The aim of the present study was to investigate the effect of selenium (Se) deficiency on the expression of the toll-like receptor (TLR) signal transduction pathway in the spleen of chickens and explore the relationship between the TLR4/TRIF/NF-κB signaling pathway and inflammatory spleen injury. A total of 200 one-day-old healthy broilers were allocated to two groups. The experimental group was fed a self-made low-Se diet (0.004 mg/kg) while the control group was fed a complete formula feed (0.2 mg/kg) for 15, 25, 35, 45, and 55 days, respectively. We observed histopathological changes in the chicken spleens. The messenger RNA(mRNA) expression levels of 8 kinds of ChTLRs, myeloid differential protein-88 (MyD88), toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β (TRIF), nuclear factor-κB (NF-κB), and cytokine (IL-6, TNF-α, IL-2, and IFN-γ) were detected via quantitative real-time PCR. Western blotting was used to detect the protein expression level of TLR4. Then principal component analysis (PCA) was used to analyze the correlation between the ChTLRs, MyD88, TRIF, and NF-κB. The results showed that the boundary between red pulp and white pulp was unclear, the number of lymphocytes decreased, and the nucleus was fragmented and dissolved in the experimental group at 25-55 days. At 15-45 days, the relative expression of TLR4 mRNA was higher than in the control group, and the difference was extremely significant on day 15 (P < 0.01).The relative expression of TRIF mRNA in the experimental group was higher than in the control group at 25-55 days, and the relative expression of NF-κB mRNA in the experimental group was higher than in the control group at 15-45 days. The relative expression of IL-6 mRNA in the experimental group was higher than in the control group at 15-45 days. The protein expression level of TLR4 in the experimental group was higher than in the control group at 15-45 days. The PCA results showed that there was a strong correlation between TLR4, TRIF, and component 1. The results suggest that TLR4 plays an important role in regulating the expression of inflammatory cytokines in the spleens of Se-deficient chickens, and Se deficiency may cause inflammatory injury through the TLR4/TRIF/NF-κB signaling pathway in chicken spleen.

中文翻译：

---

硒缺乏通过 TLR4/TRIF/NF-κB 信号通路导致鸡脾炎性损伤。

本研究旨在探讨硒（Se）缺乏对鸡脾脏Toll样受体（TLR）信号转导通路表达的影响，并探讨TLR4/TRIF/NF-κB与TLR4/TRIF/NF-κB之间的关系。信号通路与炎性脾损伤。总共 200 只 1 日龄健康肉鸡被分配到两组。实验组饲喂自制低硒日粮（0.004 mg/kg），对照组饲喂全量配方饲料（0.2 mg/kg），时间分别为15、25、35、45和55天。我们观察到鸡脾脏的组织病理学变化。8种ChTLRs、髓系分化蛋白88（MyD88）、含toll-interleukine-1受体结构域的接头诱导干扰素-β（TRIF）、核因子-κB（NF-κB）的信使RNA（mRNA）表达水平), 和细胞因子 (IL-6, TNF-α、IL-2 和 IFN-γ）通过实时定量 PCR 检测。Western blotting检测TLR4蛋白表达水平。然后使用主成分分析 (PCA) 分析 ChTLRs、MyD88、TRIF 和 NF-κB 之间的相关性。结果显示，实验组在25-55天时红髓与白髓界限不清，淋巴细胞数量减少，细胞核破碎溶解。15~45天TLR4 mRNA相对表达量高于对照组，第15天差异极显着（P < 0.01）。实验组TRIF mRNA相对表达量高于对照组。对照组在 25-55 天，实验组NF-κB mRNA相对表达量在15-45天高于对照组。实验组IL-6 mRNA相对表达量在15-45天高于对照组。15-45天实验组TLR4蛋白表达水平高于对照组。PCA结果显示TLR4、TRIF和组分1之间存在很强的相关性。结果表明TLR4在调节缺硒鸡脾脏炎症细胞因子的表达中起重要作用，缺硒可能引起炎症TLR4/TRIF/NF-κB 信号通路对鸡脾脏的损伤。15-45天实验组TLR4蛋白表达水平高于对照组。PCA结果显示TLR4、TRIF和组分1之间存在很强的相关性。结果表明TLR4在调节缺硒鸡脾脏炎症细胞因子的表达中起重要作用，缺硒可能引起炎症TLR4/TRIF/NF-κB 信号通路对鸡脾脏的损伤。15-45天实验组TLR4蛋白表达水平高于对照组。PCA结果显示TLR4、TRIF和组分1之间存在很强的相关性。结果表明TLR4在调节缺硒鸡脾脏炎症细胞因子的表达中起重要作用，缺硒可能引起炎症TLR4/TRIF/NF-κB 信号通路对鸡脾脏的损伤。