Interaction of Apoptotic Cells with Macrophages Upregulates COX-2/PGE2 and HGF Expression via a Positive Feedback Loop
Figure 5
Apoptotic cell-induced HGF production in murine peritoneal macrophages is dependent on COX-2/PGE2 signaling. (a, b) Murine peritoneal macrophages were stimulated with apoptotic (ApoJ) or viable (ViaJ) Jurkat cells for the times indicated. After 1 h of pretreatment of 10 μM NS-398 or 10 μM AH-6809 (AH), peritoneal macrophages were stimulated with ApoJ for 2 h to detect HGF mRNA (c) or for 24 h to detect HGF protein (d, e). (f, g) Peritoneal macrophages were transfected with COX-2 siRNA or control vehicle (siRNA-GFP) for 6 h and then stimulated with ApoJ for 24 h. (a, c) COX-2, COX-1, or HGF mRNA levels were analyzed using semiquantitative RT-PCR and normalized to -actin mRNA levels. (b, e, f) Immunoblots of total cell lysates were performed with anti-COX-2, COX-1, or HGF antibodies. (d, g) HGF levels in conditioned media were measured by ELISA. Values represent mean ± SEM of three or more separate experiments; .
