Figure 4.

Iloprost and Fzd 9 are specific in its activation of PPAR-RE and is not a generalized response to all prostaglandins, the effects are also blocked by sFRP1. (A) Iloprost and Fzd 9 activate PPARγ. The A549 and H1703 cell lines were transiently transfected with the PPAR-RE, sFRP1, Fzd 9, Wnt 7a, along with CMV-β-gal to normalize for transfection efficiency. After an overnight incubation, cells were exposed for 48 hours with 10 µM iloprost. (B) The H157 cell line was transiently transfected with PPAR-RE, Fzds (1–10), along with CMV-β-gal to normalize for transfection efficiency. After an overnight incubation, cells were exposed for 48 hours with 10 µM iloprost. (C) The cell line H157 was transiently transfected with the reporter plasmid PPAR-RE and the effector plasmid PGIS, or Fzd 9, or exposed to 10 µM PGE₂. Of note, CMV-β-gal was used to normalize for transfection efficiency. The cells were incubated for 48 hours, and luciferase and β-galactosidase activities were measured. Data are presented as relative light units/milliunit of β-galactosidase activity. The results showed that the coexpression of PGIS and Fzd 9 stimulated PPAR-RE activity but not the sole expression of PGIS, Fzd 9, or PGE₂. Furthermore, the coexpression of PGE₂ and Fzd 9 similarly did not stimulate PPAR-RE activity.