Dual downregulation of microRNA 17-5p and E2F1 transcriptional factor in pediatric systemic lupus erythematosus patients

To investigate the relative expression of miRNA 17-5p and one of its target genes E2F1 in peripheral blood of systemic lupus erythematosus SLE pediatric patients. miRNA 17-5p and its target E2F1 miRNA expressions in SLE peripheral blood and controls were analyzed by TaqMan real-time qPCR. Peripheral blood mononuclear cells (PBMCs) of SLE and controls were transfected using a nucleofector device, and E2F1 protein expression was analyzed using luciferase reporter gene assays. Results showed significant downregulation of miRNA 17-5p in SLE patients compared to healthy controls; moreover, miRNA 17-5p was more downregulated in patients on no treatment compared to those on treatment. Relative expression of E2F1, which is target for miRNA 17-5p, was significantly downregulated as well on both miRNA and protein levels in SLE. Our data show an unexpected dual downregulation of both miRNA 17-5p and its target gene E2F1 on the mRNA and protein levels. This may suggest an expression pattern of miRNA 17-5p and its target E2F1 that may be specific to SLE.