Abascal-Ponciano Gerardo A, Leiva Samuel F, Flees Joshua J, Avila Luis P, Starkey Jessica D, Starkey Charles W
Department of Poultry Science, Auburn University, Auburn, AL, United States.
Front Vet Sci. 2022 Jul 11;9:947276. doi: 10.3389/fvets.2022.947276. eCollection 2022.
Vitamin D signaling is important for intestinal homeostasis. An increase in vitamin D receptors in immune cells can modulate cell phenotype and cytokine secretion. Cytokines regulate both pro- (interleukin 17; IL-17) and anti-inflammatory (IL-10) responses triggered by external stimuli. Inflammation in intestinal tissues can disrupt the structure and the remodeling of epithelial tight junction complexes, thus, compromising the protective barrier. The objective of the study was to determine the impact of dietary supplementation with 25-hydroxycholecalciferol (OHD), a hydroxylated metabolite of vitamin D, on intestinal cytokine abundance and epithelial barrier integrity over time in broilers. A randomized complete block design experiment was conducted to evaluate the effect of dietary OHD inclusion on relative protein expression of the cytokines, IL-17 and IL-10, and tight junction proteins, Zona Occludens 1 (ZO-1), and Claudin-1 (CLD-1), in broiler chicken duodenum and ileum from 3 to 21 days post-hatch. On day 0, male chicks ( = 168) were randomly assigned to raised floor pens. Experimental corn-soybean meal-based treatments were as follows: (1) a common starter diet containing 5,000 IU of D per kg of feed (VITD) and (2) a common starter diet containing 2,240 IU of D + 2,760 IU of OHD per kg of feed (OHD) fed from days 0 to 21. On days 3, 6, 9, 12, 15, 18, and 21, 12 birds per treatment were euthanized to collect tissue samples for quantitative, multiplex, and fluorescent Western blot analysis. Target proteins were quantified using Image Quant TL 8.1 and expressed relative to total protein. Feeding OHD post-hatch decreased ileal IL-10 (anti-inflammatory) protein expression in 21-day-old broilers compared with VITD only ( = 0.0190). Broilers fed only VITD post-hatch had greater IL-17 (pro-inflammatory) protein expression in the ileum at 18 and 21 days-of-age ( = 0.0412) than those that fed OHD. Dietary inclusion of OHD lowered the abundance of key inflammatory cytokines in the ileum of young broilers.
维生素D信号传导对肠道稳态很重要。免疫细胞中维生素D受体的增加可调节细胞表型和细胞因子分泌。细胞因子调节由外部刺激引发的促炎（白细胞介素17；IL-17）和抗炎（IL-10）反应。肠道组织中的炎症会破坏上皮紧密连接复合体的结构和重塑，从而损害保护屏障。本研究的目的是确定日粮中添加维生素D的羟基化代谢产物25-羟基胆钙化醇（OHD）对肉鸡肠道细胞因子丰度和上皮屏障完整性随时间的影响。进行了一项随机完全区组设计实验，以评估日粮中添加OHD对雏鸡出壳后3至21天十二指肠和回肠中细胞因子IL-17和IL-10以及紧密连接蛋白闭锁小带蛋白1（ZO-1）和闭合蛋白1（CLD-1）相对蛋白表达的影响。在第0天，将雄性雏鸡（n = 168）随机分配到地面饲养栏中。基于玉米-豆粕的实验处理如下：（1）每千克饲料含5000 IU维生素D的普通开食料（VITD）和（2）每千克饲料含2240 IU维生素D + 2760 IU OHD的普通开食料（OHD），从第0天到第21天饲喂。在第3、6、9、12、15、18和21天，每个处理处死12只鸡，收集组织样本进行定量、多重和荧光蛋白质印迹分析。使用Image Quant TL 8.1对目标蛋白进行定量，并相对于总蛋白表达。与仅饲喂VITD的肉鸡相比，出壳后饲喂OHD的21日龄肉鸡回肠中IL-10（抗炎）蛋白表达降低（P = 0.0190）。出壳后仅饲喂VITD的肉鸡在18和21日龄时回肠中IL-17（促炎）蛋白表达高于饲喂OHD的肉鸡（P = 0.0412）。日粮中添加OHD可降低幼龄肉鸡回肠中关键炎性细胞因子的丰度。
