The role of miR-1 in the regulation of phagocytosis in mammalian macrophages.

Abstract

<p>(A) Expression levels of miR-1 and phagocytic activities in the isolated murine macrophage, the immortalized macrophage ANA-1 and the cancerous macrophage RAW264.7. The expression of miR-1 was quantified with real-time PCR (left). The phagocytic activity was evaluated using FITC-labeled <i>E. coli</i> (right). The data referred to the means ± standard deviations of triplicate assays. (B) Overexpression of miR-1 in RAW264.7 and ANA-1 cells. Cells were transfected with miR-1 precursor or control miRNA. At 24 h after transfection, the total RNAs were isolated from transfected cells and subjected to Northern blot. The expression level of miR-1 was normalized with U6. (C) Evaluation of phagocytic activities in RAW264.7 and ANA-1 cells against FITC-labeled <i>E. coli</i> by flow cytometry. Cells transfected with miR-1 precursor or control miRNA were challenged with FITC-labeled <i>E. coli</i>, followed by phagocytosis assays. (D) Knockdown of miR-1 in RAW264.7 and ANA-1 cells. The cells were transfected with AMO-miR-1 or AMO-miR-1-scrambled. Twenty four hours later, the total RNAs were isolated from transfected cells. The expression of miR-1 was determined by quantitative real-time PCR. (E) Phagocytosis percentages of RAW264.7 and ANA-1 cells treated with AMO-miR-1 or AMO-miR-1 -scrambled. At 24 h after transfection of AMOs, the phagocytosis was evaluated using FITC-labeled <i>E. coli</i>. In all panels, plotted data points referred to the means ± standard deviations of triplicate assays and asterisks represented statistically significant differences (**, <i>p</i><0.01; *, <i>p</i><0.05).</p