-Zghoul, Saleh, and Ababneh [22] found that TLR4 mRNA expression level was upregulated in the spleens and livers of broilers under acute heat stress. The expression of TLR2 in the spleens of broilers was significantly upregulated by short-term acute heat stress with a rapid increase of 16 • C for 10 h [39]. Zhang et al [40] found that TLR4 in the spleens of triploid carp was rapidly elevated after being infected by Aeromonas hydrophilia (a Gram-negative bacterium) for six hours.…”

Section: Discussionmentioning

confidence: 99%

Effect of Intermittent and Mild Cold Stimulation on the Immune Function of Bursa in Broilers

Liu

Xue

et al. 2020

Animals

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Cold stress causes growth performance to decrease and increases production costs. Cold adaptation can enhance immune function and alleviate the negative impact caused by the stress condition. The study investigated the effect of intermittent and mild cold stimulation on the immune function of the bursa of Fabricius in broilers. A total of 400 healthy one-day-old broilers were divided into the control group (CC) and cold stimulation (CS) groups. The CC group was raised at a conventional raising temperature of broilers, while the CS groups were raised at 3°C below the temperature of the CC for three-, four-, five-, or six-hour periods at one-day intervals from 15 to 35 days of age (D35), denoted CS3, CS4, CS5, and CS6, respectively. Subsequently, they were raised at 20°C from 36 to 49 days of age (D49). The expression levels of TLRs, cytokines, and AvBDs were determined to access the immune function of bursa in broilers. After 21-day IMCS (at D36), the expression levels of TLR1, TLR15 and TLR21, interleukin (IL)-8, and interferon (IFN)-γ, as well as AvBD8 in CS groups, were lower than those in CC (p < 0.05). The expression levels of TLR3, TLR4 and TLR7, were decreased in the CS3, CS5, and CS6 groups (p < 0.05), but there were no significant differences in both the CC and CS4 groups (p > 0.05). When the IMCS ended for 14 days (at D49), the expression levels of TLR2, TLR3, TLR5, TLR7, TLR15, and TLR21, and IL-8, as well as AvBD2, AvBD4 and AvBD7 in CS groups, were lower than those in CC (p < 0.05). In addition to CS4, the expression levels of TLR1, IFN-γ, and AvBD8 in CS3, CS5, and CS6 were still lower than those in CC (p < 0.05). We concluded that the intermittent and mild cold stimulation could regulate immunoreaction by modulating the production of TLRs, cytokines, and AvBDs in the bursa, which could help broilers adapt to low ambient temperature and maintain homeostasis.

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Upregulation of TLR4 mRNA Expression Levels in Broiler Chickens Under Acute Heat Stress

Cited by 26 publications

References 44 publications

Endotoxin Translocation and Gut Inflammation Are Increased in Broiler Chickens Receiving an Oral Lipopolysaccharide (LPS) Bolus during Heat Stress

Endotoxin Translocation and Gut Inflammation Are Increased in Broiler Chickens Receiving an Oral Lipopolysaccharide (LPS) Bolus during Heat Stress

Effects of thermal manipulation of eggs on the response of jejunal mucosae to posthatch chronic heat stress in broiler chickens

Effect of Intermittent and Mild Cold Stimulation on the Immune Function of Bursa in Broilers

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