Liyanage T D, Nikapitiya Chamilani, Lee Jehee, De Zoysa Mahanama
College of Veterinary Medicine, Chungnam National University, Yuseong-gu Daejeon, 34134, Republic of Korea.
Department of Marine Life Sciences, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea.
Fish Shellfish Immunol. 2020 Nov;106:898-909. doi: 10.1016/j.fsi.2020.08.045. Epub 2020 Sep 2.
MicroRNAs (miRNAs) constitute a group of small non-coding RNAs (~22 nucleotides) and one of their main functions is to regulate the immune responses. Gram-positive bacterium, Streptococcus parauberis is the main causative agent of "Streptococcosis" in wide range of fish species. In this study, we performed high throughput sequencing analysis to identify the miRNA profile against S. parauberis infection in the spleen of zebrafish (Danio rerio). Overall, 349 known and 151 novel miRNAs were discovered. Among them, 12 known miRNAs (dre-miR-34b, dre-miR-135a, dre-miR-200b-5p, dre-miR-146b, dre-miR-31, dre-miR-17a-3p, dre-miR-222a-3p, dre-miR-731, dre-miR-301b-3p and dre-miR-30a-3p) and 9 novel miRNAs were differentially expressed (DE) in the spleen of S. parauberis challenged zebrafish. The identified 12 DE miRNAs were predicted to regulate 721 target genes. We confirmed the miRNA expression results by validating selected known and novel DE miRNAs using qRT-PCR. Gene Ontology (GO), Kyoto Encyclopedia of Genes (KEGG) pathway analysis and miRNA-mRNA interactions implies that specific target genes of DE miRNAs are associated with immune responses. The enriched pathways included Toll-like receptor (TLR), C-type lectin, NOD-like receptor, and RIG-I-like receptor signaling pathways, etc. Especially, dre-miR-200b-5p, dre-miR-146b, dre-miR-731, dre-miR-222a-3p, and dre-miR-34b were able to target potential immune-related genes such as il10, irak1, traf6, hspa8 and ikbke upon S. parauberis challenge. Thus, overall results could lay a foundation to understand the underlying immune regulatory role of miRNAs in response to pathogenic S. parauberis infection in teleosts.
微小RNA（miRNA）是一组小的非编码RNA（约22个核苷酸），其主要功能之一是调节免疫反应。革兰氏阳性菌副乳房链球菌是多种鱼类“链球菌病”的主要病原体。在本研究中，我们进行了高通量测序分析，以鉴定斑马鱼（Danio rerio）脾脏中针对副乳房链球菌感染的miRNA谱。总体而言，共发现了349个已知miRNA和151个新miRNA。其中，12个已知miRNA（dre-miR-34b、dre-miR-135a、dre-miR-200b-5p、dre-miR-146b、dre-miR-31、dre-miR-17a-3p、dre-miR-222a-3p、dre-miR-731、dre-miR-301b-3p和dre-miR-30a-3p）和9个新miRNA在副乳房链球菌攻击的斑马鱼脾脏中差异表达（DE）。鉴定出的12个DE miRNA预计可调节721个靶基因。我们通过使用qRT-PCR验证选定的已知和新的DE miRNA来确认miRNA表达结果。基因本体论（GO）、京都基因与基因组百科全书（KEGG）途径分析以及miRNA-mRNA相互作用表明，DE miRNA的特定靶基因与免疫反应相关。富集的途径包括Toll样受体（TLR）、C型凝集素、NOD样受体和RIG-I样受体信号通路等。特别是，在副乳房链球菌攻击后，dre-miR-200b-5p、dre-miR-146b、dre-miR-731、dre-miR-222a-3p和dre-miR-34b能够靶向潜在的免疫相关基因，如il10、irak1、traf6、hspa8和ikbke。因此，总体结果可为理解miRNA在硬骨鱼应对致病性副乳房链球菌感染时的潜在免疫调节作用奠定基础。
