ARTICLE Autonomous and self-sustained circadian oscillators

Aims/hypothesis Following on from the emerging impor-tance of the pancreas circadian clock on islet function and the development of type 2 diabetes in rodent models, we aimed to examine circadian gene expression in human islets. The oscillator properties were assessed in intact islets as well as in beta cells. Methods We established a system for long-term biolumines-cence recording in cultured human islets, employing lentivec-tor gene delivery of the core clock gene Bmal1 (also known as Arntl)-luciferase reporter. Beta cells were stably labelled using a rat insulin2 promoter fluorescent construct. Single-islet/cell oscillation profiles were measured by combined biolumines-cence–fluorescence time-lapse microscopy. Results Human islets synchronised in vitro exhibited self