Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
Front Cell Infect Microbiol. 2021 Feb 24;11:634505. doi: 10.3389/fcimb.2021.634505. eCollection 2021.
Cattle have been suggested as the primary reservoirs of O157 mainly as a result of colonization of the recto-anal junction (RAJ) and subsequent shedding into the environment. Although a recent study reported different gene expression at RAJ between super-shedders (SS) and non-shedders (NS), the regulatory mechanisms of altered gene expression is unknown. This study aimed to investigate whether bovine non-coding RNAs play a role in regulating the differentially expressed (DE) genes between SS and NS, thus further influencing O157 shedding behavior in the animals through studying miRNAomes of the whole gastrointestinal tract including duodenum, proximal jejunum, distal jejunum, cecum, spiral colon, descending colon and rectum. The number of miRNAs detected in each intestinal region ranged from 390 ± 13 (duodenum) to 413 ± 49 (descending colon). Comparison between SS and NS revealed the number of differentially expressed (DE) miRNAs ranged from one (in descending colon) to eight (in distal jejunum), and through the whole gut, seven miRNAs were up-regulated and seven were down-regulated in SS. The distal jejunum and rectum were the regions where the most DE miRNAs were identified (eight and seven, respectively). The miRNAs, bta-miR-378b, bta-miR-2284j, and bta-miR-2284d were down-regulated in both distal jejunum and rectum of SS (logfold-change: -2.7 to -3.8), bta-miR-2887 was down-regulated in the rectum of SS (logfold-change: -3.2), and bta-miR-211 and bta-miR-29d-3p were up-regulated in the rectum of SS (logfold-change: 4.5 and 2.2). Functional analysis of these miRNAs indicated their potential regulatory role in host immune functions, including hematological system development and immune cell trafficking. Our findings suggest that altered expression of miRNA in the gut of SS may lead to differential regulation of immune functions involved in O157 super-shedding in cattle.
牛被认为是 O157 的主要储存宿主，主要是因为它们在直肠-肛门交界处（RAJ）定植，并随后将其排入环境中。尽管最近的一项研究报告称，超级脱落者（SS）和非脱落者（NS）之间 RAJ 的基因表达不同，但改变基因表达的调节机制尚不清楚。本研究旨在探讨牛非编码 RNA 是否在调节 SS 和 NS 之间差异表达（DE）基因中发挥作用，从而通过研究包括十二指肠、近端空肠、远端空肠、盲肠、螺旋结肠、降结肠和直肠在内的整个胃肠道的 miRNAome 进一步影响动物中 O157 的脱落行为。在每个肠道区域检测到的 miRNA 数量从 390±13（十二指肠）到 413±49（降结肠）不等。SS 和 NS 之间的比较显示，差异表达（DE）miRNA 的数量从一个（降结肠）到八个（远端空肠）不等，通过整个肠道，SS 中有七个 miRNA 上调，七个 miRNA 下调。在 SS 中，远端空肠和直肠是鉴定出最多 DE miRNA 的区域（分别为 8 个和 7 个）。miRNA bta-miR-378b、bta-miR-2284j 和 bta-miR-2284d 在 SS 的远端空肠和直肠中均下调（logfold-change：-2.7 至-3.8），bta-miR-2887 在 SS 的直肠中下调（logfold-change：-3.2），bta-miR-211 和 bta-miR-29d-3p 在 SS 的直肠中上调（logfold-change：4.5 和 2.2）。这些 miRNA 的功能分析表明，它们在宿主免疫功能中的潜在调节作用，包括血液系统发育和免疫细胞迁移。我们的研究结果表明，SS 肠道中 miRNA 的表达改变可能导致与牛 O157 超级脱落相关的免疫功能的差异调节。
