1 research outputs found
Identification and Validation of Cryptochrome Inhibitors That Modulate the Molecular Circadian Clock
Circadian rhythms, biological oscillations with a period of about
24 h, are maintained by a genetically determined innate time-keeping
system called the molecular circadian clockwork. Despite the physiological
and clinical importance of the circadian clock, the development of
small molecule modulators that directly target the core clock machinery
has only been recently initiated. In the present study, we aimed to
identify novel small molecule modulators influencing the molecular
feedback loop of the circadian clock by applying our two-step cell-based
screening strategy based on E-box-mediated transcriptional activity
to test more than 1000 drug-like compounds. A derivative of 2-ethoxypropanoic
acid designated as compound <b>15</b> was selected as the most
promising candidate in terms of both efficacy and potency. We then
performed pull-down assays with the biotinylated compound and find
out that both cryptochrome (CRY)Â1 and 2 (CRY1/2), key negative components
of the mammalian circadian clock, as molecular targets of compound <b>15</b>. In accordance with the binding property, compound <b>15</b> enhanced E-box-mediated transcription in a CRY1/2-dependent
manner, and more importantly, it attenuated the circadian oscillation
of Per2-Luc and Bmal1-dLuc activities in cultured fibroblasts, indicating
that compound <b>15</b> can functionally inhibit the effects
of CRY1/2 in the molecular circadian clockwork. In conclusion, the
present study describes the first novel chemical inhibitor of CRY1/2
that inhibits the repressive function of CRY1/2, thereby activating
CLOCK-BMAL1-evoked E-box-mediated transcription. Further optimizations
and subsequent functional studies of this compound may lead to development
of efficient therapeutic strategies for a variety of physiological
and metabolic disorders with circadian natures