Ox-LDL-induced miR-155/SOCS-1 and pro-inflammatory responses in macrophages are regulated by the silencing of KLF2.

<p>The effects of silencing KLF2 on miR-155 expression in macrophages cultured alone or activated by ox-LDL were examined. Macrophages from WT C57BL/6 mice were infected with either viruses containing a nonspecific control siRNA (NS) or viruses containing siRNA-KLF2 for 24–48 h and then stimulated with ox-LDL (50 μg/ml) for 24 h. Total RNA was extracted and subjected to RT-PCR analysis to determine miR-155 mRNA expression levels. Bar graphs indicate relative miR-155 mRNA levels normalized to U6 mRNA levels (A). The effects of silencing KLF2 on SOCS-1 mRNA (B) and protein (C) expression levels in macrophages cultured alone or activated by ox-LDL were assessed. Data were normalized to an endogenous internal control reference gene (GAPDH for mRNA and β-actin for protein). The effects of silencing KLF2 on MCP-1, IL-6, and IL-10 mRNA expression in Mø cultured alone or activated by ox-LDL were examined. Bar graphs depict relative MCP-1, IL-6, and IL-10 mRNA levels normalized to GAPDH mRNA levels (D). Culture supernatants were evaluated by ELISA to determine levels of the cytokines MCP-1, IL-6, and IL-10 (E and F). All of the above data are presented as means ± S.D. for three independent experiments (with #, *, and δ indicating p<0.001, p<0.05, and p>0.05, respectively, for the indicated comparisons).