奶牛乳汁外泌体中乳房炎抗性相关microRNA的筛选与功能分析

Screening and functional analysis of microRNAs related to mastitis resistance in milk exosomes of dairy cows

奶牛乳汁外泌体中的microRNA(miRNA)在乳腺癌、炎症和其他乳腺疾病发生时起着关键的调控作用,为了解及分析乳汁外泌体中可能存在的参与奶牛乳房炎抗性的miRNA,以健康牛及乳房炎奶牛乳腺组织差异表达miRNA为背景,结合目前已知的奶牛乳汁外泌体miRNA,利用Targetscan、miRDB、miRanda、Vesiclepedia、DAVID等生物信息学分析系统及数据库系统,筛选奶牛乳汁外泌体中可能参与奶牛乳房炎抗性的miRNA,并对其序列保守性、候选靶基因及靶基因参与的调控功能通路等进行预测与分析。结果表明,健康奶牛与乳房炎奶牛乳腺组织中存在显著表达差异的miRNA 29个;Vesiclepedia数据库和NCBI检索文献共获得奶牛乳汁外泌体中的miRNA 66个,其中miR-223、miR-125b、miR-378b在两数据中共存,并在人与奶牛及其他哺乳动物之间高度保守。候选靶基因的KEGG功能通路分析显示,MAPK,p53、PI3K-Akt及miRNA的癌症作用、内质网蛋白加工、溶酶体和细胞凋亡等通路均被显著富集。表明外泌体中存在的3个miRNA对奶牛乳房炎发生时的炎症反应及免疫应答均可起重要调控作用,但其具体分子机制仍有待进一步验证。研究结果可为奶牛乳房炎分子辅助选择标记的筛选以及跨物种机体免疫调控的影响因素及作用机制研究提供参考。

MicroRNA(miRNA) in dairy cow exosome plays a key regulatory role in the development of breast cancer,inflammation and other breast diseases.In order to understand and analyze the possible miRNAs involved in milk mastitis in dairy cow mastitis,the differentially expressed miRNAs between healthy cow and mastitis cow mammary gland were taken as the background,and the currently known dairy milk exosome miRNA was utilized as well in this study.Then,the bioinformatics database system such as Targetscan,miRDB,miRanda,Vesiclepedia,DAVID were used to screen miRNAs in dairy cow exosome that may be involved in cow mastitis resistance,and to analyze the conserved sequences,predicate candidate target genes and their regulatory pathways involved in target genes.The results showed that there are 29 miRNAs differed significantly between healthy dairy cows and mastitis cows.Thus,in milk exosomes,the number of miRNAs that summarized according to the Vesiclepedia database and the NCBI is 66.Among them,miR-223,miR-125 band miR-378 bare present in both two miRNA group,which are highly conservative between human,cows and other mammal.Furthermore,the KEGG signaling pathway showed that the candidate target genes of three miRNAs are mainly enriched on the signaling pathway of MAPK,PI3 K-Akt signaling pathway,miRNAs in cancer,protein processing in endoplasmic reticulum,lysosome,apoptosis.etc.These indicated that the screened three miRNAs present in exosomes can play an important regulatory role in the inflammatory response and immune response in cow mastitis,but the specific molecular mechanism remains to be further verified.Collectively,the results can provide reference for the screening of molecular assisted selection markers for dairy cow mastitis and facilitate to study the influencing factors and mechanism of immune regulation across species.