The resetting of the circadian rhythm by Prostaglandin J2 is distinctly phase-dependent

The circadian rhythm can be reset by a variety of substances. Prostaglandin J2 (PGJ2) is one such substance and resets the circadian rhythm in fibroblasts. In our current study, we examined the phase-dependent phase shift following PGJ2 treatment using a real-time luciferase luminescence monitoring system. In the phase response curves, we observed 12 h differences in the times of peaks in comparison with the same analysis for forskolin. Quantification of clock gene mRNAs following PGJ2 administration additionally revealed a rapid decrease in the Per1, Rev-erbAα and Dbp levels. Our current findings thus suggest that PGJ2 resets the peripheral circadian clock via a mechanism that is distinct from that used by forskolin (FK).