Abstract

Background: Pathogenesis of dengue infection is not fully understood. Recently, the role of microRNA, which is overexpressed in the serum or immune cell of dengue infected patients has been related with the cytokine storm which leads to leakage of plasma in endothelial cells. The objective of our study was to determine whether particular microRNA is overexpressed in PBMCs infected with DENV, and to assess its correlation to the expression of suppressor of cytokine signaling 3 (SOCS3 and SOCS1) proteins in order to increase the production of pro-inflammatory cytokines. Herein, we report the result of a preliminary study on the expression of microRNA hsa-let-7e.

Methods: The peripheral blood mononuclear cells (PBMCs) from the healthy volunteer were isolated by Ficoll density gradient centrifugation and infected with clinical isolate of DENV-2. RNA was extracted with miRCURY LNA^TM Exiqon. Quantitative Real-Time PCR was used to measure the relative expression of hsa-let-7e micro RNA and the mRNA of SOCS1 and SOCS3 proteins.

Results: MicroRNA hsa-let-7e expression was increased in PBMCs upon DENV-2 infection. The relative expression of hsa-let-7e is detected at 1.46 folds relative to uninfected PBMCs in 4 hours post-infection and decreased in 19 hours post infection. In contrast, the expression of mRNA of SOCS3 was inversely expressed with hsa-let-7 expression.

Conclusion: MicroRNA was overexpressed in PBMCs upon infection with DENV-2. This microRNA may bind the SOCS3 and contribute to the pathogenesis of dengue infection.

Keyword: miRNA; expression; dengue; infection