为研究microRNA在致细胞病变型牛病毒性腹泻病毒(cpBVDV)感染过程中对病毒复制和调控炎症反应的作用机制,本研究以MDBK细胞为模型,通过对cpBVDV感染MDBK前后的总RNA进行microRNA芯片反应,筛选与炎症反应相关的显著差异性microRNA,并预测出其靶基因.通过将miR-2904转染至MDBK细胞,探索其在BVDV感染MDBK细胞过程中的调控作用,并验证其靶基因;利用qRT-PCR检测miR-2904、BVDV 5\'UTR及相关炎症因子mRNA的表达水平,利用Western blot检测靶基因TNFAIP8L2蛋白表达水平.结果 显示,miR-2904是microRNA的候选基因之一,荧光素酶报告结果显示TNFAIP8L2为其潜在的靶基因;炎症反应表明,BVDV感染MDBK细胞后,miR2904的表达水平显著上升(P＜0.05),并且相应下调TNFAIP8L2的表达水平;MDBK细胞转染miR-2904 mimic后,炎症因子COX-2、IL-8、TNFAIP8L2 mRNA以及TNFAIP8L2蛋白的表达水平明显升高(P＜0.05);MDBK细胞接种BVDV后转染miR-2904 mimic,能显著降低BVDV 5\'UTR的表达水平(P＜0.05).结果 表明,miR-2904可以抑制TNFAIP8L2的翻译,增强cpBVDV感染MDBK细胞中的炎症反应以及降低BVDV的复制水平.“,”Bovine viral diarrhoea/mucosal disease (BVD/MD) is caused by bovine viral diarrhea vi-rus (BVDV),which is widespread throughout the world and causes serious harm to livestock.Mi-croRNAs,an endogenous non-coding RNA and a key factor regulating genes at the transcriptional level in organisms,plays an important regulatory role in animals and plants,but its mechanism re-mains unclear.To investigate the regulation mechanism of the key microRNAs on BVDV infections and inflammatory response in MDBK cells,key microRNAs involved with viral infection and in-flammatory responses were screened and identified using MDBK cells infected with BVDV by mi-croRNAs microarray.Results showed that miR-2904 was one of the candidates of key microRNA,and TNFAIP8L2 was identified as its potential target gene by luciferase reporter system.The miR-2904 expression level was validated by qRT-PCR and Western blot.Inflammatory response indica-ted that expression of miR-2904 was induced by the BVDV infection and correspondingly downreg-ulated the expression level of TNFAIP8L2.Additionally miR-2904 could increase the expression level of inflammatory cytokines COX-2,IL-8 and GRO-α mRNA and decrease the level of BVDV replication in MDBK cells.In conclusion,interaction of miR-2904 and TNFAIP8L2 may play an im-portant role in the antivirus activity during the infection process.Overall,we identified the key mi-croRNA involved in the regulation of BVDV infection in MDBK cells,which provides the scientific data for prevention and control of BVDV.