Institute of Veterinary Biochemistry, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, Germany.
Reprod Biol Endocrinol. 2010 Dec 22;8:152. doi: 10.1186/1477-7827-8-152.
Inflammatory processes and infections of the uterine wall must be accepted as a physiological event in dairy cows after calving. This might result in clinical or subclinical endometritis which is assumed to impair reproductive performance in the current lactation. Several cytokines and acute phase proteins have been discussed as local and systemic mediators of these inflammatory processes. The aim of the present study was to investigate the endometrial mRNA expression of the chemokine CXC ligand 5 (CXCL5), interleukin 1β (IL1B), IL6, IL8, tumour necrosis factor alpha (TNF), prostaglandin-endoperoxide synthase 2 (PTGS2) and haptoglobin (HP) in the postpartum period.
Endometrial samples were obtained from primiparous cows (n = 5) on days 10, 17, 24, 31, 38 and 45 postpartum (pp) using the cytobrush technique. Cytological smears were prepared from cytobrush samples to determine the proportion of polymorphonuclear neutrophils (PMN). Total RNA was extracted from endometrial samples, and real-time RT-PCR was performed.
A time-dependent mRNA expression of the investigated factors was found for the course of the postpartum period. In detail, a significantly higher expression of these factors was observed on day 17 pp compared to day 31 pp. Furthermore, the proportion of PMN peaked between days 10-24 pp and decreased thereafter to low percentages (< 5%) on day 31 pp and thereafter. In addition, CXCL5, IL1B, IL8 and HP mRNA expression correlated significantly with the proportion of PMN (P < 0.05). A significantly higher CXCL5, IL1B, IL6, IL8, PTGS2 and TNF mRNA content was observed in samples from cows with an inflamed endometrium compared with samples from cows with a healthy endometrium (P < 0.05).
These results show that inflammatory cytokines and acute phase proteins are expressed in the bovine endometrium in a time-related manner during the postpartum period, with a significant expression peak on day 17 pp as a possible mucosal immune response in the uterus. The evaluation of the expression patterns of such candidate genes may reveal more information than only determining the percentage of PMN to judge the severity of an inflammation.
在奶牛产后，子宫壁的炎症过程和感染必须被认为是一种生理现象。这可能导致临床或亚临床子宫内膜炎，从而损害当前泌乳期的繁殖性能。几种细胞因子和急性期蛋白被认为是这些炎症过程的局部和全身介质。本研究的目的是调查产后时期趋化因子 CXC 配体 5（CXCL5）、白细胞介素 1β（IL1B）、IL6、IL8、肿瘤坏死因子α（TNF）、前列腺素内过氧化物合酶 2（PTGS2）和触珠蛋白（HP）在内膜中的 mRNA 表达。
使用细胞刷技术从初产奶牛（n=5）产后第 10、17、24、31、38 和 45 天采集子宫内膜样本。从细胞刷样本中制备细胞学涂片，以确定多形核中性粒细胞（PMN）的比例。从子宫内膜样本中提取总 RNA，并进行实时 RT-PCR。
在产后期间，研究因素的 mRNA 表达呈现时间依赖性。具体而言，与第 31 天相比，第 17 天这些因素的表达明显更高。此外，PMN 的比例在第 10-24 天之间达到峰值，然后下降，在第 31 天降至低百分比（<5%），之后保持较低水平。此外，CXCL5、IL1B、IL8 和 HP mRNA 表达与PMN 比例显著相关（P<0.05）。与健康子宫内膜的样本相比，患有子宫内膜炎的奶牛样本中 CXCL5、IL1B、IL6、IL8、PTGS2 和 TNF mRNA 含量显著更高（P<0.05）。
这些结果表明，在产后期间，炎症细胞因子和急性期蛋白在内膜中以时间相关的方式表达，在第 17 天达到显著表达高峰，这可能是子宫中的黏膜免疫反应。评估这些候选基因的表达模式可能比仅确定PMN 的百分比来判断炎症的严重程度提供更多信息。
