Implication of CYP for bioluminescence by luciferin analogue TokeOni in mice, pill bugs, and blow flies

<p>Bioluminescence imaging has become an essential part of life science research and has routinely used to detect target cells in various tissues and to monitor disease processes. By introducing genes of luminescent enzymes, luciferases, into the target sites, it is possible to detect light emission from there. Although the firefly bioluminescent system is the most widely used, the yellow-green light is not able to penetrate deeper through living organisms and has significant limitations for its use in bioluminescence imaging. To overcome the problem, we have developed three longer wavelength luciferin analogues, "AkaLumine", "TokeOni" and "SeMpai" based on the substrate of the firefly bioluminescence system, which are extremely transmissive to living organisms. Unexpectedly, without introduction of a luciferase gene, we observed the luminescence from the liver of mice in vivo when AkaLumine and TokeOni were administered. This luminescence was reduced by the treatment of CYP inhibitors, and was affected by liver diseases. In order to study the luminescence in other organisms, these analogues were added to the extracts of pill bugs and blow flies, and the luminescence was observed. This suggests that the new luminescence system is conserved in animals.</p>