Inhibition of LPS-stimulated TNF-α production by PTPN7 in RAW 264.7 cells.

<p>(A) Secretion levels of LPS-stimulated TNF-α were increased time-dependently in cell culture supernatants. At different times post treatment with LPS, culture supernatants were analyzed for TNF-α production using ELISA assay. (B) RAW 264.7 cells were transfected with either the empty vector or the construct expressing FLAG-PTPN7. After 16 h stimulation with LPS (1 µg/ml), supernatants were analyzed for TNF-α production using an ELISA assay, as described under Materials and Methods. Cell lysates were subjected to immunoblotting using an anti-FLAG antibody for detection of PTPN7. The results presented represent the mean data from three independent experiments. *<i>p</i><0.01 versus the vector controls (Student’s t-test). (C) PTPN7 knockdown (PTPN7 siRNA #1 and #2) was detected via immunoblotting using anti-PTPN7 and anti-tubulin antibodies. (D) After transfection with control or PTPN7 siRNAs (#1 and #2), cells were treated with LPS (1 µg/ml) for 1 h, and the levels of TNF-α were measured using an ELISA assay. The results presented represent the mean data from three independent experiments. **<i>p</i><0.05 versus the LPS-treated control siRNA (Student’s t-test).