Fig. 1.
Carbazole derivatives lengthen the circadian period. (A) The chemical structure of carbazole derivatives. (B and C) Luminescence rhythms of Bmal1-dLuc and Per2-dLuc reporter U2OS cells were monitored in the presence of various concentrations of compound. Representative traces (n = 2) are shown in (B). The changes of period and luminescence intensity (an average of 24–120 h; IC50 values are indicated in insets of bottom panels) relative to DMSO control are shown in (C) as mean ± SEM (n = 4). When arrhythmic, the period was not plotted. (D and E) Luminescence rhythms of mPer2Luc knock-in reporter in mouse SCN (D) and lung (E) explants were monitored in the presence of increasing concentration of KL001 (each for 120 h). Data are mean ± SEM (n = 6 for SCN and 5 for lung).