MiRs-103/107 negatively regulate p38/AP-1 pathway in HLEKs via directly targeting MAP3K7.

<p>(A) HLEKs were treated with Ir-antago, Antago-103 or Antago-107 for 24 hours; then lysates were immunoblotted against phospho-p38 (p-p38), p38, phosphor-c-Jun (p-c-Jun), c-Jun and GAPDH. (B) Schematic diagrams of miR-103/107 binding sites in the 3’UTR region of MAP3K7 mRNA. Bold: seed sequences. (C) Screening the interaction of MAP3K7 with miR-103/107 using the psiCHECKTM-2 vector harboring 3’ untranslated region (UTR) of MAP3K7. Constructs were co-transfected with either miR-control, or miR-107 into cells. Twenty four hour after transfection, firefly and renilla luciferase activities were measured using the Dual-Luciferase Reporter Assay System. N: precursor microRNA control, 107: precursor microRNA-107. T test was performed. *p<0.05. (D) Immunoblotting of endogenous total MAP3K7, phospho-MAP3K7 and GAPDH following over-expression of either pre-miR-negative control (N), pre-miR-103(103), or pre-miR-107(107). (E) HLEKs were treated with Ir-antago, Antago-103 or Antago-107 for 24 hours and lysates were immunoblotted for total MAP3K7, phospho-MAP3K7 and GAPDH. Numbers below the panels represent the normalized expression signal of proteins.