Key Laboratory of Animal Nutrition and Feed Science in East China, Ministry of Agriculture, College of Animal Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
Biol Trace Elem Res. 2018 Jul;184(1):92-98. doi: 10.1007/s12011-017-1174-0. Epub 2017 Oct 10.
The study was conducted to investigate the effect of chitosan-zinc chelate (CS-Zn) on TLR4-NF-κB signaling pathway and cell death-associated proteins in a weanling pig model. A total of 90 weaned piglets were allotted to three dietary treatments (the dietary treatments were as follows: (1) experimental diet with supplemental ZnSO (150 mg Zn/kg diet), (2) experimental diet with supplemental CS-Zn (150 mg Zn/kg diet), and (3) experimental diet with a supplemental mixture of chitosan and ZnSO (150 mg/kg Zn; the content of chitosan was equal to CS-Zn, which is according to molar basis)). The feeding trial lasted 30 days. The results showed that compared with ZnSO or CS+ZnSO, CS-Zn decreased the expressions of the cell death-associated proteins Beclin-1, and Cleaved-Caspase3 and the ratio of LC3II/LC3I. The intestinal expressions of TLR4 and its downstream signals NF-κB, IKKβ, and IκBα were down-regulated simultaneously. Moreover, the contents of pro-inflammatory cytokines IL-2, TNF-α, and IFN-γ were decreased. The results indicated that as organic zinc source, CS-Zn was more effective than ZnSO and the mixture of chitosan and ZnSO for inhibiting inflammatory response and decreasing the expressions of proteins associated with cell death. The great anti-inflammatory effect of CS-Zn was modulated by inhibiting the TLR4-NF-κB signaling pathway, and the effect of CS-Zn on down-regulating the expression of cell death-associated proteins might also closely be associated with the TLR4-NF-κB signaling pathway.
本研究旨在探讨壳聚糖-锌螯合物（CS-Zn）对断奶仔猪模型 TLR4-NF-κB 信号通路和细胞死亡相关蛋白的影响。将 90 头断奶仔猪分为 3 种饲粮处理组（饲粮处理如下：（1）补充 ZnSO4（饲粮中 150 mg Zn/kg）的实验饲粮，（2）补充 CS-Zn（饲粮中 150 mg Zn/kg）的实验饲粮，（3）补充壳聚糖和 ZnSO4混合物（饲粮中 150 mg/kg Zn；壳聚糖含量与 CS-Zn 相等，这是基于摩尔基础）的实验饲粮）。饲养试验持续 30 天。结果表明，与 ZnSO4 或 CS+ZnSO4 相比，CS-Zn 降低了细胞死亡相关蛋白 Beclin-1 和 Cleaved-Caspase3 的表达以及 LC3II/LC3I 的比值。肠道 TLR4 及其下游信号 NF-κB、IKKβ 和 IκBα 的表达也同时下调。此外，促炎细胞因子 IL-2、TNF-α 和 IFN-γ 的含量也降低。结果表明，作为有机锌源，CS-Zn 比 ZnSO4 和壳聚糖与 ZnSO4 的混合物更能有效抑制炎症反应和降低与细胞死亡相关蛋白的表达。CS-Zn 的强大抗炎作用是通过抑制 TLR4-NF-κB 信号通路来调节的，CS-Zn 下调细胞死亡相关蛋白表达的作用可能也与 TLR4-NF-κB 信号通路密切相关。
