Liang Guanxiang, Malmuthuge Nilusha, Guan Yongjuan, Ren Yuwei, Griebel Philip J, Guan Le Luo
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
UWA Institute of Agriculture and School of Animal Biology, University of Western Australia, Crawley, WA, Australia.
Sci Rep. 2016 Apr 22;6:24964. doi: 10.1038/srep24964.
The molecular regulatory mechanisms of host responses to Mycobacterium avium subsp. paratuberculosis (MAP) infection during the early subclinical stage are still not clear. In this study, surgically isolated ileal segments in newborn calves (n = 5) were used to establish in vivo MAP infection adjacent to an uninfected control intestinal compartment. RNA-Seq was used to profile the whole transcriptome (mRNAs) and the microRNAome (miRNAs) of ileal tissues collected at one-month post-infection. The most related function of the differentially expressed mRNAs between infected and uninfected tissues was "proliferation of endothelial cells", indicating that MAP infection may lead to the over-proliferation of endothelial cells. In addition, 46.2% of detected mRNAs displayed alternative splicing events. The pre-mRNA of two genes related to macrophage maturation (monocyte to macrophage differentiation-associated) and lysosome function (adenosine deaminase) showed differential alternative splicing events, suggesting that specific changes in the pre-mRNA splicing sites may be a mechanism by which MAP escapes host immune responses. Moreover, 9 miRNAs were differentially expressed after MAP infection. The integrated analysis of microRNAome and transcriptome revealed that these miRNAs might regulate host responses to MAP infection, such as "proliferation of endothelial cells" (bta-miR-196 b), "bacteria recognition" (bta-miR-146 b), and "regulation of the inflammatory response" (bta-miR-146 b).
宿主对副结核分枝杆菌（MAP）感染在亚临床早期阶段的分子调控机制仍不清楚。在本研究中，使用新生犊牛（n = 5）手术分离的回肠段在未感染的对照肠腔附近建立体内MAP感染。RNA测序用于分析感染后1个月收集的回肠组织的全转录组（mRNA）和微小RNA组（miRNA）。感染组织与未感染组织之间差异表达的mRNA最相关的功能是“内皮细胞增殖”，表明MAP感染可能导致内皮细胞过度增殖。此外，46.2%检测到的mRNA显示出可变剪接事件。与巨噬细胞成熟（单核细胞向巨噬细胞分化相关）和溶酶体功能（腺苷脱氨酶）相关的两个基因的前体mRNA显示出差异可变剪接事件，表明前体mRNA剪接位点的特定变化可能是MAP逃避宿主免疫反应的一种机制。此外，MAP感染后有9种miRNA差异表达。微小RNA组和转录组的综合分析表明，这些miRNA可能调节宿主对MAP感染的反应，如“内皮细胞增殖”（bta-miR-196 b）、“细菌识别”（bta-miR-14 6 b）和“炎症反应调节”（bta-miR-146 b）。
