To further confirm the inhibitory role of PPARγ activation in the interruption of canonical Wnt signaling, HSCs were co-transfected with the plasmid TOPflash or FOPflash, plus the cDNA expression plasmid pPPARγ. Transfected cells were cultured for 24 hr in media with 10% FBS, which contains enough agonists to activate PPARγ in HSCs 19, 23, 24. Luciferase activity assays in Fig. 10B revealed that forced expression of PPARγ dose-dependently reduced luciferase activities in cells transfected with TOPflash, but not in cells transfected with FOPflash, confirming that the activation of PPARγ interrupted canonical Wnt signaling in HSCs. Additional experiments verified these observations and demonstrated that the activation of PPARγ by PGJ2 dose-dependently reduced luciferase activities in HSCs transfected with TOPflash (Fig. 10C). Taken together, these results indicated that the activation of PPARγ by curcumin resulted in the interruption of canonical Wnt signaling in activated HSCs in vitro.