PDF(Pubmed)
Abstract：
In the first study, an in vitro culture system was developed to investigate the effects of carnosine on macrophage proinflammatory cytokine response using an established chicken macrophage cell line (CMC), gut integrity using a chicken intestinal epithelial cell line (IEC), muscle differentiation in quail muscle cells (QMCs) and primary chicken embryonic muscle cells (PMCs), and direct anti-parasitic effect against Eimeria maxima sporozoites. Cells to be tested were seeded in 24-well plates and treated with carnosine at 4 different concentrations (0.1, 1.0, and 10.0 µg). After 18 h of incubation, cells were harvested to measure gene expression of proinflammatory cytokines in CMC, tight junction (TJ) proteins in IECs, and muscle cell growth markers in QMCs and PMCs. In vivo trials were conducted to investigate the effect of dietary carnosine on disease parameters in broiler chickens challenged with E. maxima. One hundred and twenty male broiler chickens (0-day-old) were allocated into 4 treatment groups: 1) basal diet without infection (NC), 2) basal diet with E. maxima infection (PC), 3) carnosine at 10.0 mg/kg feed with PC (HCS), and 4) carnosine at 1.0 mg/kg feed with PC (LCS). All groups except NC were orally infected with E. maxima on d 14. Jejunal samples were collected for lesion scoring and jejunum gut tissues were used for transcriptomic analysis of cytokines and TJ proteins. In vitro, carnosine treatment significantly decreased IL-1β gene expression in CMC following LPS stimulation. In vivo feeding studies showed that dietary carnosine increased BW and ADG of chickens in E. maxima-infected groups and reduced the jejunal lesion score and fecal oocyst shedding in HCS group. Jejunal IL-1β, IL-8, and IFN-γ expression were suppressed in the HCS group compared to PC. The expression levels of claudin-1 and occludin in IECs were also increased in HCS following carnosine treatment. In conclusion, these findings highlight the beneficial effects of dietary carnosine supplementation on intestinal immune responses and gut barrier function in broiler chickens exposed to E. maxima infection.
摘要：
在第一项研究中，使用已建立的鸡巨噬细胞系（CMC），开发了一种体外培养系统来研究肌肽对巨噬细胞促炎细胞因子反应的影响，使用鸡肠上皮细胞系（IEC）的肠道完整性，鹌鹑肌细胞（QMC）和原代鸡胚肌细胞（PMC）的肌肉分化，和直接抗寄生虫作用的艾美球虫子孢子。将待测试的细胞接种在24孔板中，并用4种不同浓度（0.1、1.0和10.0μg）的肌肽处理。孵育18小时后，收集细胞以测量CMC中促炎细胞因子的基因表达，IEC中的紧密连接（TJ）蛋白，以及QMC和PMC中的肌肉细胞生长标记。进行体内试验以研究膳食肌肽对用E.maxima攻击的肉鸡的疾病参数的影响。将120只雄性肉鸡（0日龄）分为4个处理组：1）无感染的基础饮食（NC），2）基础饮食与E.maxima感染（PC），3）含PC（HCS）的10.0mg/kg饲料的肌肽，和4)含PC(LCS)的1.0mg/kg的肌肽。除NC外，所有组均在第14天口服感染E.maxima。收集空肠样品用于损伤评分,空肠组织用于细胞因子和TJ蛋白的转录组学分析。体外，LPS刺激后，肌肽处理显着降低了CMC中IL-1β基因的表达。体内饲喂研究表明，饮食肌肽增加了E.maxima感染组的鸡的BW和ADG，并降低了HCS组的空肠病变评分和粪便卵囊脱落。空肠IL-1β,与PC相比，HCS组的IL-8和IFN-γ表达受到抑制。claudin-1和occludin在IEC中的表达水平在肌肽处理后在HCS中也增加。总之,这些发现强调了膳食肌肽补充对暴露于E.maxima感染的肉鸡肠道免疫反应和肠道屏障功能的有益影响。
