Buckham Sporer K R, Burton J L, Earley B, Crowe M A
School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
Vet Immunol Immunopathol. 2007 Jul 15;118(1-2):19-29. doi: 10.1016/j.vetimm.2007.04.002. Epub 2007 Apr 8.
The transportation of beef cattle results in a stress response that is associated with increased susceptibility and severity of respiratory diseases, presumably due to an alteration in immune function. Neutrophils are phagocytic immune cells important in lung defense and are also targets of the stress response. The objective of this study was to determine if a 9h transportation of young bulls by road induced changes in the expression of candidate genes known to be important in neutrophil-mediated defense and inflammation in the lung. These neutrophil genes encompassed functions of apoptosis (A1 and Fas), tissue remodeling (MMP-9), vascular margination (L-selectin), bacterial killing (BPI), and wound healing (betaglycan), as well as responsiveness of the cells to stress-induced increases in glucocorticoid hormones (GRalpha). To explore gene expression changes, blood was collected, plasma harvested, and neutrophils isolated from six Belgian Blue x Friesian bulls (231+/-7.0 kg in weight; 282+/-4 days of age) at -24, 0, 4.5, 9.75, 14.25, 24, and 48h relative to commencement of a 9h road transportation by truck. Plasma cortisol concentrations were elevated at 4.5 and 9.75h, peaking at 50.64+/-4.46 ng/mL (P<0.0001) and confirming that the animals experienced stress. Blood neutrophil count was elevated between 4.5 and 14.25h (P<0.0001), reaching a peak that was over 3-fold higher than the -24h concentration. Neutrophil Fas gene expression was acutely down-regulated (P=0.02) by transportation stress, while expressions of MMP-9, l-selectin, and BPI were profoundly up-regulated (P=0.003, 0.002, and <0.001 respectively). However, no changes in neutrophil expressions of betaglycan, GRalpha, and A1 were detected. It is concluded that a 9h transportation of young bulls induces a gene expression signature in blood neutrophils that increases their circulating numbers and may enhance their pro-inflammatory and anti-bacterial potential.
肉牛运输会引发应激反应，这与呼吸道疾病易感性增加及病情加重相关，推测是由于免疫功能改变所致。中性粒细胞是肺部防御中重要的吞噬免疫细胞，也是应激反应的靶点。本研究的目的是确定用公路运输年轻公牛9小时是否会引起已知在中性粒细胞介导的肺部防御和炎症中起重要作用的候选基因表达的变化。这些中性粒细胞基因涵盖凋亡（A1和Fas）、组织重塑（基质金属蛋白酶-9，MMP-9）、血管边缘化（L-选择素）、细菌杀伤（杀菌/通透性增加蛋白，BPI）和伤口愈合（β-聚糖）功能，以及细胞对应激诱导的糖皮质激素增加的反应性（糖皮质激素受体α，GRα）。为探究基因表达变化，在相对于用卡车进行9小时公路运输开始的-24、0、4.5、9.75、14.25、24和48小时，从6头比利时蓝牛×弗里斯兰公牛（体重231±7.0千克；年龄282±4天）采集血液、收获血浆并分离中性粒细胞。血浆皮质醇浓度在4.5和9.75小时升高，峰值为50.64±4.46纳克/毫升（P<0.0001），证实动物经历了应激。血液中性粒细胞计数在4.5至14.25小时之间升高（P<0.0001），达到的峰值比-24小时浓度高出3倍以上。中性粒细胞Fas基因表达因运输应激而急性下调（P=0.02），而MMP-9、L-选择素和BPI的表达则显著上调（分别为P=0.003、0.002和<0.001）。然而，未检测到中性粒细胞β-聚糖、GRα和A1表达的变化。得出的结论是，年轻公牛9小时的运输会在血液中性粒细胞中诱导一种基因表达特征，增加其循环数量，并可能增强其促炎和抗菌潜力。
