Department of Biotechnology and Nutrigenomics, Institute of Genetics and Animal Biotechnology Polish Academy of Sciences, ul Postepu 36A, 05-552, Jastrzębiec, Poland.
Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, ul Ciszewskiego 8, 02-786, Warsaw, Poland.
Vet Res. 2021 Mar 6;52(1):41. doi: 10.1186/s13567-021-00912-2.
MicroRNAs (miRNAs) are short, non-coding RNAs, 21-23 nucleotides in length which are known to regulate biological processes that greatly impact immune system activity. The aim of the study was to compare the miRNA expression in non-infected (H) mammary gland parenchyma samples with that of glands infected with coagulase-positive staphylococci (CoPS) or coagulase-negative staphylococci (CoNS) using next-generation sequencing. The miRNA profile of the parenchyma was found to change during mastitis, with its profile depending on the type of pathogen. Comparing the CoPS and H groups, 256 known and 260 potentially new miRNAs were identified, including 32 that were differentially expressed (p ≤ 0.05), of which 27 were upregulated and 5 downregulated. Comparing the CoNS and H groups, 242 known and 171 new unique miRNAs were identified: 10 were upregulated (p ≤ 0.05), and 2 downregulated (p ≤ 0.05). In addition, comparing CoPS with H and CoNS with H, 5 Kyoto Encyclopedia of Genes and Genomes pathways were identified; in both comparisons, differentially-expressed miRNAs were associated with the bacterial invasion of epithelial cells and focal adhesion pathways. Four gene ontology terms were identified in each comparison, with 2 being common to both immune system processes and signal transduction. Our results indicate that miRNAs, especially miR-99 and miR-182, play an essential role in the epigenetic regulation of a range of cellular processes, including immunological systems bacterial growth in dendritic cells and disease pathogenesis (miR-99), DNA repair and tumor progression (miR-182).
微小 RNA（miRNA）是 21-23 个核苷酸长的短非编码 RNA，已知它们可以调节对免疫系统活动影响很大的生物过程。本研究的目的是使用下一代测序比较未感染（H）乳腺实质样本与感染凝固酶阳性葡萄球菌（CoPS）或凝固酶阴性葡萄球菌（CoNS）的腺体之间的 miRNA 表达。发现乳腺炎期间实质的 miRNA 谱发生变化，其谱取决于病原体的类型。比较 CoPS 和 H 组，鉴定出 256 个已知和 260 个潜在新的 miRNA，其中 32 个差异表达（p≤0.05），其中 27 个上调，5 个下调。比较 CoNS 和 H 组，鉴定出 242 个已知和 171 个新的独特 miRNA：10 个上调（p≤0.05），2 个下调（p≤0.05）。此外，比较 CoPS 与 H 和 CoNS 与 H，鉴定出 5 个京都基因与基因组百科全书通路；在这两种比较中，差异表达的 miRNA 与上皮细胞和焦点附着途径的细菌入侵有关。在每种比较中都鉴定出 4 个基因本体术语，其中 2 个与免疫系统过程和信号转导有关。我们的结果表明，miRNA，尤其是 miR-99 和 miR-182，在一系列细胞过程的表观遗传调控中发挥着重要作用，包括免疫和细菌在树突细胞中的生长以及疾病发病机制（miR-99）、DNA 修复和肿瘤进展（miR-182）。
