microRNA expression profiling and bioinformatic analysis of dengue virus-infected peripheral blood mononuclear cells

Dengue virus (DENV) causes self-limiting dengue fever (DF), severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). It is generally considered that cytokine storm leads to the increased plasma leakage characteristic of DHF/DSS. In the present study, peripheral blood mononuclear cells (PBMCs) were isolated from blood samples of healthy volunteers and infected with DENV serotype 2 (DENV2). Culture supernatants of DENV2-infected and -uninfected PBMCs were analyzed using a human cytokine array. Between a 6-12 h post-infection, levels of CCL5, IL-6 and IL-8 were markedly elevated, while those of TNF-alpha decreased. Total RNA isolated from these PBMCs was analyzed by human miRNA microarray to identify differentially expressed microRNAs (miRNAs). Quantitative reverse transcription polymerase chain reaction was used to validate 11 upregulated and 4 downregulated miRNAs. Sanger mibase, miRanda and Target Scan were used to identify 261 common predicted genes. Databases were used to identify homologous sequences on mRNAs of putative target genes that may be directly bound by the miRNAs identified. We found that cytokines and epigenetic regulators may be putative target genes of these miRNAs. Using ingenuity pathway analysis, we noted that canonical pathways, including biological regulation, may be modulated by these miRNAs.