Interaction of Apoptotic Cells with Macrophages Upregulates COX-2/PGE2 and HGF Expression via a Positive Feedback Loop
Figure 8
TGF-1 induction in unstimulated macrophages in response to apoptotic cells is not notably suppressed by COX-2 inhibition. RAW 264.7 cells (a, b) or peritoneal macrophages (d, e) were pretreated with NS-398, indomethacin (Indo), or AH-6809 (AH) for 1 h and then stimulated with apoptotic Jurkat cells (ApoJ) for 2 h to detect TGF-1 mRNA expression (a, d) or for 24 h to detect secreted TGF-1 (b, e). RAW cells (c) or peritoneal macrophages (f, g) were transfected with COX-2 siRNA or control vehicle (siRNA-GFP) for 6 h and then stimulated with ApoJ for 2 h to detect TGF-1 mRNA expression, or for 24 h to detect secreted TGF-1. (h) Raw cells were pretreated with 10 μM NS-398, 10 μM AH-6809, or 10 μM PHA-665752 for 1 h and then stimulated with 1 μg/mL LPS and ApoJ. (a, d, f) TGF-1 mRNA levels were analyzed using semiquantitative RT-PCR and normalized to -actin mRNA levels. (b, c, e, g, h) TGF-1 levels in conditioned media were measured by ELISA. Values represent mean ± SEM of three or more separate experiments; .
