Natural Resources Institute Finland (Luke), Jokioinen, Finland.
Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.
Vet Res. 2024 Feb 1;55(1):13. doi: 10.1186/s13567-024-01269-y.
Mastitis, inflammation of the mammary gland, is the costliest disease in dairy cattle and a major animal welfare concern. Mastitis is usually caused by bacteria, of which staphylococci, streptococci and Escherichia coli are most frequently isolated from bovine mastitis. Bacteria activate the mammary immune system in variable ways, thereby influencing the severity of the disease. Escherichia coli is a common cause of mastitis in cattle causing both subclinical and clinical mastitis. Understanding of the molecular mechanisms that activate and regulate the host response would be central to effective prevention of mastitis and breeding of cows more resistant to mastitis. We used primary bovine mammary epithelial cell cultures extracted noninvasively from bovine milk samples to monitor the cellular responses to Escherichia coli challenge. Differences in gene expression between control and challenged cells were studied by total RNA-sequencing at two time points post-challenge. In total, 150 and 440 (P < 0.05) differentially expressed genes were identified at 3 h and 24 h post-challenge, respectively. The differentially expressed genes were mostly upregulated at 3 h (141/150) and 24 h (424/440) post-challenge. Our results are in line with known effects of E. coli infection, with a strong early inflammatory response mediated by pathogen receptor families. Among the most significantly enriched early KEGG pathways were the TNF signalling pathway, the cytokine-cytokine receptor interaction, and the NF-kappa B signalling pathway. At 24 h post-challenge, most significantly enriched were the Influenza A, the NOD-like receptor signalling, and the IL-17 signaling pathway.
乳腺炎，即乳腺炎症，是奶牛养殖业中最昂贵的疾病，也是主要的动物福利问题。乳腺炎通常由细菌引起，其中葡萄球菌、链球菌和大肠杆菌最常从牛乳腺炎中分离出来。细菌以不同的方式激活乳腺免疫系统，从而影响疾病的严重程度。大肠杆菌是奶牛乳腺炎的常见病因，可引起亚临床和临床乳腺炎。了解激活和调节宿主反应的分子机制对于有效预防乳腺炎和培育更能抵抗乳腺炎的奶牛至关重要。我们使用从奶牛奶样中无创提取的原代牛乳腺上皮细胞培养物来监测细胞对大肠杆菌攻击的反应。通过在挑战后两个时间点进行总 RNA 测序，研究对照细胞和受挑战细胞之间的基因表达差异。在挑战后 3 小时和 24 小时，分别鉴定出 150 个和 440 个（P<0.05）差异表达基因。差异表达基因在挑战后 3 小时（141/150）和 24 小时（424/440）大多上调。我们的结果与大肠杆菌感染的已知影响一致，具有由病原体受体家族介导的强烈早期炎症反应。在早期最显著富集的 KEGG 途径中，有 TNF 信号通路、细胞因子-细胞因子受体相互作用和 NF-kappa B 信号通路。在挑战后 24 小时，最显著富集的是流感 A、NOD 样受体信号和 IL-17 信号通路。
