Ju Zhihua, Jiang Qiang, Liu Gang, Wang Xiuge, Luo Guojing, Zhang Yan, Zhang Jibin, Zhong Jifeng, Huang Jinming
Dairy Cattle Research Center, Shandong Academy of Agricultural Sciences, No. 159 North of Industry Road, Jinan, Shandong, 250131, China.
National Center for Preservation and Utilization of Genetic Resources of Domestic Animals, National Animal Husbandry Service, Beijing, 100193, China.
Anim Genet. 2018 Feb;49(1):3-18. doi: 10.1111/age.12628. Epub 2018 Jan 8.
Identification of microRNAs (miRNAs), target genes and regulatory networks associated with innate immune and inflammatory responses and tissue damage is essential to elucidate the molecular and genetic mechanisms for resistance to mastitis. In this study, a combination of Solexa sequencing and custom miRNA chip approaches was used to profile the expression of miRNAs in bovine mammary gland at the late stage of natural infection with Staphylococcus aureus, a widespread mastitis pathogen. We found 383 loci corresponding to 277 known and 49 putative novel miRNAs, two potential mitrons and 266 differentially expressed miRNAs in the healthy and mastitic cows' mammary glands. Several interaction networks and regulators involved in mastitis susceptibility, such as ALCAM, COL1A1, APOP4, ITIH4, CRP and fibrinogen alpha (FGA), were highlighted. Significant down-regulation and location of bta-miR-26a, which targets FGA in the mastitic mammary glands, were validated using quantitative real-time PCR, in situ hybridization and dual-luciferase reporter assays. We propose that the observed miRNA variations in mammary glands of mastitic cows are related to the maintenance of immune and defense responses, cell proliferation and apoptosis, and tissue injury and healing during the late stage of infection. Furthermore, the effect of bta-miR-26a in mastitis, mediated at least in part by enhancing FGA expression, involves host defense, inflammation and tissue damage.
鉴定与先天性免疫、炎症反应及组织损伤相关的微小RNA（miRNA）、靶基因和调控网络，对于阐明乳腺炎抗性的分子和遗传机制至关重要。在本研究中，采用Solexa测序和定制miRNA芯片相结合的方法，对金黄色葡萄球菌（一种广泛传播的乳腺炎病原体）自然感染后期奶牛乳腺中miRNA的表达进行了分析。我们在健康和患乳腺炎奶牛的乳腺中发现了383个位点，对应277个已知的和49个假定的新miRNA、两个潜在的线粒体RNA和266个差异表达的miRNA。突出了几个与乳腺炎易感性相关的相互作用网络和调节因子，如活化白细胞黏附分子（ALCAM）、Ⅰ型胶原α1链（COL1A1）、载脂蛋白4（APOP4）、富含亮氨酸α2-糖蛋白4（ITIH4）、C反应蛋白（CRP）和纤维蛋白原α链（FGA）。利用定量实时PCR、原位杂交和双荧光素酶报告基因检测，验证了患乳腺炎乳腺中靶向FGA的bta-miR-26a的显著下调及其定位。我们认为，在患乳腺炎奶牛乳腺中观察到的miRNA变化与感染后期免疫和防御反应的维持、细胞增殖和凋亡以及组织损伤和愈合有关。此外，bta-miR-26a在乳腺炎中的作用，至少部分是通过增强FGA表达介导的，涉及宿主防御、炎症和组织损伤。
