The expression profile of Aedes albopictus miRNAs is altered by dengue virus serotype-2 infection

Background: Aedes albopictus is an important vector of Dengue virus (DENV) and it has quickly invaded the tropical and temperate environments worldwide. A few studies have shown that, microRNAs (miRNAs) regulate mosquito defense against pathogens. However, there is no systematic analysis of the impact of DENV infection on miRNA expression in Ae. albopictus. We conducted this study to investigate the miRNA expression of Ae. albopictus upon DENV-2 infection using Illumina RNA sequencing. Results: A total of 103 known and 5 novel candidate miRNAs were identified in DENV-2 infected and non-infected adult female Ae. albopictus. Comparative analysis indicated that 52 miRNAs were significantly down-regulated and 18 were up-regulated significantly after infection. Furthermore, RT-qPCR validated the expression patterns of eleven of these differentially expressed miRNAs. Targets prediction and functional analysis of these regulated miRNAs suggested that miR-34-5p and miR-87 might be involved in the anti-pathogen and immune responses. Conclusion: This is the first systematic study on the impact of DENV infection on miRNA expression in Ae. albopictus. Complex changes in miRNA expression suggest a potential role of miRNAs in antiviral responses by regulating immune-related genes. This investigation provides information concerning DENV-induced miRNAs and offers clues for identifying potential candidates for vector based antiviral strategies.