Figure 3

Promoter binding of STAT3 transactivates miR-17 ~ 92 gene to increase mature miR-17 ~ 92 miRNAs expression following Toxoplasma infection. (A) Western blot analysis showing stable knock-down of STAT3 by siRNA. (B) STAT3-dependent upregulation of pri-miR-17 ~ 92 in human macrophage following Toxoplasma infection. Data are presented as the relative expression level of pri-miR-17 ~ 92 in THP-1 cells following Toxoplasma infection in the presence or absence of siRNA as assessed by qRT-PCR. (C) A schematic illustration of pGL-based reporter constructs was used in dual luciferase assays to examine the transcriptional activity of the STAT3-BR in response to TgCtwh3 infection. Dotted lines indicated deleted region. (D) THP-1 cells were cotransfected with the indicated reporter constructs and Renilla luciferase plasmids. Twenty-four hours later, transcriptional activity was determined by luciferase assays. THP-1 cells with or without STAT3 knock-down by siRNA were cotransfected with the indicated reporter constructs and Renilla luciferase plasmids. Twenty-four hours later, cells were exposed to TgCtwh3 for another 24 h, followed by measurement of reporter activity by using luciferase assays. *, p,0.05 vs. non-treated cells (in B) or cells transfected with a control vector (in D) .Values are presented as mean ± SD (n =3 in A, B and D)